Aqua-Hot | AHE-100-02S-12 VDC | Service manual | Aqua-Hot AHE-100-02S-12 VDC Service manual

AHE-100-02S
SERVICE MANUAL
© 2011 Aqua-Hot Heating Systems Inc.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 2 —
Table of Contents
Section 1: Introduction to the Aqua-Hot AHE-100-02S
Introduction ............................................................................................................... ..Page 6-7
Danger, Warning, Caution, and Note Box Definitions................................................... ...Page 6
Section 2: Aqua-Hot Hydronic Heating System Overview
Technical Information ................................................................................................... ...Page 8
I.D. Label Sample ......................................................................................................... ...Page 9
Component Overview .................................................................................................Page 9-10
Aqua-Hot Operational Flow-Chart .............................................................................. ..Page 11
Section 3: Interior Switch Panel
Diesel-Burner Switch .................................................................................................. .Page 12
Electric Element Switch .............................................................................................. .Page 12
Engine Preheat Switch ............................................................................................... .Page 12
Section 4: Exhaust System Requirements
Exhaust System Requirements .................................................................................... .Page 13
Section 5: Aqua-Hot Components
Control Thermostat - Diesel Burner ..........................................................................Page 14-15
Control Thermostat - Electric Element......................................................................Page 16-17
A.C. High Limit Thermostat .......................................................................................... Page 18
D.C. High Limit Thermostat .......................................................................................... Page 19
Check Valves ...........................................................................................................Page 20-21
Tempering Valve ......................................................................................................Page 22-23
Circulation Pumps C, B & A .....................................................................................Page 24-25
Stir Pump .................................................................................................................Page 26
Engine Preheat Pump ..............................................................................................Page 27-28
Interior Zone Relay - Interior Heat Exchanger Fans/Zone Pumps ............................Page 29-30
Electric Heating Element ..........................................................................................Page 31-32
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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Table of Contents
Section 6: Diesel-Burner
Overview ................................................................................................................ Page 33-38
I.D. Plate ...................................................................................................................... Page 33
Diesel-Burner Overview ......................................................................................... Page 33-34
Diesel-Burner Operational Flow Chart .......................................................................... Page 35
Diesel-Burner Operational Overview ...................................................................... Page 36-38
Section 7: Detaching and Reattaching the Diesel-Burner
Detaching the Diesel-Burner .................................................................................. Page 39-42
Reattaching the Diesel-Burner ............................................................................... Page 43-44
Section 8: Diesel-Burner Components / Trouble Shooting
Troubleshooting Flow Chart ................................................................................... Page 45-49
Motor ...................................................................................................................... Page 50-53
Flame Sensor ......................................................................................................... Page 54-55
Ignition Electrodes .................................................................................................. Page 56-57
Fuel Nozzle ............................................................................................................ Page 57-58
Fuel Solenoid ............................................................................................................... Page 59
Fuel Pump .............................................................................................................. Page 60-62
Bearings ................................................................................................................. Page 63-65
Ignition Coil ............................................................................................................ Page 66-67
Controller ................................................................................................................ Page 68-69
Section 9: General Troubleshooting
If the Aqua-Hot is Black Smoking ................................................................................. Page 70
If the Aqua-Hot is Blue/White Smoking ........................................................................ Page 71
If one of the Aqua-Hot’s Heating Zones will not get hot................................................ Page 72
If there is a lack of domestic continuous hot water ....................................................... Page 73
If there is antifreeze leaking ................................................................................... Page 74-75
Appendix A: Wiring Diagram .........................................................................................Page 76-77
Appendix B: BLEEDING
THE INTERIOR
HEATING ZONE CIRCULATION PUMP .....................Page 78-82
Appendix C: Fuel Pressure check and Adjustment .....................................................Page 83-86
Appendix D: Extreme Cold Weather Operation ............................................................Page 87-88
Appendix E: Aqua-Hot Annual Maintenance ..............................................................Page 89-102
Appendix F: Winterization Process .................................................................................. Page 103
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 1: INTRODUCTION
This service and parts manual is designed to aid
trained and qualified service technicians with
the process of troubleshooting and servicing the
Aqua-Hot AHE-100-02S Hydronic heating system.
The Aqua-Hot AHE-100-02S heating system features a 12
Volt-DC powered diesel-burner and a 120 Volt-AC, 1650
Watt electric heating element. These two heating sources are
used in conjunction with an antifreeze/water heating solution
in order to provide a continuous supply of domestic hot water, interior/fresh water tank heating, independent interior
zone heating, and engine preheating. Be sure to reference
Figures 3 for a complete component overview.
Please note that all Danger, Warning, Caution, and Note boxes, appearing as needed throughout this manual, must be
reviewed and adhered to during any service procedure in
order to avoid potential hazards, which could result in injury,
product damage, or property damage.
Should additional assistance be needed, please contact the
technical support department at 1-800-685-4298, Monday
through Friday, between the hours of 7:00 AM and 4:00 PM
Mountain Standard Time.
Danger, Warning, Caution, and Note Boxes:
Danger, Warning, Caution, and Note boxes appear throughout this manual as a means of alerting the service technician
to important information.
INDICATES THAT PERSONAL INJURY IS LIKELY OR
IMMINENT.
TO THE
AQUA-HOT AHE-100-02S
Understanding the Aqua-Hot AHE-100-02S Major
Systems:
The basis for the Aqua-Hot heating system’s functionality is
the antifreeze and water heating solution, which is comprised
of water that is distilled, de-ionized, or soft, as well as antifreeze. Through this solution’s ability to maintain and transfer heat, the Aqua-Hot’s three major systems: the domestic
water system, engine preheat system, and interior heating
system, are able to function effectively. This antifreeze and
water heating solution is contained within the Aqua-Hot’s
boiler tank and is heated by the diesel-burner when its operating criteria are met and/or the electric heating element
when its operating criteria are met. In order for the dieselburner to be considered as a heating source by the Aqua-Hot,
it must have an adequate fuel supply, receive power from the
fuse block, and be selected as a heating source from the interior switch panel. In order for the electric heating element to
be considered as a heating source by the Aqua-Hot, it must
receive power from either a generator or from shore power
and be selected as a heating source. Once the antifreeze and
water heating solution achieves operating temperature (as
determined by the Aqua-Hot’s control thermostat), the domestic water system, the engine preheat system, and the interior heating system are permitted to operate as needed.
Domestic Hot Water System:
When hot water is requested, domestic water from the motor
home’s fresh water tank is transported through a copper coil
around the Aqua-Hot’s boiler tank where heat is transferred
from the heated antifreeze and water heating solution to the
domestic water flowing through the copper coil. The heated
domestic water then flows through the tempering valve to be
mixed with cool water from the fresh water tank to achieve
an appropriate temperature before it flows to the faucet requesting hot water.
Indicates that serious damage to the heater will occur
and personal injury is possible as well.
Indicates that damage to the heater is possible.
NOTE: Indicates information that requires special attention by the service technician
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 1: INTRODUCTION
Engine Preheat System:
The engine preheat system is responsible for heating the motor home’s engine block in order to make it easier to start-up
when cool weather conditions exist.
When the engine preheat system is activated via the interior
switch, the motor home’s engine coolant is circulated
through a dedicated copper coil in the Aqua-Hot’s boiler
tank, where heat from the antifreeze and water heating solution is transferred to the motor home’s engine coolant. The
heated engine coolant is then transported back to the engine
where it transfers the heat to the engine to gradually warm it.
Additionally, the Aqua-Hot includes a motor-aide feature,
which uses the circulation of the motor home’s engine to
transport the engine’s coolant from the Aqua-Hot’s boiler
tank to the motor home’s warm engine and back to the boiler
tank. Through this process, the boiler tank is kept heated,
which reduces the time required to bring the tank to operating temperature for interior heat and continuous domestic hot
water. This motor-aide feature is part of the engine preheating feature and plumbing system, and requires no action on
the user’s behalf to function.
Interior Heating System:
The interior heating system is responsible for providing heat
to the motor home’s interior in order to maintain the temperature at a comfortable level.
TO THE
AHE-100-02S
For interior heating, it is the room thermostats that trigger the
Aqua-Hot’s interior heating system. When a thermostat recognizes that heat is required in a particular area, it sends a
signal to the Aqua-Hot’s corresponding zone relay. The
Zone Relay responds by activating the circulation pump for
that zone, which sends the heated antifreeze and water heating solution through the Heating Loop corresponding to the
zone requesting heat. The fans on the heat exchangers in the
zone calling for heat are also activated; therefore, as the heated solution flows over the heat exchanger’s fins, the heat is
transferred to those fins and dispersed into the interior of the
motor home by the fans. Until the thermostat signals that
heat is no longer required, the Aqua-Hot will continue to
send the heated antifreeze and water solution through the
loop, which returns the cooled solution to the Aqua-Hot’s
boiler tank to be re-heated before being sent back through
the loop again. This process continues until the pre-set temperature of the interior is reached, and the interior room thermostat signals the electronic controller that heat is no longer
required.
AC Circuit:
Although the diesel-burner is the primary heating source for
the Aqua-Hot and is necessary for providing continuous domestic hot water, an alternate heat source exists for moderate
temperatures, which functions with an AC circuit. Whenever
the motor home is connected to an AC power source plugged into shore power or using a generator, the AquaHot’s electric heating element has the ability to function in
order to provide heat for the boiler tank.
When the antifreeze and water heating solution falls below
operating temperature (as determined by the control thermostat), the control thermostat closes, and allow AC power to
flow to the electric heating element. When the electric heating element receives power, it becomes active and supplies
heat to the boiler tank until operating temperature is reached.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 2: AQUA-HOT AHE-100-02S OVERVIEW
Figure 1
Aqua-Hot AHE-100-02S Technical Specifications
Diesel-Burner, Heat Input (Firing Rate) ................................................................................................................................................ 50,000 BTU/hr
Diesel-Burner, Fuel Consumption (Continuous Operation) ......................................................................................................................0.50 gal/hr
Heater, Voltage/Maximum Power Consumption .................................................................................................................... 12 Volt-DC/60 watts
Electric Heating Element specifications ................................................................................................................................ 120 Volt-AC/1650 watts
Zone Heat Circulation Pump specifications .........................................................................................(3) 12 Volt-DC/12 watt 3.5gpm Flow Rate
Number of Heating Zones ................................................................................................................................... maximum of 3 plus Engine Preheat
Domestic Water Heating Capacity ...........................................................................................................................................continuous/on-demand
Antifreeze Type Used ...............................................................................................................................................................................Ethylene Glycol
Dimensions ........................................................................................................................................................................... 18.5”H x 18.5”W x 36.75”L
Dry Weight ...................................................................................................................................................................................... approximately 200lbs.
NOTE: All vehicle installations must comply with the requirements listed in the Recreational Vehicle Industry Association’s
(RVIA) ANSI/NFPA 1192 Handbook for Recreational Vehicle Standards. To receive a copy of this handbook and other pertinent RVIA Standards, write to: Recreation Vehicle Industry Association, 1896 Preston White Drive, P.O. Box 2999, Reston,
VA 22090-0999, call them at (703) 620-6003, or visit them online at www.rvia.org.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 2: AQUA-HOT AHE-100-02S OVERVIEW
Figure 2
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 2: AQUA-HOT AHE-100-02S OVERVIEW
Figure 3
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 2: AQUA-HOT AHE-100-02S OVERVIEW
Heat Source is
selected
“Diesel Burner”
Switch Turned On
“Electric Element”
Switch Turned On
Diesel-Burner heat
source selected by
Diesel-Burner Switch
Electric Heating Element
heat source selected by
Electric Element Switch
Diesel-Burner fires
into the Combustion
Chamber, which heats
the antifreeze and water heating solution in
the Boiler Tank
Electric Heating Element
activates, which heats the
antifreeze and water heating solution in the Boiler
tank
Boiler Tank
heats to 200 °F
NOTE: The DieselBurner and/or Electric
Heating Element (as
switched ON) will automatically begin reheating the antifreeze and
water heating solution
drops below:
175°F - Diesel
184 °F - Electric
Boiler Tank
heats to 210 °F
Zone Thermostat
calls for heat
The Engine Preheat
switch on the Interior
of the Motor Home is
activated.
The Circulation
Pump activates for
the Zone which
called for heat. The
heated antifreeze
and water heating
solution is transported throughout
the plumbing lines
the that zone.
Heat is transferred to
the Engine Preheat
System
The cooled antifreeze
and water heating solution is returned to the
Boiler Tank to be reheated
Heat Exchanger
fans activate
Heat is transferred into
the Zone calling for
heat
Antifreeze and water heating solution
moves through the
Heat Exchangers in
the Zone calling for
heat
The engine’s coolant
is circulated through
the Aqua-hot’s internal Engine Preheat
System, where the
heat from the Boiler
Tank is transferred to
the engine’s coolant.
A hot water faucet (e.g.,
kitchen sink, shower,
etc.) calls for hot water
Heat is transferred to
the Domestic Water
System
Continuous hot water is
supplied to the faucet
The antifreeze and
water heating solution
within the Boiler Tank
is reheated, as needed,
and continues warming the engine’s coolant as it circulates
through the Aquahot’s internal Engine
Preheat System
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 3: INTERIOR SWITCH PANEL
NOTE: The Interior switches are supplied by the OEM.
Electric Element Switch:
NOTE: If a 12 VDC switch is used to activate the 120 VAC
heating element, there will be a relay, which the 12 VDC
switch will activate to allow 120VAC power to be supplied
to the 120VAC heating element.
Diesel-Burner Switch:
When the diesel-burner switch is in the on position, any time
the control thermostat tells the Diesel Burner that heat is
needed for the boiler tank, the diesel-burner will respond by
firing up and providing heat. A cold boiler tank can expect
to be brought to operating temperature by the diesel-burner
in approximately 20 to 30 minutes. In order to obtain continuous hot water, the diesel-burner switch must be activated.
NOTE: If the diesel-burner fails to ignite, the diesel burner
status light will go out, indicating to the customer the burner has gone into a default. To reset the default, the diesel
burner switch must be turned off for 5 seconds and then
turned back on.
When the motor home is plugged into an AC power source
(e.g., shore power, generator, etc.) and the electric element
switch is on, the electric heating element will be used to provide heat to the boiler tank if the need arises. A cold boiler
tank can expect to be brought to operating temperature by the
electric heating element in approximately 1 to 2 hours. The
electric element, alone, will not be able to provide continuous hot water.
Engine Preheat Switch:
The engine preheat switch activates the engine preheat
pump, which draws the motor home’s engine coolant
through the boiler tank to heat it before returning it to the
engine block to transfer the heat there. The engine preheat
switch does not need to be activated for the motor-aide feature to work and should be shut off when traveling.
Figure 4
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 4: EXHAUST SYSTEM REQUIREMENTS
Because the Aqua-Hot’s exhaust is hot and must be kept
away from any heat-sensitive material, the exhaust system
should be checked to ensure that it continues to meet the
following requirements:

The exhaust must not be directed downward as a fire
could result when parked in dry, grassy areas.

The exhaust must not terminate underneath the vehicle,
underneath an open-able window or vent, in the awning
area of the motor home (if applicable), or near slide-out
areas.

The exhaust must be able to freely exit away from the
vehicle without any obstructions.

1 3/4” - 2” standard automotive-type exhaust piping
should be used with a maximum of two 90-degree pipe
bends and should not exceed 20 feet.

The 3-inch and 4-inch black-pipe nipples and the exhaust elbow - originally supplied with the Aqua-Hot,
must be present.
Figure 5
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 5: AQUA-HOT COMPONENTS
Figure 6
190 º F Diesel Burner
Control Thermostat
Thermostats
2.
Control Thermostat: Diesel Burner
The Diesel Burner control thermostat is installed onto the
Aqua-Hot’s boiler tank and monitors the temperature of the
antifreeze and water heating solution to determine when it is
at operating temperature and when it requires heat. The Aqua-Hot’s Diesel Burner is considered to be at operating temperature between 175°F and 200°F.
If the Diesel Burner Does not come on and run:
A. Verify that the temperature of the boiler tank has
fallen below the 175°F minimum operating temperature by checking with a digital thermometer.
B. Disconnect the control thermostat’s wires from their
connections, and, using an ohmmeter, check for
continuity.
Troubleshoot the control thermostat if one of the following
conditions has occurred:
If there is no continuity, follow the instructions in
this section for replacing the control thermostat.



If continuity exists, complete the following:
There is a lack of hot domestic water and interior heat.
The Diesel Burner does not operate
Excessive Blue or white smoke is expelled from the exhaust.
Troubleshooting:
1.
a.
Inspect the control thermostat’s wiring and
connections.
b.
Verify the Diesel Burner’s Controller is sending power to the control thermostat.
Turn the diesel-burner switch on the interior switch panel on.
If the Diesel Burner comes on and runs, but there is still
a lack of hot water verify that the control thermostat is
operating within the proper operating temperature range.
A. Using a digital temperature sensor, place the probe on
the tank next to the thermostat. The proper
operating temperature for the diesel burner is
175°F - 200°F.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 5: AQUA-HOT COMPONENTS
Control Thermostat Replacement Procedure:
Note: If a screw longer than 1/4” is used to secure the
FAILURE TO DISCONNECT ALL POWER SUPLIES AND/OR TO
thermostat in place, it may cause the thermostat mounting
bracket to be pushed away from the boiler tank, and may
result in overheating.
ALLOW THE HEATER TO COOL BEFORE SERVICING COULD
CAUSE SERIOUS DAMAGE OR PERSONAL INJURY.
5.
Ensure that the Aqua-Hot has been completely shut
down and that all power sources have been disconnected. Also, because this replacement procedure will involve the boiler tank and the potential for hot coolant, be
sure the heater has adequately cooled.
Inspect the quick connectors on the thermostat wires.
Replace if necessary. Re-Connect the control thermostat’s wires (orange and white).
6.
Test the Aqua-Hot for normal operation.
2.
Disconnect the defective control thermostat’s wires by
separating the quick-disconnect terminals.
hooked up to the wrong thermostat, the diesel burner will
default every time the heater reaches the maximum operating temperature.
3.
Using a 1/4” nut driver, unscrew the two screws securing the control thermostat to the Aqua-Hot’s boiler tank
thermostat mounting bracket.
4.
Install the replacement control thermostat into the thermostat mounting bracket and secure with the two screws
previously removed.
1.
Note: If the control and overheat thermostat wires are
Figure 7
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 5: AQUA-HOT COMPONENTS
Figure 8
198 º F Electric Element
Control Thermostat
Thermostats
1. Disconnect all power supplies.
Control Thermostat: Electric Element
2.
Remove the thermostat access cover.
The Electric Element control thermostat is installed onto the
Aqua-Hot’s boiler tank and monitors the temperature of the
antifreeze and water heating solution to determine when it is
at operating temperature and when it requires heat. The Aqua-Hot’s Electric Element is considered to be at operating
temperature between 185°F and 210°F.
3.
Verify that the boiler tank’s temperature is below 230°F.
4.
Locate the AC control thermostat and remove its wires,
by loosening and removing the screws securing the
wires in place.
5.
Using an ohmmeter, check the thermostat for continuity.
Troubleshoot the control thermostat if one of the following
conditions has occurred:

If continuity is not present, follow the instructions in
this section to replace the AC control thermostat.
There is a lack of hot domestic water and interior heat.
NOTE: For continuous domestic hot water to be present,
the diesel-burner must also be selected as a heating source.

The Electric Element does not operate
Troubleshooting:
NOTE: The Motor Home must be plugged into shore power, or the generator must be operating for the electric element to be working.
NOTE: The Motor Home’s Manufacturer may not have
installed a switch for the electric element. If that is the case
ensure the A.C. breaker for the Aqua Hot’s electric element
is in the “ON” position.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 5: AQUA-HOT COMPONENTS
Control Thermostat Replacement Procedure:
Note: If a screw longer than 1/4” is used to secure the
FAILURE TO DISCONNECT ALL POWER SUPLIES AND/OR TO
thermostat in place, it may cause the thermostat mounting
bracket to be pushed away from the boiler tank, and may
result in overheating.
ALLOW THE HEATER TO COOL BEFORE SERVICING COULD
CAUSE SERIOUS DAMAGE OR PERSONAL INJURY.
1.
Ensure that the Aqua-Hot has been completely shut
down and that all power sources have been disconnected. Also, because this replacement procedure will involve the boiler tank and the potential for hot coolant, be
sure the heater has adequately cooled.
2.
Disconnect the defective control thermostat’s wires by
removing the screws securing the wires to the terminals.
3.
Using a 1/4” nut driver, unscrew the two screws securing the control thermostat to the Aqua-Hot’s boiler tank
thermostat mounting bracket.
4.
Install the replacement control thermostat into the thermostat mounting bracket and secure with the two screws
previously removed.
5.
Inspect the wires going to the control thermostat Replace if necessary. Re-Connect the control thermostat’s
wires and secure in place using the screws previously
removed.
6.
Test the Aqua-Hot for normal operation.
NOTE: The Motor Home must be plugged into shore power, or the generator must be operating for the electric element to be working.
Figure 9
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 5: AQUA-HOT COMPONENTS
AC High-Limit Thermostat:
The AC high-limit thermostat serves as a safety measure in
the event that the electric heating element continues to operate after the maximum operating temperature is reached.
The high-limit thermostat allows the current for the heating
element to pass through it until the boiler tank reaches a temperature of 230°F. Should this temperature be reached, the
high-limit thermostat blocks the current to the element,
which prevents it from continuing to provide heat to the boiler tank.
Troubleshoot the AC high-limit thermostat if the following
condition has occurred:

Replacement Procedure:
FAILURE TO DISCONNECT ALL POWER SUPPLIES AND/OR
TO ALLOW THE HEATER TO COOL BEFORE SERVICING
COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY.
1.
Ensure that the Aqua-Hot has been completely shut
down and that all power sources have been disconnected. Also, because this replacement procedure will involve the boiler tank and the potential for hot coolant, be
sure the heater has adequately cooled.
2.
Disconnect the defective thermostat’s wires by removing the screws securing the wires to the terminals.
3.
Using a 1/4” nut driver, unscrew the two screws securing the thermostat to the Aqua-Hot’s boiler tank thermostat mounting bracket.
4.
Install the replacement thermostat into the thermostat
mounting bracket and secure with the two screws previously removed.
The electric heating element fails to operate.
Troubleshooting:
1.
Disconnect all power supplies.
2.
Remove the thermostat access cover.
3.
Verify that the boiler tank’s temperature is below 230°F.
4.
Locate the AC high-limit thermostat and remove its
wires.
5.
Using an ohmmeter, check the thermostat for continuity.
If continuity is not present, follow the instructions in this
section to replace the AC high-limit thermostat.
Note: If a screw longer than 1/4” is used to secure the
thermostat in place, it may cause the thermostat mounting
bracket to be pushed away from the boiler tank, and may
result in overheating.
5.
Inspect the wires going to the thermostat, Replace if
necessary. Re-Connect the thermostat’s wires and secure in place using the screws previously removed.
6.
Test the Aqua-Hot for normal operation.
Figure 10
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SECTION 5: AQUA-HOT COMPONENTS
Replacement Procedure:
DC High-Limit Thermostat:
The DC high-limit thermostat serve as a safety measure in
the event that the diesel-burner continues to operate after the
maximum operating temperature is reached. The high-limit
thermostat allow the current for the diesel-burner to pass
through it until the boiler tank reaches a temperature of
230°F. Should this temperature be reached, the high-limit
thermostat blocks the current to the diesel-burner’s fuel solenoid valve, which prevents the diesel-burner from operating.
FAILURE TO DISCONNECT ALL POWER SUPLIES AND/OR TO
ALLOW THE HEATER TO COOL BEFORE SERVICING COULD
CAUSE SERIOUS DAMAGE OR PERSONAL INJURY.
1.
Ensure that the Aqua-Hot has been completely shut down
and that all power sources have been disconnected. Also,
because this replacement procedure will involve the boiler
tank and the potential for hot coolant, be sure the heater
has adequately cooled.
2.
Disconnect the defective thermostat’s wires by separating
the quick-disconnect terminals.
3.
Using a 1/4” nut driver, unscrew the two screws securing
the control thermostat to the Aqua-Hot’s boiler tank thermostat mounting bracket.
4.
Install the replacement thermostat into the thermostat
mounting bracket and secure with the two screws previously removed.
Troubleshoot the DC high-limit thermostat if the following
condition has occurred:

The fuel solenoid on the diesel-burner fails to operate.
Troubleshooting:
1.
Place a jumper wire between the blue and purple wires
on the diesel-burner’s wire harness to bypass the highlimit thermostats. Check the Aqua-Hot for normal operation.
NOTE: Bypassing the high-limit thermostats is for testing
only and must not be used for the Aqua-Hot’s normal functioning.
2.
Note: If a screw longer than 1/4” is used to secure the
thermostat in place, it may cause the thermostat mounting
bracket to be pushed away from the boiler tank, and may
result in overheating.
Disconnect the DC high-limit thermostats’ wires, then,
using an ohmmeter, check the thermostat for continuity.
If there is no continuity, complete the following, follow
the instructions in this section to replace the high-limit
thermostat.
Figure 11
5.
Inspect the quick connectors on the thermostat wires. Replace if necessary. Re-Connect the thermostat’s wires
(blue and purple).
6.
Test the Aqua-Hot for normal operation.
Note: If the control and overheat thermostat wires are
hooked up to the wrong thermostat, the diesel burner will default every time the heater reaches the maximum operating
temperature.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 5: AQUA-HOT COMPONENTS
Figure 12
Valves
Check Valve:
With the circulation pump operating, tap on the check
valve and wait five minutes to evaluate if interior heat is
now present.
Check valves are installed into the zone outlet ports for each
heating loop to ensure that the antifreeze and water heating
solution only flows in one direction. If the heating solution
attempts to backflow into the boiler tank, the check valve
closes to prevent that from happening.
If interior heat is present after tapping the check valve,
the check valve was stuck closed and no further action is
necessary.
2.
3.
Troubleshoot the check valves if the following condition has
occurred:

There is a lack of interior heat in a particular zone.
NOTE: Before Troubleshooting the zone check valve it is
important to remember that if the zone circulation pump is
air locked, or if there is a kink in a zone heating loop plumbing line, the customer will experience the same symptoms as
a stuck check valve.
Check the Aqua-Hot’s antifreeze and water heating solution’s ratio of water to antifreeze. The mixture ratio
should be approximately 50/50. If the solution is comprised fully of antifreeze (100%), the check valves will
continue to stick.
NOTE: Storing the motor home for an extended period of
time can cause the check valves to stick. If, after the initial
release of the stuck check valve, it continues to stick, follow
the instructions in this section to replace the check valve.
Replacement Procedure:
Troubleshooting:
1.
Verify that the heating zone is operating properly by
checking the following:
FAILURE TO DISCONNECT ALL POWER SUPPLIES AND/OR
TO ALLOW THE HEATER TO COOL BEFORE SERVICING
COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY.
A. Verify that the room thermostat inside the interior
of the motor home is on and calling for heat.
B. Check the circulation pump for operation by feeling
the pump for a vibration, indicating the pump is
running.
1.
Ensure that the Aqua-Hot has been completely shut
down and that all power sources have been disconnected. Also, because this replacement procedure will involve the boiler tank and the potential for hot coolant, be
sure the heater has adequately cooled.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 5: AQUA-HOT COMPONENTS
Replacement Procedure: (continued)
2.
3.
Shut off both the return and the supply ball valves coming out of the aqua hot’s boiler tank..
Zone Ball
Valve
Disconnect the interior heating zone line from the defective check valve..
Figure 13
NOTE: When the interior heating zone line is disconnected
from the check valve, approximately 2 quarts of antifreeze
will leak out of the interior heating zone line.
4.
Unscrew the defective check valve from the Aqua-Hot’s
zone circulation pump.
5.
Install the replacement check valve onto the Aqua-Hot’s
zone circulation pump. The arrow on the check valve
must point away from the circulation pump.
6.
Reconnect the interior heating zone fitting and line to
the replacement check valve.
7.
Refill the Aqua-Hot boiler tank with the antifreeze and
water heating solution.
8.
Test for proper operation
NOTE: The Aqua Hot zone circulation pump is not a self
priming pump. If the circulation pump gets an air pocket, it
will be necessary to bleed the air out of the zone circulation
pump. Reference appendix ? For the proper zone circulation
pump bleeding procedure.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 5: AQUA-HOT COMPONENTS
Tempering Valve:
The tempering valve for the Aqua-Hot mixes the heated domestic water from the boiler tank with cold domestic water at
a preset ratio to reduce the risk of scalding.
Troubleshoot the tempering valve if the following condition
has occurred:

NOTE: Prior to trouble shooting the tempering valve, it is
recommended to review the Lack of Hot Water TroubleShooting guide in section 9.
NOTE: If the Hot line coming out of the Aqua Hot into the
tempering valve is hot, but the mix side of the tempering
valve is luke warm/cold, The tempering valve may be
faulty.
2.
3.
Follow the instructions for removing the diesel burner..
4.
Using Channel Lock Pliers, remove the Thermostat and
Bonnet Assembly.
5.
Once the thermostat and bonnet assembly has been re
moved, replace the o-ring, stainless steel spring, and
thermostat.
6.
Re-Install the bonnet assembly, and tighten with channel
lock pliers.
7.
Turn the motor home’s water pump back on and check
for leaks.
8.
Follow the instructions for re-installing the diesel burner.
9.
Turn the diesel burner on and let the heater come up to
full operating temperature.
There is a lack of hot domestic water.
Troubleshooting:
1.
3.
Inspect the tempering valve to ensure that it is not
leaking.
Test the temperature of the hot water using a digital
thermometer at one of the hot water faucets. Water
Temperature should range between 115° F - 123° F. If
the proper range cannot be set follow the instructions in
this section to replace the tempering valve.
Test the tempering valve’s functionality by turning the
knob.
10. Test heater for proper operation. Verify that the
replacement tempering valve has been set to the proper
setting by taking a digital thermometer to a hot water
faucet and set the water temperature between
115ºF - 123ºF .
FAILURE TO PROPERLY SET THE HOT WATER
TEMPERATURE BETWEEN 115ºF - 123ºF COULD
RESULT IN SEVERE BURNS.
If the tempering valve’s knob does not turn freely, follow the instructions in this section to replace the tempering valve’s internal components
Replacement Procedure:
FAILURE TO DISCONNECT ALL POWER SUPPLIES AND/OR
TO ALLOW THE HEATER TO COOL BEFORE SERVICING
COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY.
1.
Turn the motor home’s water pump off.
2.
Drain the water pressure by opening the faucets and allowing the water to drain.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 5: AQUA-HOT COMPONENTS
Tempering Valve:
Figure 14
Thermostat and Bonnet
Assembly
Spring
O-Ring
Thermostat
Tempering
Valve
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 23 —
SECTION 5: AQUA-HOT COMPONENTS
Pumps
Circulation Pumps A, B, and C:
The Zone circulation pump first draw the heated antifreeze
and water heating solution from the Aqua-Hot’s boiler tank,
then propel it through the hydronic heating system’s interior
heat plumbing.
Replacement Procedure:
FAILURE TO DISCONNECT ALL POWER SUPPLIES AND/OR
TO ALLOW THE HEATER TO COOL BEFORE SERVICING
COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY.
1.
Ensure that the Aqua-Hot has been completely shut
down and that all power sources have been disconnected. Also, because this replacement procedure will involve the potential for hot coolant, be sure the heater is
adequately cooled.
2.
Shut off both the return and the supply ball valves coming out of the aqua hot boiler tank..
3.
Disconnect the interior heating zone line from the check
valve.
Troubleshoot the Zone circulation pumps if the following
condition has occurred:


The Zone circulation pump is not operating.
There is a lack of heat in the coach.
Troubleshooting:
NOTE: Reference wiring Schematic in Appendix A.
1. Turn on the interior room thermostat corresponding to the
Zone pump not operating.
A. Using a Volt Meter , Check for voltage on the Fuse
Block for the zone pumps, Fuse C.
a. If No voltage, replace the fuse.
b. If Yes continue.
B. Using a Volt Meter, Check and ensure that the corresponding zone relay is sending voltage to the
pump at pin 6.
a. If No voltage is present troubleshoot the
zone relay.
b. If Yes continue.
C. Check the Zone pump for voltage.
a. If there is voltage and the zone pump is not
operating, follow the zone pump
replacement procedure in this book.
NOTE: Before Replacing the Pump remove and inspect the
brushes on the pump. If they are less than 1/8” the brushes
are to worn and will prevent the pump from operating.
NOTE: The zone pump can be tested by connecting it to
an external 12 Volt-DC power source to verify that the pump
is defective.
NOTE: When the interior heating zone line is disconnected
from the check valve, approximately 2 quarts of antifreeze
will leak out of the interior heating zone line.
4.
Unscrew the check valve from the Aqua-Hot zone
circulation pump.
NOTE: Once the check valve is removed there is pump nut,
securing the pump in place that will also need to be
removed.
5.
Disconnect the defective circulation pump’s wires by
removing the protective loom, and cutting both the positive and negative wires with wire cutters.
6.
Using a 3/4” and a 1 1/8” wrench disconnect the union
securing the zone circulation pump in place.
7.
Remove the zone circulation pump.
8.
Using a 1” wrench remove the copper pump stand from
the defective pump.
NOTE: Be sure to install the copper pump stand onto the
inlet side of the zone circulation pump. Reference Fig. 15
9.
Wrap the threads of the new replacement pump with a
thread seal tape.
10. Install the copper pump stand onto the replacement zone
circulation pump, and tighten down with a 1” wrench.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 5: AQUA-HOT COMPONENTS
11. Install the replacement pump onto the Aqua Hot, and t
tighten down the union previously loosened.
Be sure to review the wiring schematic in appendix A
for proper pump wiring.
12. Re-Install the check valve onto the Aqua-Hot zone circulation pump. The arrow on the check valve must
point away from the circulation pump.
15. Refill the Aqua-Hot boiler tank with the antifreeze and
water heating solution.
13. Reconnect the interior heating zone fitting and line to
the check valve.
14. Reconnect the wires on the replacement pump to the
wire harness on the heater by using a red butt connector.
NOTE: The Aqua Hot zone circulation pump is not a self
priming pump. If the circulation pump gets an air pocket, it
will be necessary to bleed the air out of the zone circulation
pump. Reference appendix B For the proper zone circulation pump bleeding procedure.
Figure 15
Check Valve
Back view of
pump
Copper
Pump Stand
C
B
A
Union
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 5: AQUA-HOT COMPONENTS
Stir Pump / Circulation Pump B:
The stir pump circulates the antifreeze and water heating
solution within the Aqua-Hot boiler tank in order to ensure
even-heating of the solution. To accomplish this, the stir
pump draws the solution from the supply port of the tank and
deposits it back into the return port of the tank, after circulation through heating loop number 2.
Troubleshoot the stir pump if the following condition has
occurred:


There is a lack of hot domestic water.
The Stir Pump does not operate when the diesel burner
is running.
NOTE: In order for the stir pump to operate, the dieselburner motor must be running.
Troubleshooting:
1. 1. Verify that the Diesel Burner motor is running.
2.
C. Using a Volt Meter check the #2 zone pump for
voltage.
If voltage is present and the pump still fails to operate follow the circulation pump replacement procedure in this book.
3. If it is determined that the pump is active, verify that the
pump is operating properly by checking both connected
hoses for heat.
If both hoses are hot, the pump is working properly.
If one hose is hot, or neither hose is hot, check the
the heating loop for a blockage (i.e. stuck check
valve, kinked line). If no blockage exists, follow
the instructions in this section to replace the Zone
pump #2.
Stir Pump/
Circulation
pump B
Figure 16
If the diesel burner motor is running and the stir pump
still is not operating:
A. Locate the Diode Wire which runs from the diesel
burner Controller C-2 pin, and hooks up to the BZone Relay Pin 6 terminal.
i.
Verify the Diode Wire is connected and the
screw for Pin 6 on the B-Zone relay is tight.
If diesel burner motor is running, and no voltage is
present at Pin 6 on the B-Zone Relay replace the
diode wire. If voltage is present at Pin 6 on the BZone Relay continue.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 26 —
SECTION 5: AQUA-HOT COMPONENTS
Pumps
Engine Preheat Pump:
The Engine Preheat circulation pump draws the cold antifreeze and water heating solution from the motor home’s
engine and then propels it through the Engine Preheat Heat
exchanger, located inside the boiler tank.
Replacement Procedure:
FAILURE TO DISCONNECT ALL POWER SUPPLIES AND/OR
TO ALLOW THE HEATER TO COOL BEFORE SERVICING
COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY.
1.
Ensure that the Aqua-Hot has been completely shut
down and that all power sources have been disconnected. Also, because this replacement procedure will involve the potential for hot coolant, be sure both the heater and motor home engine are adequately cooled.
3.
Using hose pinch off pliers, clamp both hoses attached
to the engine preheat loop, closed.
4.
Remove the Hose and hose barb fitting attached to the
engine preheat pump bulk head fitting.
5.
Using a 1 1/4” and a 1 3/8” wrench loosen and remove
the bulk head fitting.
6.
Using a 3/4” and a 1 1/8” wrench disconnect the union
securing the engine preheat pump in place.
7.
Disconnect the defective circulation pump’s wires by
removing the protective loom, and cutting both the positive and negative wires with wire cutters.
7.
Remove the zone circulation pump.
8.
Using a 1” wrench remove both of the copper pump
stands from the defective pump. Be sure to mark the
location of each stand to ensure proper installation of the
replacement pump.
9.
Wrap the threads of the new replacement pump with a
thread seal tape.
Troubleshoot the Engine Preheat Pump if the following condition has occurred:

The Engine Preheat Pump is not operating, and the
Engine Preheat Switch inside the motor Home is in the
ON position .
Troubleshooting:
NOTE: Either the diesel-burner switch or the electric element switch must also be activated in order for the engine
preheat feature to function.
A. Using a Volt Meter , Check for voltage on the Fuse
Block for the Engine Preheat, Fuse A.
a. If No voltage, replace the fuse.
b. If Yes continue.
B. Using a Volt Meter , Check for a Ground signal on
the Terminal Strip for the Engine Preheat Pump.
a. If No ground is present use a jumper wire and
jumper the engine preheat connection on the
terminal strip to a ground. If the Engine Preheat
pump comes on and runs check for loose wires.
If no loose wires are present replace the engine
preheat switch inside the motor home
If Yes continue.
C. Check the Engine Preheat pump for voltage.
a. If there is voltage and the engine preheat
pump is not operating, follow the engine pre
heat pump replacement procedure in this book.
NOTE: Before Replacing the Pump Remove and inspect
the brushes on the pump. If they are less than 1/8” the
brushes are to worn and will prevent the pump from
operating.
10. Install the pump stands onto the replacement pump, and
tighten down with a 1” wrench.
11. Reinstall the engine preheat pump. Be sure the arrow on
the pump is pointing towards the aqua hot boiler tank.
NOTE: The engine preheat pump can be tested by connecting it to an external 12 Volt-DC power source to verify
that the pump is defective.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 5: AQUA-HOT COMPONENTS
12. Reinstall the bulk head fitting. Be sure to use a back up
wrench on the pump stand to ensure the pump is properly
positioned while tightening down the bulk head fitting.
16. Remove the hose pinch off pliers previously used to pinch
off the hose.
17. Test for proper operation
13. Using a 3/4” and a 1 1/8 wrench tighten down the union.
14. Reconnect the hose barb fitting and hose to the engine
preheat pump bulk head fitting.
15. Reconnect the wires on the replacement pump to the wire
harness on the heater by using a red butt connector. Be
sure to review the wiring schematic in appendix A for
proper pump wiring.
NOTE: The Aqua Hot Engine Preheat pump is not a self
priming pump. If the pump gets an air pocket, it will be
necessary to bleed the air out of the pump. To bleed the air
out of the engine preheat pump it may be necessary to turn
on the motor home’s engine and let it run for approximately
10 minutes.
Figure 17
Union
Pump
Bulkhead
fitting
Bulkhead
Fitting
Locking nut
Pump
Stand
Pump
Stand
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 28 —
SECTION 5: AQUA-HOT COMPONENTS
Zone Relay:
Zone Pumps
Interior Heat Exchanger Fans/
The Zone relay is an electrical device where the DC circuit
from the Interior Room Thermostat determines whether the
DC power is permitted to flow to the circulation pump and
the heat exchanger fans. This allows the Interior Room
Thermostat to switch both the fans and circulation pump on.
Troubleshoot the Zone relay if either of the following conditions have occurred:


The Interior fans fail to operate.
The circulation pump fails to operate
Troubleshooting:
If the Interior
heat exchanger Fans fail to operate:
3. Locate the Fuse block, and using a volt meter, check for
12VDC on the C (Pumps) & D (Fans) Fuse.
If no power is present check the fuse.
4. On the Right-Hand side of the Zone relay check pins A, 7,
and 9 for 12 VDC +
If no power is present: Inspect the wires and verify
the C and D fuses are good.
5. On the Zone Relay check pin B for ground.
If there is not a ground present, verify that the room
thermostat is calling for heat, and that it is sending a
ground signal to the relay.
6. On the Left Hand Side of the zone relay, check pin 4
(Fans) or pin 6 (pumps) for 12 VDC +.
If no power is present replace the Zone Relay.
1.
Turn the corresponding room thermostat on, on the interior of the motor home, ensuring the thermostat is set at
the maximum heat setting, to ensure they will call for
heat.
NOTE: If the new zone relay does not fix the problem, it is
possible the relay socket has gone bad. The relay socket can
be removed by pulling on the release tab on the right hand
side of the relay socket
2.
Using a Digital Volt meter, verify that the room
thermostat has sent a ground signal to the terminal strip
for the corresponding zone.
Replacement Procedure:
If there is no ground signal from the interior room
thermostat inspect the wire going to the room
thermostat. If the wire is good, replace the interior room
NOTE: If there is no ground for pin 0, it is possible to bypass the motor homes’ interior room thermostat by supplying an external ground to the terminal block for the particular zone being trouble shot. If the zone works with the interior room thermostat bypassed the problem is located in the
motor home, not within the heating system.
1.
Release the clip securing the relay in place.
2.
Pull the relay out of the relay socket.
3.
Install the replacement relay into the relay socket.
4.
Secure the relay in place with the relay clip.
Figure 18
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 5: AQUA-HOT COMPONENTS
Bedroom Zone
Bathroom Zone
Living room Zone
Terminal Strip
Figure 19
Fuse Block
A B
C
D
E
F
Relay Socket
Relay
Relay Clip
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 30 —
SECTION 5: AQUA-HOT COMPONENTS
Electrical - AC
3.
Electric Heating Element:
A. Remove the AC access cover.
The electric heating element uses AC power as an alternate
power source for heating the Aqua-Hot’s boiler tank.
Troubleshoot the electric heating element if the following
condition has occurred:

B. Using an AC voltmeter, verify that 110 volts of AC
power are present.
4.
There is a lack of hot domestic water and interior heat
when the electric element is selected as the heating
source.
1.
2.
5.
Verify that the motor home is either plugged into shore
power or that the generator is running to provide AC
power.
Check the electric heating element for functionality by
completing the following:
A. Disconnect all power supplies.
B. Remove all wires from the electric heating element.
Verify that the “Electric” Switch is on, inside the motor
home.
Note: This Model of Aqua Hot may not have a switch for
the electric element. If no switch is found verify the A.C.
Breaker for the Aqua Hot is in the On Position. If there is a
12 VDC switch activating a 120 VAC heating element there
is a relay that is triggered by the 12 VDC switch, which then
will activate and allow A.C. Power to the Aqua Hot.
If Adequate AC power is present at the Aqua-Hot Check
The following:
A. Using a digital Clamp-On amp-meter, verify that
11.2 to 13 amps are present the element’s wires. If
the Electric Element wires show a 11.2 - 13 amp
draw the electric element is working properly
Troubleshooting:
NOTE: For continuous domestic hot water to be present, the
diesel-burner must be selected also as a heating
source.
Verify that the electric heating element is receiving adequate AC power by completing the following:
C. Using an ohmmeter, check the electric heating element for the proper ohms reading (8-9 ohms). If the
proper ohms reading is not read, follow the instructions in this manual for replacing the electric heating element.
NOTE: Follow the Troubleshooting guide for both the control and overheat thermostats before replacing the Electric
Element.
If the Electric Switch\ A.C Breaker is on, and operating
properly:
A. Check the temperature of the Aqua-Hot’s boiler
tank.
If the boiler tank temperature is below 185°F, troubleshoot the control thermostat for the electric element.
If the boiler tank is above 210°F, the Aqua-Hot is at
operating temperature and requires no heat.
Replacement Procedure:
FAILURE TO DISCONNECT ALL POWER SUPPLIES AND/OR
TO ALLOW THE HEATER TO COOL BEFORE SERVICING
COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY.
1.
Ensure that the Aqua-Hot has been completely shut
down and that all power sources have been disconnected. Also, because this replacement procedure will involve the boiler tank and the potential for hot coolant, be
sure the heater has adequately cooled.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 31 —
SECTION 5: AQUA-HOT COMPONENTS
2.
Drain the antifreeze and water heating solution from the
Aqua-Hot’s boiler tank using the drain valve.
3.
Remove the Electric Element access cover.
4.
Remove the two wires secured to the defective electric
heating element by releasing the screw terminals.
Using a 1-1/2 inch socket, remove the defective electric
heating element from the Aqua-Hot boiler tank.
10. Test for proper operation
5.
6.
7.
Connect the wires removed from the defective electric
heating element to the replacement electric heating element and tighten the screw terminals.
8.
Reinstall the Electric Element access cover.
9.
Refill the Aqua-Hot’s boiler tank with the antifreeze and
water heating solution.
Install the replacement 1650-watt electric heating element into the boiler tank ensuring that the “up” lettering
on the element is installed in the up position.
Figure 20
Thermostats
VAC Access
Panel
Electric Element
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 32 —
SECTION 6: DIESEL-BURNER OVERVIEW
Diesel-Burner Overview
The Aqua-Hot’s diesel-burner is a device that ignites a mixture of diesel fuel and air within a controlled setting to serve
as a heat source. The flame is established in a combustion
chamber within the Aqua-Hot’s boiler tank, and the heat
from the flame is transferred to the antifreeze and water heating solution where it can be used for each system of the Aqua-Hot - domestic hot water, interior heat, and engine preheat.
Figure 21
Diode Wire
Figure 22
Ignition Coil
Electrode
Adjustment
Gauge
Controller
Fuel Solenoid
Flame Sensor
Fuel Nozzle
Fuel Pump
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 33 —
SECTION 6: DIESEL-BURNER OVERVIEW
Figure 23
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 34 —
SECTION 6: DIESEL-BURNER OVERVIEW
Operational Flow-Chart
Operation sequence once the Aqua-Hot’s Diesel switch is turned
ON
NOTE:
The Diesel switch’s indicator
light will illuminate anytime the
Diesel Burner switch is in the ON
position
The Motor (#2), which turns the
Combustion Air Blower (#5)
and drives the Fuel Pump (#14),
will begin to operate.
NOTE:
If the Aqua-Hot’s coolant temperature is approximately 200°F (+/5°F) or higher, the Motor (#2)
will not operate. Only when the
coolant temperature has dropped
below 175(+/-5)°F, and the VDC
Control Thermostat is calling for
heat, will the Motor (#2) begin to
operate.
After approximately 10-25 seconds, the Fuel Solenoid Valve
(#6) opens and fuel is sprayed
into the Combustion Chamber
(#11) through the Fuel Nozzle
(#9)
Once the ignited air-fuel mixture
(FLAME) is observed by the
Flame Sensor (#13) the Ignition
Coil (#3) will automatically
switch OFF. The combustion
process now continues to operate
unassisted.
Once the heater switches OFF,
thermostatically or manually, the
Fuel Solenoid Valve (#6) closes,
which interrupts the supply of diesel fuel to the Fuel Nozzle (#9)
The Motor (#2) will continue to run
for approximately three (3) additional minutes. This process is referred to as the Purge-Cycle, which
cools the heater’s internal components and purges the Combustion
Chamber (#11) of any residual
exhaust gases.
NOTE:
The combustion process will continue to operate in this manner
until one of the following occurs:
A.) The VDC Control
Thermostat, which senses coolant temperature, reaches the preset temperature of approximately
200 (+/-5)° F.
B.) the Aqua-Hot Diesel Burner
Switch is turned OFF.
When the Aqua-Hot’s Diesel Burner is switched OFF by the
VDCControl Thermostat, the following process will take place:
1.
The Motor (#2) will shut off
once the three (3) minute
Purge-Cycle has expired.
-THEN2. The Aqua-Hot’s Diesel Burner
will automatically turn back ON
once the coolant reaches the preset
temperature of approximately 200
(+/-5) °F
NOTE:
If process “B” occurs, the Diesel
Burner switch’s Indicator
Light, on the Switch Panel will
go OFF.
After approximately 10-25 seconds, the Fuel Solenoid Valve
(#6) opens and fuel is sprayed
into the Combustion Chamber
(#11) through the Fuel Nozzle
(#9)
Summary:
The Aqua-Hot’s Diesel-Burner is
operational anytime the operator
moves the Diesel Burner Switch to
the ON position. The DieselBurner will then automatically
maintain the coolant temperature in
the Aqua-Hot Boiler Tank without
additional involvement from the
operator.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 35 —
SECTION 6: DIESEL-BURNER OVERVIEW
Diesel-Burner Operations:
The following sequence illustrates how the Diesel-Burner
operates once it is activated. Also, if diesel-burner malfunctions are experienced, use this sequence of operating events
as a diagnostic tool to determine at what point in the dieselburner’s operation the malfunction is occurring. Use the
“KEY” provided to understand each symbol shown.
Figure 24
NOTE: The Motor and Combustion Air Blower will begin to operate only if the VDC Control Thermostat is closed and calling for heat
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 36 —
SECTION 6: DIESEL-BURNER OVERVIEW
Figure 25
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 37 —
SECTION 6: DIESEL-BURNER OVERVIEW
Figure 26
The Diesel-Burner will continue to produce heat in this manner until it is
switched off either manually or by the VDC Control Thermostat, which occurs when the coolant temperature in the Aqua Hot’s Boiler Tank Reaches
200 (+/- 5) degrees Fahrenheit.
NOTE: Whenever the Diesel-Burner is switched off by the VDC Control Thermostat, it will automatically be reactivated once the Aqua-Hot
Boiler Tank’s coolant reaches the preset termperature of approximately
175 (+/-) 5 degrees Fahrenheit.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 38 —
SECTION 7: DETACHING
AND
REATTACHING
THE
DIESEL BURNER
Instructions for Detaching the Diesel Burner
WARNING!
Be sure to move the Diesel-Burner switch on the Interior Switch Panel to the OFF position and disconnect the
Diesel-Burner’s power supply before detaching the Diesel-Burner from the Aqua-Hot. Failure to turn off the
Diesel-Burner and disconnect power could result in serious bodily injury.
CAUTION!
Be sure to clamp off the Fuel Supply and Return lines at the ports on top of the Aqua-Hot prior to beginning this
replacement procedure.
Step 1: Turn Off the Diesel Switch
Figure 27
1. Move the Interior Switch Panel’s Diesel-Burner switch to the “OFF” position.
Step 2: Remove the Access Cover
Figure 28
1. Remove the Aqua-Hot’s access cover by locating
the screws securing it in place.
2. Unscrew the screws securing the cover in place.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 39 —
SECTION 7: DETACHING
AND
REATTACHING
THE
DIESEL BURNER
Step 3: Disconnect the Diesel Burner’s Controller
Figure 29
B-Plug C-Plug
1. Locate the Diesel-Burner’s Controller and disconnect both plugs.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 40 —
SECTION 7: DETACHING
AND
REATTACHING
THE
DIESEL BURNER
Step 4: Remove the Diesel Burner from the Aqua-Hot
Figure 30a
Figure 30b
1. The Diesel-Burner is secured to the Aqua-Hot with two nuts that can be loosened,
and swung out of the way by using a 10mm socket wrench with a 10 inch long extension.
Figure 30c
2. Carefully pull the Diesel-Burner away from the Aqua-Hot 4 to 5 inches before
rotating the burner, and then remove.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 41 —
SECTION 7: DETACHING
AND
REATTACHING
THE
DIESEL BURNER
Step 5: Disconnect the Diesel Burner’s Thermostat Wires From the Aqua-Hot
Figure 31b
Figure 31a
Thermostat
Access Cover
Wire Access
Slot
1. Using a Phillips head Screw Driver loosen the screws
securing the thermostat access cover in place, and remove
the thermostat access cover.
1. Disconnect the thermostat wires by firmly
pulling on the pink connectors. Remove the
wires from the wire access slot.
Step 6: Disconnect the Fuel Lines From the Diesel Burner
NOTE: Before Disconnecting the fuel lines, it is recommended to use hose pinch off pliers on the rubber fuel lines, to shut the flow
of fuel off, while the burner is removed.
Figure 32
1.
2.
Using Pliers loosen the constant tension clamps securing the fuel lines to the diesel burner, and slide away from the burner.
Remove the fuel lines from the diesel burner.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 42 —
SECTION 7: DETACHING
AND
REATTACHING
THE
DIESEL BURNER
Reattaching the Diesel Burner to the Aqua-Hot
CAUTION!
When reattaching the diesel-burner be sure to properly align the diesel-burner before tightening the eye-bolt nuts. Also, visually
inspect all of the rubber grommets on the top and bottom of the diesel-burner’s cast-aluminum blower casing to ensure they are in
place. DO NOT over tighten the eye-bolt nuts. Torque specifications are: approx. 20-40 in. lbs. An improper alignment and/or
over tightening of the eye-bolt nuts can cause damage to the diesel-burner’s cast aluminum blower casing.
Step 1: Reattach the Fuel Lines to the Diesel Burner
Figure 33
1. Install the fuel lines onto the fuel pipe banjo fittings.
2. Using pliers loosen, and slide the constant tension clamps back into place, to secure the fuel lines.
3. Remove the hose pinch off pliers.
CAUTION!
The Aqua Hot is equipped with a fuel supply check valve. If the fuel lines are hooked up backwards on the burner. Serious damage
may occur to the diesel burner fuel pump.
Step 2: Reattach the Diesel Burner to the Aqua Hot
Figure 34a
Figure 34b
1. Install the burner on the Aqua Hot and swing the eye bolts over the mounting tabs on the diesel
burner. The eye-bolt nuts can then be tightened by using a 10mm socket wrench with a 10 inch long
extension. Use extreme caution when tightening down the eye-bolt nuts, over tightening of the eyebolt nuts can cause the aluminum blower casing to crack.
(Torque Specifications = Approximately 20-40 in. lbs.)
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 43 —
SECTION 7: DETACHING
AND
REATTACHING
THE
DIESEL BURNER
Step 3: Plug in the diesel-burner’s controller and mount
3. Locate the Diesel-Burner’s Controller and connect both plugs.
Figure 35
NOTE: The Diesel Burner’s Controller might have to be mounted onto the side of the diesel burner, before the
plugs are inserted into the control unit, otherwise it might not be possible to mount the control unit.
Step 4: Reinstall the Access Cover
Figure 36
1. Reinstall the Aqua-Hot’s access cover .
2. Securely tighten the screws securing the access
cover in place.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 44 —
SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
1.
2.
Is the indicator
light illuminated?
Turn the Control
Switch ON.
NO
3.
4.
5.
1.
2.
Yes
Remove the AquaHot’s Access cover.
Check the AquaHot fuse (F) for
continuity. Replace
if necessary.
1.
NOTE: The Indicator
light will illuminate for
only 30 seconds if fuse
(F) is blown (open
circuit)
3. Attempt heater restart
NO
Is the Diesel Burner’s “MOTOR”
operating?
2.
Yes
3.
Remove the Aqua-Hot’s Access
Cover
Remove the “Thermostat Access
Panel”
Check the Diesel Burner’s “VDC
High-Limit Thermostat” for continuity
NOTE: This thermostat protects
against overheating temperatures.
Check the Diesel Burner’s
“VDC Control Thermostat” for continuity.
1.
Check indicator light bulb. Replace if necessary.
Remove the Aqua-Hot’s ACCESS
COVER.
Check Aqua-Hot fuses (E & F) for
continuity.
Check DC power supply at the
“Power Post” and “Ground Post”.
Attempt heater restart.
Is there continuity
across the
thermostat?
Yes
NO
Replace Thermostat.
NOTE: Aqua-Hot operating temperature must be
below 175ºF when checking
the “VDC Control Thermostat” for continuity.
NO
Is there continuity
across the
thermostat?
1. Replace the Thermostat.
2. Attempt Heater Restart
2. Attempt Heater Restart
Yes
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 45 —
SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
1.
2.
Turn the Control Switch Off.
Remove the fuel-line from the AquaHot’s “Diesel Fuel Return” and place
a short piece of fuel line in its place.
Put the opposite end of the fuel line in
a container.
Place the probes of a DC Multi meter
into plug locations, B-1(+) and B-2(-),
of the Diesel Burner’s “Control Unit”.
Also, measure the voltage across
B-2 (-) and B-4 (+)
Turn the Control Switch ON.
Observe the fuel flow. Flow should
be consistent without air bubbles.
3.
4.
5.
6.
1.
Is the fuel flow
consistent without air bubbles?
2.
NO
3.
4.
Yes
1.
1.
Check the voltage level of
the DC-multi meter.
NOTE: Voltage level should be
within 0.5 volts of the system’s
DC batter voltage.
Check for fuel leaks in
the Diesel Burner’s
“Diesel Fuel Supply”
line. Repair if necessary.
Check the Aqua-Hot’s
“Fuel Filter” for clogging.
Replace if necessary.
Reattach “Diesel Fuel
Return” line.
Attempt heater restart.
Does the DC multi
meter indicate acceptable system
voltage?
2.
NO
3.
4.
Check the Control
Switch’s:
A. Wire connections
B. Fuse (E) for
continuity.
Check DC power supply
wires and connections.
Reattach “Diesel Fuel
Return” line.
Attempt heater restart.
Yes
1.
2.
3.
Inspect eh “Flame Detection
Photocell” for dust and/or
sooty carbon deposits. Clean if
necessary.
Completely cover the “Flame
Detection Photocell” with a
shop rag.
Turn the Control Switch ON.
After approx. 20 seconds of
operation a bright blue arc
(spark) should appear across
the “Ignition Electrodes”.
1.
2.
3.
4.
Turn the Control Switch OFF.
Reattach “Diesel Fuel Return” line.
Detach the “Diesel-Burner Head” from the Aqua Hot.
Disconnect one of the wires from the “Fuel Solenoid Valve”
NOTE: Do not remove or cut any of the external wires attached to
the “Diesel Burner Head”.
1.
2.
Do not attempt to restart the Aqua Hot when the “Diesel Burner Head” is detached. An open flame can result and cause serious personal injury.
To prevent a fire hazard, be ure to disconnect one of the “Fuel
Solenoid Valve” wires.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 46 —
SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Does a spark
appear across the
Ignition Electrodes?
Within 15 seconds, after turning
ON the Control Switch, disconnect
one of the two wires from the
“Flame Detection Photocell”. A
spark should now appear across the
“Ignition Electrodes”.
NO
Does a spark
appear across the
Ignition Electrodes?
Yes
Yes
1.
2.
Remove shop rag from the “Flame Detection Photocell, exposing it to a light
source. The spark should disappear.
NO
Turn the Control Switch OFF.
Check “Flame Detection Photocell” for
proper operation by: Removing both
wires from the Photocell and covering
with a shop rag. When dark, Photocell
wire leads should read 300,000 ohms, or
greater, of electrical resistance. Remove
shop rag and expose to light; electrical
resistance should be 300 ohms or less.
1.
2.
Does a spark
disappear after
the Photocell is
exposed to
Yes
Does the Photocell
operate Properly?
1.
2.
3.
Replace the “Flame Detection
Photocell.
Reconnect “Fuel Solenoid
Valve”.
Reattach “Diesel Burner Head”
and attempt heater restart.
1.
2.
3.
Cover “Flame Detection Photocell”
again with a shop rag. The spark
should reappear and continue for
approx. 15 seconds and then switch
off.
1.
2.
3.
Replace “Control Unit”.
Reconnect “Flame Detection
Photocell” wires and “Fuel Solenoid Valve” wire.
Reattach “Diesel Burner Head”
and attempt heater restart.
Replace “Control Unit”.
Reconnect “Flame Detection
Photocell wires, “Fuel Solenoid
Valve” wire and C-plug.
Reattach “Diesel Burner Head”
and attempt heater restart.
NO
Does the Ignition
Coil operate
Properly?
NO
Yes
Turn the Control
Switch OFF.
Check “Ignition Coil”
for proper operation by:
Removing C-plug from
“Control Unit”. Apply
DC power (+) to C-8
plug (yellow wire) and
ground (-) to C-5 plug
(brown wire). A spark
should now appear
across the “Ignition
electrodes”.
Yes
NO
1.
2.
3.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
Replace “Ignition Coil”.
Reconnect “Flame Detection Photocell” wire,
“Fuel Solenoid Valve”
wire and C-plug.
Reattach “Diesel Burner
Head” and attempt heater
restart.
— Page 47 —
SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
1.
2.
3.
Does the spark
reappear?
Yes
To prevent a HIGH VOLTAGE shock and or a fire hazard, be sure to
remove both “Ignition Electrodes” (tape the ends and separate the
wires) or connect a jumper wire across the Electrodes.
NO
1.
2.
3.
4.
Turn the Control Switch Off.
Replace the “Control Unit”.
Reconnect “Fuel Solenoid Valve” wire.
Reattach “Diesel Burner Head” and attempt
heater restart..
1.
2.
3.
4.
5.
6.
Turn the Control Switch OFF.
Reconnect “Fuel Solenoid Valve” wire.
Remove both ignition wires from the “Ignition Electrodes” or
connect a jumper wire across the Electrodes.
4. Turn the Control Switch ON. After approx 20 seconds the “Fuel
Solenoid Valve” should receive power from the “Control Unit”. A
fine mist of fuel should appear from the “Fuel Nozzle”.
Replace “Fuel Solenoid Valve”.
Retest fuel flow (without Fuel Nozzle).
Install “Fuel Nozzle”.
Retest Fuel Nozzle spray pattern (fine mist
of fuel present?).
Reconnect Ignition wires to “Ignition Electrodes” or remove jumper wire.
Reattach “Diesel Burner Head” and attempt
heater restart.
Is a mist of fuel
(Cone-Shaped)
present?
Yes
1.
2.
3.
Turn the Control Switch Off.
Reconnect ignition wires to
“Ignition Electrodes” or remove jumper wire.
Reattach “Diesel Burner
Head” and attempt heater
restart.
NO
1.
2.
3.
Turn the Control Switch Off.
Remove “Fuel Nozzle”.
Turn the Control Switch ON.
After approx. 20 seconds fuel
should flow freely from the
fuel nozzle port.
NO
1.
2.
Does the Solenoid
Valve operate
properly (click)?
Turn the Control Switch
OFF.
Check “Fuel Solenoid
Valve” for proper operation
by: Removing both wires
from the Solenoid Valve and
applying VDC Power (+) and
ground (-) to the Solenoid
Valve electrical terminals.
“Fuel Solenoid Valve”
should click when VDC
power is applied.
NO
Does fuel flow
freely from the
port?
NO
Yes
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
Yes
— Page 48 —
SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
1.
2.
3.
4.
5.
6.
Check “Fuel Solenoid Valve”
wires for continuity. Replace
wires if necessary.
Replace “Control Unit” if wires
indicate continuity.
Retest fuel flow (without Fuel
Nozzle)
Install “Fuel Nozzle”.
Retest Fuel Nozzle spray pattern
(fine mist of fuel present?).
Reattach “Diesel Burner Head”
and attempt heater restart.
1.
2.
3.
4.
5.
Turn the Control Switch OFF.
Replace “Fuel Nozzle”.
Retest Fuel Nozzle spray pattern
(fine mist of fuel present?).
Reconnect ignition wires to
“Ignition Electrodes” or remove
jumper wires.
Reattach “Diesel Burner Head”
and attempt heater restart.
NOTE: If an improper fuel spray is still observed (a normal spray
pattern should be observed as a coned-shaped mist) the Diesel
Burner’s “Fuel Pump” should be calibrated for the proper fuel
pressure setting.
End of Troubleshooting Flow Chart.
For additional troubleshooting information please contact:
Aqua Hot Heating System’s Service Department
at 303-659-8221
Mon-Fri
7:00 a.m. - 4:00 p.m.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 49 —
SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Diesel-Burner Motor:
The motor drives the combustion air blower and the
fuel pump. In order to perform the following procedures, it may be necessary to detach the dieselburner head.
NOTE: Before testing the diesel burner motor it is recommended to ensure that the ground post on the Aqua-Hot is
securely tightened.
Turn the diesel switch ON and verify both the
diesel burner switch (B1) and the diesel burner
motor (B4) have 12VDC.
NOTE: If the B1 Terminal does not have power verify that
the E-Fuse is good, and that the diesel burner switch is sending power to the diesel burner controller.
If the B4 Terminal does not have power verify that the FFuse is good.
2.
Locate the diesel-burner controller’s C-Plug and
insert the probes of a DC voltmeter into the C-2 (+)
and the C-5 (-) locations.
If normal voltage is present inspect the C-Plug Harness
for loose or damaged wire connections. If the C-Plug
harness and connections are in good condition, but the
motor is not operating the motor must be replaced.
If there is no 12 Volts D.C. present on the C-2 pin,
The diesel burner controller will need to be replaced.
Component Test:
1.
3.
NOTE: Before replacing the diesel burner controller it is
recommended to test the motor seperately to ensure that it is
not defective. It is possible for a bad motor to cause the C2
Pin to not have 12 volts D.C.
Figure 37
Verify that the control thermostat is calling for heat,
which it should be when the boiler antifreeze
temperature is below 175 ºF.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 50 —
SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Diesel-Burner Motor (continued) -
RPM Test:
1.
Disconnect the ignition cables from the ignition
electrodes.
7.
Connect the motor’s wires directly to a 12 volt DC
power supply.
2.
Remove the four ignition coil screws that secure the
ignition coil to the protection cap.
8.
Turn the power supply ON and use a phototachometer to test for a proper RPM reading.
3.
Lift the ignition coil and disconnect its wires from
the C-Plug harness wires prior to removing.
9.
4.
Remove the protection cap from the diesel-burner
so that the motor and clutch halves are exposed.
At approximately 12 volts DC the RPM reading
should be 4500 RPM’s (+/- 300 RPM’s.) If the
motor’s RPM reading is not within the above specs,
the motor must be replaced.
NOTE: It may be necessary to remove the diesel-burner to
remove the bottom two screws securing the protection cap in
place. Follow the direction on detaching and reattaching the
diesel burner.
5.
6.
Place a few wraps of black electrical tape around
the clutch halves and then place a small piece of
reflective tape over the black tape.
NOTE: Test the diesel-burner’s bearings prior to reattaching the diesel-burner head or replacing the motor.
Worn bearings can cause lower than normal RPM
readings and premature motor wear. To properly
test for worn bearings, reference the bearings function test section.
Figure 38
Disconnect the motor’s black (+) and brown (-)
wires from the C-plug harnesses black (+) and
brown (-) wires.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 51 —
SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Motor Replacement Procedure:
Be sure to move the Diesel-Burner switch on the Interior Switch Panel to the OFF position and disconnect the Diesel-Burner’s power supply before detaching the Diesel-Burner from the Aqua-Hot. Failure to turn off the Diesel-Burner and disconnect
power could result in serious bodily injury.
5. The motor must be mounted to the flange with the
wires and drain hole pointing downward and the
recessed edge of the motor flange pointing upward.
This will ensure a proper protection cap fit.
NOTE: Be sure to test the diesel-burner’s bearings prior to
reinstalling the motor. Worn bearings can cause
lower than normal RPM readings and premature
motor wear.
6.
1.
Follow the directions for detaching the diesel burner
in section ?
2.
Remove the four ignition coil screws that secure the
ignition coil to the protection cap. Lift the ignition
coil to disconnect its wires from the C-plug harness
wires prior to removing. Remove the protection cap
from the diesel-burner so that the motor clutch
halves are exposed.
Reinstall a clutch half on both the new motor’s shaft
and the combustion air blower shaft. Attach the
motor and flange assembly, with the recessed edge
of the motor flange in-line with the wiring access
slot of the blower casing, to the blower housing
with the three hex head screws.
NOTE: Inspect the blower casing’s O-ring for damage or
wear prior to reinstalling the diesel-burner head’s
protection cap. If damage or wear exists, replace
the O-ring.
Remove the three hex head screws that secure the
motor and flange assembly to the blower housing.
Remove the motor and flange assembly along with
the clutch halves. Disconnect the motor’s black (+)
and brown (-) wires from the C-plug harness’ wires.
7.
NOTE: Inspect the clutch halves for cracks and also ensure
that the flat portion in each shaft hole is free of
wear and tear. Too much play on the shaft produces a loud clacking noise. If any cracks or wear are
detected, the clutch half must be replaced.
Connect the black (+) and the brown (-) wires of the
new motor to the C-Plug harness’ yellow (+) and
brown (-) wires. Feed the C-plug harness’ yellow
and brown wires back through wiring access hole in
the protection cap.
8.
Reinstall the protection cap. Reconnect the black
(+) and brown (-) wires.
9.
Reinstall the ignition coil and secure to the protection cap with the four ignition coil screws.
10.
Follow the directions for reattaching the diesel
burner in section ?
3.
4. Detach the motor from the motor flange by removing
the two Phillips heads screws that fasten the two
parts together.
NOTE: The new blower motor may come mounted to a new
motor flange.
11. Test for proper operation
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 52 —
SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Figure 39
Motor Replacement Procedure: (continued)
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 53 —
SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Flame Sensor:
The flame sensor is a photo resistive device which
supplies the diesel-burner’s controller with a DC
voltage signal when it detects a flame. When the
flame sensor senses the light of the flame, it will
shut the ignition coil off, and send a signal to the
diesel burner controller indicating that everything is
working properly. If the flame sensor does not
sense the flame, it will shut the diesel burner down
in a default after 20 seconds.
NOTE: In order to perform the following procedures it is
necessary to detach and reattach the diesel-burner
head. Be sure to review the detaching/attaching
instructions.
Component Test: Ohms
NOTE: Be sure to calibrate your ohmmeter prior to checking the flame sensor to proper resistance values.
1.
2.
In order to perform the following procedures it is
necessary to detach the diesel-burner. Be sure to
review the detaching/attaching instructions in section 7.
Once the diesel burner has been removed, Locate
and detach the flame sensor’s green and blue wires
from the C-plug harness wires.
3.
Connect the flame sensor’s green and blue wires to
an ohmmeter.
4.
Check resistance by placing a shop rag over the
flame sensor’s glass surface, to simulate a no flame
condition, and then remove the rag and expose to a
light source, to simulate a flame condition.
5.
If the flame sensor is operating properly, the ohmmeter should register high resistance, over 100K Ω
when the glass surface is covered, and less than 200
Ω when exposed to a light source.
6. If these resistance numbers cannot be obtained, verify the flame sensor’s glass surface is clean. If the
flame sensor is clean and the resistance numbers
cannot be obtained, the flame sensor must be replaced.
Flame Sensor Maintenance:
1.
For light dirt, dust, and/or carbon deposits, simply
wipe off the flame sensor with a soft cloth.
2.
Should heavy carbon deposits be present, completely remove the flame sensor from the photo disc and
clean with brake cleaner.
Figure 40
Flame Sensor
Green Wire
Blue Wire
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 54 —
SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Flame Sensor Replacement Procedure:
1.
In order to perform the following procedures it is
necessary to detach diesel-burner head. Be sure to
review the detaching/attaching instructions in section 7.
2.
Remove the screw that fastens the flame sensor to
the photo disc and detach the sensor’s green and
blue wires from the C-plug harness’ green and violet wires, and remove flame sensor.
3.
Slide the tab of the new flame sensor into the provided slot in the photo disc and secure in place with
the screw. Connect the flame sensor’s green wire to
the green C-plug harness wire and the blue wire to
the C-plug harness’ violet wire.
4.
Follow the directions for reattaching the diesel
burner, in section 9 of this manual.
Figure 41
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 55 —
SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Ignition Electrodes
The diesel-burner’s ignition coil produces a high
voltage ignition spark across the ignition electrodes,
which ignites the incoming air/fuel mixture.
Cleaning and Maintenance:
1.
Polish away any carbon deposits that may have
baked onto the metal tips of the ignition electrodes
with a course sponge.
2.
If the ignition electrode’s electrical insulator is
cracked or damaged, the ignition electrode must be
replaced.
NOTE: The electrode adjustment gauge is used to set the
gap between the ignition electrodes. The electrode
adjustment gauge is located on the outside surface
of the diesel-burner head on the left hand side.
Ignition Electrode Adjustment Procedure:
1.
Follow the directions for detaching/reattaching the
diesel burner in section 7 Of this manual.
2. Using a 10mm socket, slightly loosen the retaining
clamp bolt.
3. Place the electrode adjustment gauge on the nozzle
manifold hex and insert the metal tips of the ignition
electrodes into the appropriate notches of the electrode adjustment gauge.
NOTE: Be sure not to over-tighten the retaining clamp bolt
when readjusting the ignition electrodes. Overtightening the retaining clamp bolt will bend the
retaining clamp and prevent the photo disc from
floating freely. Not allowing the photo disc to float
freely will cause poor combustion and result in a
smoky exhaust. A bent retaining clamp can be restraightened with a punch and hammer. Lay the
clamp’s beveled side down on a solid flat surface
and align the thick end of the punch at dead center.
Tap the punch lightly until the retaining clamp returns to proper form.
4.
Using a 10 mm socket, tighten the retaining clamp
bolt.
5. Remove the electrode adjustment gauge and reattach to the diesel-burner head.
Replacement Procedure:
1. Using a 10mm socket, loosen and remove the retaining clamp bolt, and the retaining clamp.
2.
Slide the electrode out of the photo disc.
3.
To remove the electrode, hold onto the orange electrode boot, and pull firmly on the electrode.
4. Once the electrode has been removed Inspect inside
the orange electrode boot for the retaining clip,
which holds the electrode in place. If it is missing,
replace the electrode boot.
Figure 42
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SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Ignition Electrodes
2.
Replacement Procedure: (continued)
5. Insert the new electrode into the orange electrode
boot, and snap into place. Pull firmly on the electrode to make sure the retaining clip has secured the
electrode in place.
Remove both the ignition cables from the ignition
electrodes, or connect a jumper wire (with alligator
clips) across the metal tips of the electrodes.
Failure to connect a jumper wire across the ignition electrodes, or to remove the ignition cables from the ignition
electrodes will result in a HIGH VOLTAGE shock and/
or a fire. If the ignition cables are removed, be sure to
place a piece of electrical tape on the end of each cable.
6.
Slide the electrode into the photo disc.
7.
Install retaining clamp and retaining clamp bolt and
finger tighten.
3.
Remove the B-plug from the diesel-burner head’s
controller.
8.
Follow steps 2 - 5 to properly adjust the electrodes.
4.
Turn the diesel switch ON and then plug the B-plug
back into the diesel-burner controller to activate the
diesel-burner. After approx. 20 seconds the fuel
solenoid will “click” and a fine mist of fuel should
appear from the fuel nozzle in a cone shaped spray
pattern.
Fuel Nozzle:
The fuel nozzle is simply a fuel atomizer. It reduces
the diesel fuel into a fine spray which is mixed with
incoming combustion air and is ignited within the
combustion chamber.
Figure 43
NOTE: In order to perform the following procedures it is
necessary to detach and reattach the diesel-burner
head. Be sure to review section 7 for detaching and
reattaching instructions.
Fuel Nozzle Component Test:
1. Follow the directions for detaching the diesel burner,
in section 7, of this manual.
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SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Fuel Nozzle:
2.
5.
Remove the B-plug from the diesel-burner controller.
6.
If the cone shaped spray pattern did not appear, fol
low the troubleshooting guides for the following
components and verify they are operating properly:
A. Fuel Solenoid
B. Fuel pump
C. D.C. High Limit thermostats
NOTE: An adjustment of the ignition electrodes may be
necessary after replacing the fuel nozzle. Follow
the ignition electrode adjustment procedure found
in the ignition electrode section of this manual.
3.
7. If the components listed above are operating properly, and there is still no fuel coming out of the nozzle,
replace the fuel nozzle.
Fuel Nozzle Cleaning and Maintenance:
The fuel nozzle is a precision calibrated part and
cannot be cleaned or serviced. A replacement
of the fuel nozzle is recommended annually.
Use a 3/4 in. wrench to hold the fuel nozzle stand
hex while loosening the fuel nozzle with a 5/8 in.
wrench and remove.
After replacing the fuel nozzle, reattach the dieselburner head.
Be sure to reattach the diesel-burner head prior to
switching the heater ON. Failure to do so may result in
ignition of the diesel-burner and serious bodily injury.
4.
Turn ON the diesel switch for 5 seconds, then turn
it OFF. This will activate the diesel-burner’s
prime-cycle and flush the fuel system of any potential contaminants. Perform this procedure twice.
5.
Test for normal operation.
Fuel Nozzle Replacement Procedure:
1.
When replacing the fuel nozzle, be sure to tighten
the nozzle, loosen it a 1/4 turn, and then firmly retighten. This will establish a seated fit and avoid
any leaks.
NOTE: Be sure to use care when handling the new fuel
nozzle. Oils and/or small dust or dirt particles from
your hands may plug the nozzle’s small orifice. A
partially plugged orifice will restrict fuel flow,
which will affect the combustion process of the
diesel-burner.
Figure 44
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SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
stand approximately 1/2”. Remove the fuel solenoid shaft from the nozzle manifold using a 16mm
wrench.. Discard the shaft and valve kit, as replacements are provided with the new fuel solenoid assembly.
Fuel Solenoid:
The fuel solenoid allows the flow of diesel fuel to
the diesel-burner’s fuel nozzle.
NOTE: If a long after-smoking condition exists during the
diesel-burner’s purge cycle, the fuel solenoid valve
kit may need to be replaced.
NOTE: In order to perform the following procedures it is
necessary to detach and reattach the diesel-burner
head. Be sure to review the detaching/attaching
instructions.
Fuel Solenoid Component Test:
NOTE: If the fuel solenoid is not working troubleshoot the
diesel burner’s hi-limit thermostats. If they are tripped they
will not allow the fuel solenoid to operate.
1.
Locate and detach the C-plug harness’ violet (+)
and Brown (-) wires from the fuel solenoid.
2.
Connect the (-) lead of a 12 volt DC power supply
to the fuel solenoid’s (-) electrical terminal.
3.
Intermittently apply the (+) lead of the power supply to the fuel solenoid’s (+) electrical terminal.
4.
Listen for the fuel solenoid to click (i.e. open and
close).
5.
If the fuel solenoid does not click, it must be replaced.
3.
Insert the contents of the new fuel solenoid valve kit
into the new fuel solenoid shaft. Slide the new fuel
solenoid onto the fuel solenoid shaft. Thread the
new fuel solenoid shaft with fuel solenoid to the
fuel nozzle manifold and tighten. Secure the fuel
solenoid in place with the new flat washer and lock
nut.
4.
Connect the C-plug harness’ violet (+) and brown () wires to the fuel solenoid’s (+) and (-) electrical
terminals.
Figure 45
Fuel Solenoid Replacement Procedure:
1.
Disconnect the C-plug harness’ violet (+) and
brown (-) wires from the fuel solenoid.
2.
Using an 8mm wrench, remove the lock nut and flat
washer from the end of the fuel solenoid shaft and
then pull the fuel solenoid away from the nozzle
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SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Fuel Pump:
The fuel pump draws diesel fuel from the vehicle’s
fuel tank and creates a preset pressure of 145 PSI,
which is required for proper fuel atomization. Reference the illustration below for a basic overview
and understanding of how the fuel pump functions.
7. If fuel does flow through the fuel pump when ran
off an external source inspect the following in the
motor home:
A. Check the motor home fuel tank for fuel. If the
fuel level is below 1/4 the Aqua-Hot diesel
burner will not operate.
Fuel Pump Testing Procedure:
Do not remove the diesel burner at this time. Failure to
do so may result in serious bodily injury.
1.
Clamp off and remove the fuel return and fuel supply lines coming into the Aqua-Hot unit.
2.
Attach a short piece of fuel line to both the fuel return and fuel supply ports.
3.
Submerse the opposite end of the temporary fuel
supply line in a container of diesel fuel.
4.
Place the opposite end of the temporary fuel return
line in an empty container.
5.
Turn the diesel switch ON to activate the dieselburner, and wait ten seconds.
6.
If fuel does not flow out of the return line into the
empty container, the fuel pump must be replaced.
NOTE: Prior to replacing the fuel pump, be sure to inspect
the screen filter in the supply inlet of the fuel pump
for dirt particles. Clean and/or replace if necessary.
A plugged screen filter will restrict fuel from entering the fuel pump.
B.
Inspect the supply fuel line for kinks which
would prohibit fuel flow.
C.
Inspect the supply fuel line for cuts, which
would cause the diesel burner to suck air.
D. Inspect the fuel filter, to make sure all fittings
are tight, including hose clamps. Also, make
sure the fuel filter is tight.
E.
Inspect the Aqua-Hot for loose or cracked
fittings.
F. Inspect the supply fuel system for loose hose
clamps throughout
G. Inspect the fuel pick-up tube in the tank., for
loose connection and pin holes in the pick-up
tube
Fuel Pump Cleaning and Maintenance:
1.
Check all fuel connections for tightness.
2.
Check the screen filter located in the fuel supply
inlet of the fuel pump for dirt particles. Clean and/
or replace if necessary.
3.
To adjust the fuel pressure refer to Appendix C:
Fuel pressure check and adjustment..
Figure 51
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SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Fuel Pump Replacement Procedure:
NOTE: To perform the following procedure it will be necessary to remove the diesel burner. Follow the section on
detaching and reattaching the diesel burner, section 7 of this
manual.
1.
2.
3.
4.
5.
6.
Locate and disconnect the C-Plug harness wires that
connect to the flame sensor and the fuel solenoid.
Also, disconnect the ignition cables from the ignition electrodes.
Remove the retaining clip that secures the photo
disc in place. Gently lift the photo disc so that it
releases from the nozzle stand and the ignition electrodes.
Loosen the supply and return banjo bolts to remove
the fuel supply and return pipes from the fuel pump.
Also, disconnect the high pressure fuel pipe from
both the fuel pump and the nozzle stand. Discard
the high pressure fuel pipe, gasket rings, and banjo
bolts , as replacements are provided in the new fuel
pump kit.
Remove the four nozzle stand plate screws that secure the nozzle stand plate in place. Remove the
nozzle stand plate by pulling on the nozzle stand
until the plate releases from the cast-aluminum
blower casing.
Remove the two pump mounting screws that secure
the fuel pump in place. Turn the nozzle stand plate
over and remove the snap ring from the fuel pump
shaft, using snap ring pliers. Remove the nylon
drive gear and then the fuel pump.
Attach the new fuel pump to the nozzle stand plate
with the two pump mounting screws. Turn the nozzle stand plate over to install the nylon drive gear on
the fuel pump’s shaft and secure in place with the
snap ring. Dab the teeth of the nylon drive gear
with white lithium grease (Isoflex LDS-18 is recommended.)
NOTE: Do not adjust the fuel pressure regulator of the new
fuel pump, as it has been factory preset.
Inspect the nylon drive gear’s cavity inside the cast aluminum blower casting for fuel stains. If fuel stains are present,
a replacement of the bearings and/or the entire blower casing may be necessary. Leaking fuel could cause bearing
seizure, resulting in potential damage to the internal bore/
bearing of the blower casing.
7.
Fit the nozzle stand plate inside the cast-aluminum
blower casing and secure in place with the four nozzle stand plate screws. Install the grommets on the
fuel return and supply banjo pipes and secure the
pipes to the fuel pump with the new banjo bolts and
gasket rings.
NOTE: Failure to use the new gasket rings or the correct
order placement could result in a fuel leak.
8.
Reconnect the C-plug harness’ violet (+) and brown
(-) wires to the fuel solenoid’s (+) and (-) electrical
terminals.
9.
Insert both the ignition cables into the rubber grommet and slide into the appropriate notch on the
blower casing.
10. Reconnect the ignition cables to the ignition electrodes.
11. Reinstall the photo disc and secure it in place with
the retaining clip.
12. Reconnect the flame sensor’s green wire to the
green C-plug harness and the blue wire to the Cplug harness’ violet wire. Install rubber grommet
around the harness wires, and set into place.
NOTE: Check the ignition electrodes for proper adjustment
prior to reattaching the diesel burner.
13. Follow the directions for reattaching the diesel
burner in section 7 of this manual.
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SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Fuel Pump: (continued)
Figure 47
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SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Bearings:
5.
Remove the three hex head screws that secure the
motor and motor flange to the blower housing. Re
move the motor and flange assembly along with the
clutch halves. Disconnect the motor’s black (+) and
brown (-) wires from the C-plug harness’ wires.
6.
Remove the four blower housing screws that secure
the blower housing to the blower casing. Remove
the blower housing so that the combustion air
blower is exposed.
7.
Spin the combustion air blower by hand. Placing
one of the clutch halves to the end of the shaft, assists with the spinning of the bearings.
8.
If the combustion air blower rotates smoothly without any friction or noise, the bearings are in proper
working condition. If the combustion air blower
does not rotate smoothly and/or produces noise, the
bearings are worn and must be replaced.
The bearings support the combustion air blower’s
shaft and allows the blower to turn smoothly.
NOTE: In order to perform the following procedures it is
necessary to detach and reattach the diesel-burner
head. Be sure to review section 7 for detaching and
reattaching the diesel burner instructions
Bearing Test:
1.
2.
In order to perform the following procedure it is
necessary to detach and reattach the diesel-burner
head. Be sure to review the detaching and reattaching section for detaching and reattaching instructions.
Locate and disconnect the C-plug harness wires that
connect to the flame sensor and fuel solenoid. Also,
disconnect the ignition cables from the ignition
electrodes.
Replacement:
3.
Remove the four nozzle stand plate screws that secure the nozzle stand plate in place. Remove the
nozzle stand plate by pulling on the nozzle stand
until the plate releases from the cast-aluminum
blower casing.
1.
In order to perform the following procedure it is
necessary to detach and reattach the diesel-burner
head. Be sure to review the detaching and reattaching section for detaching and reattaching instructions.
4.
Remove the four ignition coil screws that secure the
ignition coil to the protection cap. Lift the ignition
coil and disconnect its black (+) and brown (-) wires
from the C-plug harness wires, prior to removing.
Remove the protection cap from the diesel-burner
so that the motor and clutch halves are exposed.
2.
Locate and disconnect the C-plug harness wires that
connect to the flame sensor and fuel solenoid. Also,
disconnect the ignition cables from the ignition
electrodes.
Figure 48
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SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
3.
Remove the four nozzle stand plate screws that secure the nozzle stand plate in place. Remove the
nozzle stand plate by pulling on the nozzle stand
until the plate releases from the cast-aluminum
blower casing.
NOTE: It is recommended to mark the internal components
of the diesel burner prior to disassembling of the burner.
Make a mark between the motor flange and the blower housing, and also between the blower housing and the blower
casing. If the burner is assembled improperly the protection
cap will not go on.
4.
5.
Remove the four ignition coil screws that secure the
ignition coil to the protection cap. Lift the ignition
coil and disconnect its black (+) and brown (-) wires
from the C-plug harness wires, prior to removing.
Remove the protection cap from the diesel-burner
so that the motor and clutch halves are exposed.
Remove the three hex head screws that secure the
motor and motor flange to the blower housing. Remove the motor and flange assembly along with the
clutch halves. Disconnect the motor’s black (+) and
brown (-) wires from the C-plug harness’ wires.
6.
Remove the four blower housing screws that secure
the blower housing to the blower casing. Remove
the blower housing so that the combustion air blower is exposed.
7.
Hold side-B of the blower casing and loosen the
retaining nut located in side-A of the blower casing.
Remove the retaining nut, steel drive gear and thick
flat washer from the combustion air blower’s shaft.
Lightly tap the threaded end of the shaft so that the
combustion air blower can be easily removed from
the blower casing.
NOTE: Be sure to inspect the blower casing’s bore/bearing
cavity for signs of damage due to potentially seized
bearings. If damage is present, the blower casing
must be replaced.
9.
Install a new snap ring into side-A of the blower
casing. Once the snap ring is in place, insert the
remaining contents of the new bearing kit into sideB of the blower casing, starting with the wave
washer. Secure the bearing kit assembly in place
with the remaining snap ring.
10. Inspect the combustion air blower for warping and/
or damage. If warping or damage is visible, the
combustion air blower must be replaced.
11. Reference Figure 49 for exact placement of the
three washers that slide over the threaded end of the
combustion air blower’s shaft prior to installation.
Failure to follow the correct order and direction of
the dished surfaces on the washers will result in a
restricted rotation of the combustion air blower.
12. Slide the combustion air blower’s shaft (with the
three washers) up through the bearing kit assembly
until the threaded portion appears on side-A of the
blower casing. Place the new thick flat washer and
steel drive gear on the threaded end of the combus
tion air blower’s shaft. Thread the new retaining
nut on the combustion air blower’s shaft until it is
finger tight (DO NOT TIGHTEN.)
Figure 49
NOTE: Be sure to observe the placement of the three washers of the bearing kit. To ensure proper tension, the
same order and direction of the dished surfaces of
the washers must be followed when reassembling.
8.
With a pair of snap-ring pliers, remove the snap
rings from both side-A and side-B of the blower
casing. Push all the contents of the bearing kit out
of the blower casing’s bore/bearing cavity. Discard
the retaining nut, steel drive gear, snap rings, bearings, spacer tube, and washers, as replacements are
provided in the new bearing kit.
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SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
12. Place a feeler gauge between the combustion air
blower and the flat surface of the blower casing.
Slowly tighten (or loosen) the retaining nut, holding
the combustion air blower, until a .003-.005 gap is
achieved. Remove feeler gauge.
13. Spin the combustion air blower to ensure a friction
free rotation.
NOTE: If the combustion air blower is rubbing, loosen the
retaining nut slightly and lightly tap on the combustion air blower’s shaft (opposite side) then readjust
the gap.
14. Reattach the blower housing to the blower casing
using the four blower housing screws. Reinstall the
clutch half on both the motor’s shaft and the combustion air blower’s shaft. Attach the motor and
flange assembly, with the recessed edge of the motor flange in-line with the wiring access slot of the
blower casing, to the blower housing with the three
hex head screws. Reconnect the black (+) and
brown (-) wires of the motor to the C-plug harness’
black (+) and brown (-) wires. Feed the C-plug
harness’ yellow and brown wires back through the
wiring access hole in the protection cap.
NOTE: Inspect the clutch halves’ for cracks and also ensure
that the flat portion in each shaft hole is free of
wear and tear. Too much play on the shaft produces a loud clacking noise. If any cracks or wear are
detected, the clutch half must be replaced.
15. Reinstall the protection cap. Reconnect the black
(+) and brown (-) wires of the ignition coil to the Cplug harness’ yellow (+) and brown (-) wires. Reinstall the ignition coil and secure to the protection
cap with the four ignition coil screws. Reconnect
the ignition cables to the ignition electrodes.
16. Fit the nozzle stand plate inside the cast aluminum
blower casing and secure in place with the four nozzle stand plate screws. Reattach the fuel supply and
return lines to the diesel-burner head.
17. Reconnect the blue (+) and brown (-) wires to the
fuel solenoid’s (+) and (-) electrical terminals. Also, reconnect the flame sensor’s green wire to the
green C-plug harness wire and the blue wire to the
C-plug harness’ violet wire.
18. Follow the instructions for reattaching the diesel
burner, in the detaching/reattaching section in this
manual.
Figure 50
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SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Ignition Coil:
The ignition coil produces a high voltage ignition
spark (approx. 8000 volts), which is released across
the metal tips of the ignition electrodes during the
initial diesel-burner start-up.
Use extreme care when testing the ignition coil, as a High
Voltage Shock may result.
NOTE: In order to perform the following procedures it is
necessary to detach and reattach the diesel-burner
head. Be sure to review the section for detaching
and reattaching the diesel burner..
Component Test:
1.
Remove the four ignition coil screws that secure the
ignition coil in place.
2.
Disconnect the ignition coil’s black (+) and brown
(-) wires from the C-plug harness’ yellow (+) and
brown (-) wires.
3.
Connect the ignition coil wires directly to a 12 volt
DC power supply (i.e. black (+) wire to (+) lead and
brown (-) wire to (-) lead).
4.
Turn the power supply ON and watch for a spark to
appear across the metal tips of the ignition electrodes. If a spark does not appear, the ignition coil
must be replaced.
NOTE: Some ignition coils are intermittent and will need
to be tested numerously
Before replacing the ignition coil:
1. Verify the ignition electrodes are not cracked or broken.
2. Verify that the ignition electrodes are adjusted properly.
3. Ensure the electrode boots are securely holding the
electrodes in place.
4. Ensure the electrode boots are not broken inside the ignition coil wires.
Figure 51
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SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Ignition Coil:
2.
NOTE: In order to perform the following procedures it is
necessary to detach and reattach the diesel-burner
head. Be sure to review the section for detaching
and reattaching the diesel burner..
Replacement Procedure:
1.
Disconnect the ignition cables from the ignition
electrodes. Remove the four ignition coil screws
that secure the ignition coil to the protection cap.
Lift the ignition coil and disconnect its wires from
the C-plug harness wires, prior to removing.
Connect the new ignition coil’s black (+) and brown
(-) wires to the C-plug harness’ yellow (+) and
brown (-) wires. Attach the ignition coil to the protection cap with the four ignition coil screws, then
reconnect the ignition cables to the ignition electrodes.
NOTE: If the new ignition coil does not function, check
wire connections and ensure they are properly connected.
3.
Follow the instructions for reattaching the diesel
burner and test for proper operation.
Figure 52
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SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Diesel-Burner Controller:
The diesel-burner controller operates all the components of the diesel-burner head and safely shuts the
heater OFF in the event of an overheat, flameout,
and low voltage condition. It also receives dieselburner operation status signals from the flame sensor, VDC control thermostat, and VDC high-limit
thermostat.
Component Test:
VDC/VAC Control Thermostat Circuit Test:
Locate the diesel-burner controller’s B-plug and Cplug. Insert the probes of a DC voltmeter into the C
-1 (+) and B-2 (-) locations and turn the diesel
switch ON. If a voltage reading does not register on
the voltmeter, the diesel-burner controller must be
replaced. If voltage is present, proceed to the next
circuit test.
VDC High-Limit Thermostat Circuit Test:
The following conditions must exist prior to performing the diesel-burner controller circuit tests on
the following page. If one of the conditions below
does not exist, please contact our technical support
department at 1-800-685-4298 for additional assistance.
Condition #1
A battery voltage level between 11.5 to 14.0 volts
DC must be present at the diesel-burner controller
during all testing. It may be necessary to perform a
voltage check to ensure that this condition exists.
To perform the voltage check, locate the dieselburner controller’s B-plug, and insert the probes of
a DC voltmeter into the B-4 (+) and B-2 (-) locations.
Condition #2
A voltage level of between 11.5 to 14.0 volts must
be present at the diesel ON/OFF switch circuit of
the diesel-burner controller during all testing. It
may be necessary to perform a voltage check to
ensure that this condition exists. To perform the
voltage check, locate the diesel-burner controller’s
B-plug, and insert the probes of a DC voltmeter into
the B-1 (+) and B-2 (-) locations. Turn the diesel
switch ON and observe the voltage level.
Ground Circuit Test:
Locate the diesel-burner controller’s B-plug and Cplug. Insert the probes of a DC voltmeter into the B
-4 (+) and C-5 (-) locations and turn the diesel
switch ON. If a voltage reading does not register on
the voltmeter, the diesel-burner controller must be
replaced. If voltage is present, proceed to the next
circuit test.
Locate the diesel-burner controller’s B-plug and Cplug. Insert the probes of a DC voltmeter into the C
-4 (+) and B-2 (-) locations and turn the diesel
switch ON. If a voltage reading does not register on
the voltmeter, the diesel-burner controller must be
replaced. If voltage is present, proceed to the next
circuit test.
Motor Circuit Test:
Locate the diesel-burner controller’s B-plug and Cplug. Use a jumper wire to make a connection from
the C-1 location to the C-7 location. Turn the diesel
switch ON and insert the probes of a DC voltmeter
into the C-2 (+) and C-5 (-) locations. If no voltage
reading registers on the voltmeter, the diesel-burner
controller must be replaced. If voltage is present,
proceed to the next circuit test.
Be sure to remove the jumper wire that was used to make the
connection from the C-1 location to the C-7 location. A failure to do so will result in an overheating condition during
normal operation.
Ignition Coil Circuit Test:
Turn the diesel switch OFF and locate the dieselburner controller’s C-plug. Also, locate the VDC
high-limit thermostat and disconnect it’s 2-way
male plug from the (white plastic) 6-way female
connector. Insert the probes of a DC voltmeter into
the C-8 (+) and C-5 (-) locations and turn the diesel
switch ON. If a voltage reading does not register on
the voltmeter 18-25 seconds after the initial start-up
the diesel-burner controller must be replaced.
NOTE: Be sure to reconnect the VDC high-limit thermostat’s wires to the thermostat. The diesel-burner
will not ignite during normal operation if the VDC
high-limit thermostat is left disconnected.
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SECTION 8: DIESEL-BURNER COMPONENTS/TROUBLE SHOOTING
Be sure to remove the jumper wire that was used to make the
connection from the C-1 location to the C-7 location. Failure
to do so will result in an overheating condition during normal
operation.
Replacement Procedure:
1. Remove both the B-plug and the C-plug from the
diesel-burner controller. Gently pry away each side
of the diesel-burner controller bracket from the diesel-burner controller’s locking posts with a flat-head
screw driver. Once the locking posts have been
released, pull on the diesel-burner controller to remove it from the diesel-burner head.
2. Slide the new diesel-burner controller into the diesel
-burner controller bracket. Push down on the diesel
-burner controller until the locking posts snap into
the bracket slots.
3. Reconnect the B-plug and the C-plug.
NOTE: Be sure to install the diesel-burner controller with
it’s C-plug and B-plug ports facing downward.
Failure to do so, will result in moisture collecting in
the ports and potential damage to the diesel-burner
controller’s internal circuitry.
Figure 53a
Figure 53b
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SECTION 9: GENERAL TROUBLESHOOTING
IF THE AQUA-HOT
IS
BLACK SMOKING:
1. Things to check before opening up heater
1. Low Voltage - Fire up generator/plug coach into shore power
2. Damaged or Restricted exhaust pipe - Inspect exhaust pipe for damage
2. Access cover must be removed to check the following:
1.
2.
3.
4.
Air Intake Closed off - on the bottom of the burner is the air adjustment, set at the half way point.
Broken Protection Cap - Check cap for cracks or missing pieces.
Worn OUT Grommets – run hands over grommets, on top and bottom, and feel for excessive air
Burner not seated properly or Loose - run hands along the seal of the burner, and check for excessive air
5. Air Intake Sleeve collapsed
3. Diesel Burner must be removed to check the following:
1.
2.
3.
4.
Photo Disc Bent or Tight – The photo disc must be loose, so it will seal on the combustion chamber properly
Combustion Chamber Warped/Melted – Inspect for signs of warping/melted aluminum.
Bad Nozzle - If nozzle is spraying poorly, it must be replaced
Fuel Pressure not at 145 PSI – Check fuel pressure with fuel pressure gauge
4. Diesel Burner must be torn down to check the following:
1. Slow Motor (Less Than 4500rpms at 12v) -
a slow motor acts the same as low voltage. Check motor rpm
with an rpm tester, under full load.
2. Bearings are worn out - Bearings should spin freely, and sound smooth.
If they are starting to seize up, they will
slow the motor down.
3. Impeller Fan Not Gapped Properly – The impeller needs to be gapped at 3-5 thousands or tighten fan down
until it rubs, back it off ¼ turn.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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SECTION 9: GENERAL TROUBLESHOOTING
IF THE AQUA-HOT
IS
BLUE/WHITE SMOKING:
1. If The Heater Smokes on Start up/Shut down.
a. Fuel solenoid
- plunger worn out
- plastic/metal in the way of plunger
- fuel solenoid intermittent.
b. Nozzle Tower
- cracked
- poorly machined
c. Short cycling
- control t-stat bad
- someone turned heater off/on repeatedly
d. Return Fuel Check Valve
- heaters manufactured before 2001
NOTE: It is normal for the heater to blue/white
smoke for 3-5 seconds on start up and shut down.
2. If The Heater Smokes During The Burn Cycle.
a. Electrodes out of adjustment
b. Air in the fuel system
c. Bad nozzle
d. Fuel pressure
e. Fuel Pump
f.
Intermittent Ignition Coil
- If the coil doesn’t turn on, the fuel sprays for 20 seconds, before the photo eye
shuts the fuel off.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 71 —
SECTION 9: GENERAL TROUBLESHOOTING
IF ONE
OF
THE AQUA-HOT HEATING ZONES
WILL NOT GET HOT:
1. General Problems
A. Diesel/Electric not operating (antifreeze cold)
B. Heater is Not up to operating Temperature
(antifreeze is cold)
C. Interior Zone Thermostat Not calling for heat
D. Zone Circulation Pump Not Operating
E. Heat Exchanger Fans Not Operating
2. If Fans and Pumps are Running
A. Stuck Check Valve
B. Kinked Line
C. No Antifreeze in system
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 72 —
SECTION 9: GENERAL TROUBLESHOOTING
IF THERE IS A LACK
OF
DOMESTIC HOT WATER:
1: General information
1. The heater is only rated for water flow of 1.5 GPM
2. The heater is only rated for a 55*F temperature Rise on the cold water coming into
the unit
3. The diesel burner must be on for continuous hot water, the electric element is for limited use only.
2: Things to test for a lack of hot water problem.
1. Aqua-Hot Heater Bypassed
2. Outside Water Faucet is left on.
3. Washing Machine Valve has gone bad
4. Antifreeze Concentration is incorrect.
a. 30%-50% antifreeze concentration
5. Operating Range of the heater (I.E. Control Thermostat) is incorrect
a. 175° F - 210° F
6. Water Flow is too fast
a. Must be 1.5 GPM or Less.
7. Mixer Valve is stuck (knob does not turn freely)
8. Copper Coil is not bonded properly to the outside of the boiler tank.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 73 —
SECTION 9: GENERAL TROUBLESHOOTING
IF THERE IS ANTIFREEZE LEAKING:
NOTE: To find an antifreeze leak, the system must be Hot (up to operating temperature)
Or pressurized to 17 PSI.
Inspect the following components on the Aqua-Hot Heating System for Leaks:
1. On the Front-Side of Aqua-Hot 1. Electric element
2. Circulation/Stir pump
c. Copper plumbing
d. Tank ports
- It might be necessary to cut away some of the insulation around the tank
ports to locate the leak.
e. Pump
6. Burn Chamber Leak
a. If Antifreeze is running out of the tip of the exhaust pipe remove the burner, and
combustion chamber and inspect inside the burn chamber for leaks.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 74 —
SECTION 9: GENERAL TROUBLESHOOTING
IF THERE IS ANTIFREEZE LEAKING: (CONTINUED)
2. On the Top-Side of Aqua-Hot 1. Expansion Tank Connection
a. Cracked expansion tank tubing
b. Radiator Cap
c. Filler neck/Filler neck solder joing
2. Supply/Return Ports
A. Defective fitting
B. Leaking fitting
Note: If no leaks are found on the Aqua-Hot, it is possible
that there is a leak within the motor home. Check all Heat
exchangers, connections, and tubing for leaks.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 75 —
APPENDIX A: WIRING DIAGRAM
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 76 —
APPENDIX A: WIRING DIAGRAM
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 77 —
APPENDIX B: BLEEDING
THE INTERIOR
A. Place a bucket underneath the coach, where the
Aqua-Hot’s Drain Valve is located.
NOTE: Be sure to check that the drain valve is completely closed.
HEATING ZONE CIRCULATION PUMP
I.
Close the Drain Valve.
J.
Close the pump manifold valve.
K. Repeat steps B-J for all three zone pumps (i.e. Bedroom,
Bathroom, and Living Room).
B. Remove the Aqua-Hot’s Radiator Cap and pour 15
gallons of a 50/50 solution of water and antifreeze,
reference figure B1.
C. Place the radiator cap back onto the Aqua-Hot and tighten.
D. Close both pump and return manifold valves, reference
Figure B2
E. Activate the Bedroom Zone Pump.
F.
Pressurize the system by applying air pressure to the
filler neck overflow tube, reference figure B3. Pressurize until the pressure release tab releases (blows out the
excess air pressure).
NOTE: The system may also be pressurized using a
Cooling System Tester. Reference Figure B4
G. Open the pump manifold valve (upper valve). Reference Figure B2. This will allow the solution to enter
into the heating system (i.e. zone pumps, heat exchangers and plumbing lines).
NOTE:
1. Depending on the plumbing lines diameter and total
length it may be necessary to repeat B-J several times
before any of the solution appears.
2. Be sure to close both the drain valve and the pump
manifold valve each time that the boiler tank is refilled
and pressurized.
3. Make sure that the Aqua-Hot’s boiler tank has a minimum of 11 gallons of solution in it at all times while
bleeding the heating system. If the capacity should
drop below the 11 gallon minimum, air will enter back
into the heating system and the bleeding process will
need to be repeated.
L. Once all air had been bled from the system, be sure that
both the return manifold valve (lower), located on the
left side of the diesel burner and the pump manifold
valve (upper) are completely opened. Reference
Figure B2.
M. Once all air has been bled from the system, be sure to
connect and clamp the overflow tubing to the AquaHot’s Expansion tank.
H. Slowly open the drain valve to allow the air to escape.
Reference Figure B2.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 78 —
APPENDIX B: BLEEDING
THE INTERIOR
HEATING ZONE CIRCULATION PUMP
Living room Supply
Living room Return
13 lb Radiator
Cap
Bathroom Supply
Bathroom Return
Bedroom Supply
Bedroom Return
Figure B1
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 79 —
APPENDIX B: BLEEDING
Figure B2
THE INTERIOR
HEATING ZONE CIRCULATION PUMP
Return Ball
Valve
Supply Ball
Valve
Drain Valve
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 80 —
APPENDIX B: BLEEDING
THE INTERIOR
HEATING ZONE CIRCULATION PUMP
Using an Air Blower to pressurize the Boiler Tank
Expansion
Tank Tubing
13 lb
Radiator Cap
Air
Blower
Figure B3
NOTE: If too much air pressure is applied to the boiler tank, it will leak out
around the radiator cap’s rubber seal.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 81 —
APPENDIX B: BLEEDING
THE INTERIOR
HEATING ZONE CIRCULATION PUMP
Using a Coolant System Tester to pressurize the Boiler Tank
Coolant System Tester
Pressurize System
up to 15 psi
Figure B4
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 82 —
APPENDIX C: FUEL PRESSURE CHECK
AND
ADJUSTMENT
Instructions for Checking Fuel Pressure
NOTE:
A fuel pressure gauge is used to properly check the fuel pump’s pressure setting. The fuel pump is preset to 145 PSI. Perform the
following procedures to check for a proper fuel pressure setting.
NOTE: In order to perform the following procedure it is necessary to detach and
reattach the diesel-burner head. Be sure to review the detaching/attaching instructions.
Step 1: Remove the diesel-burner
Figure C1
1. Refer to the section on detaching/reattaching the diesel burner, to detach the diesel burner.
Step 2: Installing the fuel pressure gauge
Figure C2
1. Using a 5/8” and a 3/4” wrench remove the fuel nozzle.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 83 —
APPENDIX C: FUEL PRESSURE CHECK
AND
ADJUSTMENT
Instructions for Checking Fuel Pressure
Figure C3
2. Using a 5/8” and a 3/4” wrench install the fuel pressure gauge.
WARNING!
A spark will appear across the ignition electrodes for a brief moment after the diesel burner has been activated.
DO NOT attempt to make any fuel pressure adjustments until the spark has disappeared. Failure to do so may
result in serious bodily injury. In some installations it may be necessary to shine a light on the flame sensor to
simulate a flame condition to shot of the ignition coil.
Figure C4
2. Turn the diesel burner switch to the on position. A pressure will register on the fuel pressure gauge
once the fuel solenoid opens (after approx. 10-20 seconds.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 84 —
APPENDIX C: FUEL PRESSURE CHECK
AND
ADJUSTMENT
Instructions for Adjusting Fuel Pressure
Step 1: Follow the directions for Checking the Fuel Pressure in this section.
Figure C5
1. Remove the Diesel Burner and install the Fuel Pressure Gauge .
WARNING!
A spark will appear across the ignition electrodes for a brief moment after the diesel burner has been activated.
DO NOT attempt to make any fuel pressure adjustments until the spark has disappeared. Failure to do so may
result in serious bodily injury. In some installations it may be necessary to shine a light on the flame sensor to
simulate a flame condition to shot of the ignition coil.
Figure C6
2. Turn the diesel burner switch to the on position. A pressure will register on the fuel pressure gauge
once the fuel solenoid opens (after approx. 10-20 seconds.)
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 85 —
APPENDIX C: FUEL PRESSURE CHECK
AND
ADJUSTMENT
Instructions for Adjusting Fuel Pressure
Step 2: Adjust the Fuel pressure to 145 PSI.
Figure C7
1. Once the fuel solenoid has been activated, and the fuel pressure gauge is registering a pressure, the
fuel pressure can be adjusted. To increase the fuel pressure turn the pressure adjustment screw clockwise, and to reduce the fuel pressure, turn the pressure adjustment screw counter clockwise.
NOTE: If the fuel pressure cannot be adjusted refer to the fuel pump section in section 8 Of this manual for troubleshooting tips.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 86 —
APPENDIX D: EXTREME COLD WEATHER OPERATION
Diesel-Burner
When storing the Motorhome: Not winterizing the AquaHot when freezing temperatures are present will result in
serious damage to the Aqua-Hot’s Domestic Water Heating
System. Also, be sure to use an FDA approved, “GRAS”
rated antifreeze for winterization.
1. If the Diesel burner Fails to operate:
NOTE: The Aqua-Hot can continue to be used for interior
zone heating once the domestic water heating system
has been drained and winterized.
A. Is the Diesel Fuel in the motor home winter
fuel or summer fuel?
B. Is the Diesel Fuel liquid or Jelled?
C. Are the electrodes properly adjusted?
D. When was the last time an Annual Service
was performed?
120 Volt-A.C. Electric Heating Element
Please note that the 120 Volt-AC Electric Heating Element is
the Aqua-Hot’s secondary heat source for heating both the
interior and/or the domestic hot water during low heating demand situations (such as when moderate ambient temperatures
exist and/or when there is a low demand for domestic hot water).
If the 120 Volt-AC Electric Heating Element is not providing
enough heat, turn the Diesel-Burner on, in conjunction with the
120 Volt-AC Electric Heating Element.
Figure D1
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 87 —
APPENDIX D: EXTREME COLD WEATHER OPERATION
If there is a lack of interior Heat:
Note:
The 120 Volt-AC Electric Heating Element is
the Aqua-Hot’s secondary heat source for heating both
the interior and/or the domestic hot water during low heating demand situations (such as when moderate ambient
temperatures exist and/or when there is a low demand for
domestic hot water). If the ambient temperature is ex-
1. Is the Diesel Burner activated?
2. Is the Diesel Burner operating Properly?
3. What is the antifreeze concentration, inside of the
Aqua-Hot Boiler Tank?
4. Was the heating system properly installed, following the
Aqua Hot installation manual?
Figure D2
A. Are there at least 5 heat exchangers installed in the
Interior of the motor home?
B. Are there cold air returns installed for every heat
exchanger? Reference Figure D2
C. Are the heat exchangers mounted as close to the
hot air outlet grill as possible? Reference
Figure D2.
Figure D3
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 88 —
APPENDIX E: AQUA-HOT MAINTENANCE
Monthly Maintenance:
Annual Maintenance:
Check the antifreeze and water heating solution to ensure
that it is at the proper level by visually checking the solution
level in the expansion tank. The level of the antifreeze and
water heating solution within the expansion tank should only
be checked when the Aqua-Hot is at maximum operating
temperature.
If additional antifreeze and water heating solution is required, fill the expansion tank to the “HOT” level mark.
Additionally, it is recommended that the diesel-burner be
fired and allowed to run monthly to keep it in good working
order.
FAILURE TO DISCONNECT ALL POWER SUPPLIES AND/OR
TO ALLOW THE HEATER TO COOL BEFORE SERVICING
COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY.
To keep the Aqua-Hot running smoothly, it is recommended
to have the diesel-burner tuned up annually. A tune-up
should consist of a new fuel nozzle and fuel filter, along with
a thorough cleaning of the combustion chamber. To ensure
maximum diesel-burner performance, always use the recommended fuel nozzle and fuel filter when replacing these
parts.
NOTE: Be sure to use care when handling the fuel nozzle.
Oils and/or small dust or dirt particles from the
hands may plug the nozzle’s small orifice. A partially plugged orifice will restrict fuel flow, which
will affect the combustion process of the dieselburner.
Figure E1
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 89 —
APPENDIX E: AQUA-HOT MAINTENANCE
Aqua-Hot Maintenance Procedure:
Note: Before performing an annual
maintenance, it is recommended to test run
the Diesel-Burner. While testing inspect
exhaust for smoke.
Step 1: Test Run the Diesel Burner
1. Turn the Diesel-Burner Switch to the on position.
2. After the Diesel-Burner has ignited, inspect
the exhaust for smoke.
3. Shut the Diesel-Burner off, and wait for unit
to completely shut off.
NOTE: The diesel-burner can either be shut off by:
1. Turning the Diesel Burner switch to the off position.
2. Disconnecting the control thermostat wires
3. Unplugging the diesel burner controller.
Reference Figure ??
Step 2: Replace the Fuel Filter
1. Locate Fuel Filter.
2. Using hose pinch off pliers, clamp off both
fuel lines going to the fuel filter. Reference
figure ??.
3. Replace fuel filter, with proper replacement
canister.
NOTE: It is recommended that the replacement fuel filter
be filled with clean diesel fuel, prior to installation
4. Remove hose pinch off pliers.
Step 3: Run the Diesel Burner
1. Turn the Diesel-Burner Switch to the on position.
2. After the Diesel-Burner has ignited, let it
burn for 1 - 2 minutes to purge the old fuel
out of the nozzle holder, to prevent contamination of the replacement nozzle.
3. Shut the Diesel-Burner off, and wait for unit
to completely shut off.
NOTE: The diesel-burner can either be shut off by:
1. Turning the Diesel Burner switch to the off position.
2. Disconnecting the control thermostat wires
3. Unplugging the diesel burner controller.
Reference Figure ??
Thermostat
Connector
Figure E3
Figure E2
Diesel Burner
Controller Plugs
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 90 —
APPENDIX E: AQUA-HOT MAINTENANCE
Aqua-Hot Maintenance Procedure:
Step 4: Remove The Diesel Burner
Figure E4a
1. Locate the Diesel-Burner’s Controller and disconnect both plugs.
Figure E4b
Figure E4c
3. The Diesel-Burner is secured to the Aqua-Hot with two nuts that can be loosened, and swung out of
the way by using a 10mm socket wrench with a 10 inch long extension.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 91 —
APPENDIX E: AQUA-HOT MAINTENANCE
Aqua-Hot Maintenance Procedure:
Step 5: Remove The Diesel Burner (continued)
Figure E5
Thermostats
Diode Wire
4. Carefully pull the Diesel-Burner away from the Aqua-Hot 4 to 5 inches before
rotating the burner, and then remove.
NOTE: To remove the diesel burner, it may be necessary to disconnect the wires from the control and hi
limit thermostats It may also be necessary to disconnect the Diode Wire.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 92 —
APPENDIX E: AQUA-HOT MAINTENANCE
Step 6: Clean and Inspect the Combustion Chamber and Heat Transfer Tabs.
Use caution when handling the combustion chamber, it may be extremely
hot, and serious burns could result from touching a hot combustion chamber.
Heat Transfer
Tabs
Figure E6a
Figure E6b
1. Remove the combustion chamber by pulling it
straight out, approximately 16 inches.
2. Once the combustion chamber has been removed.
Use a long handled wire brush, and brush the heat transfer tabs, to loosen soot deposits. Failure to do so will
reduce the Aqua-Hot’s heat transfer capabilities.
NOTE: If the heat transfer tabs are excessively sooty, it may be necessary to vacuum the soot out of the heat transfer
tabs. If there is a minimal amount of soot, it may be left in the heat transfer tabs, and will be evacuated out the exhaust
pipe, upon start up of diesel burner.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 93 —
APPENDIX E: AQUA-HOT MAINTENANCE
Step 6: Clean and Inspect the Combustion Chamber and Heat Transfer Tabs.
Figure E6c
Seam on stainless steel tube
Back side of air
swirler
Outer ring that the photo
disc seats against
3. Inspect the combustion chamber for damage or signs of warping.
1. Inspect the combustion chamber for cracks appearing along the seam of the stainless steel tube.
A. If the crack is over 1” in length, the combustion chamber must be replaced.
2. Inspect the aluminum Air Swirler for signs of warping. If any part of the air swirler is warped the
combustion chamber must be replace.
A. Inspect the outer ring that the photo disc seats against for signs of warping.
B. Inspect the back side of the Air Swirler for signs of warping between screws.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 94 —
APPENDIX E: AQUA-HOT MAINTENANCE
Step 7: Reinstall the Combustion Chamber
CAUTION!
Failure to reinstall the combustion chamber will result in serious damage to the diesel burner.
Figure E7
Seam on stainless
steel tube
1. Reinstall the combustion chamber into the Aqua-Hot. Please note: the seam on the stainless steel tube must
be in the “up” position. Failure to do so could result in premature failure of the combustion chamber.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 95 —
APPENDIX E: AQUA-HOT MAINTENANCE
Step 8: Inspect Diesel-Burner
Figure E8
Electrode
Fuel Nozzle
Fuel Pump
Grommet
Photo Disc
Ear
Flame Sensor
Inspect the following:
1.
Electrodes
- damaged
- improperly adjusted
2.
Fuel Pump
- leaks
3.
Photo disc
- warped
- bent
4.
Harness & Ignition Coil Wires
- crack or bare wires
- Hard or brittle wires
5.
Flame Sensor
- cracked
- overheated (purple color)
- melted wires
- dirty
6.
Rubber Grommets
- hard/brittle
- rubber has been cut out
- right/left
7.
Broken or cracked “Ears”
- due to over tightening of eyebolts.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 96 —
APPENDIX E: AQUA-HOT MAINTENANCE
Step 9: Clean Ignition Electrodes and Flame Sensor
Metal Tips
Figure E9
Flame Sensor
1.
Ignition electrodes A. Polish away any carbon deposits that may have baked onto the metal tips of the ignition
electrodes with a course sponge.
2.
Flame Sensor A. For light dirt, dust, and/or carbon deposits, simply wipe off the flame sensor with a soft
cloth.
B. Should heavy carbon deposits be present, completely remove the flame sensor from the
photo disc and clean with brake cleaner.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 97 —
APPENDIX E: AQUA-HOT MAINTENANCE
Step 10: Replace The Fuel Nozzle
Figure E10
1. Use a 3/4 in. wrench to hold the fuel nozzle manifold hex, while loosening the fuel nozzle with a 5/8 in. wrench and remove.
NOTE: Be sure to use care when handling the new fuel nozzle. Oils and/or small dust or dirt particles from your hands may plug
the nozzle’s small orifice. A partially plugged orifice will restrict fuel flow, which will affect the combustion process of
the diesel-burner.
2.
When replacing the fuel nozzle, be sure to tighten the nozzle, loosen it a 1/4 turn, and then firmly retighten. This will establish a seated fit and avoid any leaks.
Be sure to reattach the diesel-burner head prior to switching
the heater ON. Failure to do so may result in ignition of the
diesel-burner and serious bodily injury.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 98 —
APPENDIX E: AQUA-HOT MAINTENANCE
Step 11: Adjust Ignition Electrodes
Figure E11
1.
Using a 10mm socket, slightly loosen the retaining clamp bolt.
2. Place the electrode adjustment gauge on the nozzle manifold hex and insert the metal tips of the ignition electrodes into the
appropriate notches of the electrode adjustment gauge.
3.
Using a 10 mm socket, tighten the retaining clamp bolt.
NOTE: Be sure not to over-tighten the retaining clamp bolt when readjusting the ignition electrodes. Over-tightening the retaining
clamp bolt will bend the retaining clamp and prevent the photo disc from floating freely. Not allowing the photo disc to
float freely will cause poor combustion and result in a smoky exhaust. A bent retaining clamp can be re-straightened with a
punch and hammer. Lay the clamp’s beveled side down on a solid flat surface and align the thick end of the punch at dead
center. Tap the punch lightly until the retaining clamp returns to proper form.
4. Remove the electrode adjustment gauge.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 99 —
APPENDIX E: AQUA-HOT MAINTENANCE
Step 12: Inspect Photo Disc
Figure E12
Photo Disc
1.
If the photo disc is not free floating, the electrode clamp bolt has been over-tightened, and has bent the electrode clamp. Using a
10mm socket remove the electrode clamp, and re-straighten.
-Lay the clamp’s beveled side down on a solid flat surface and align the thick end of the punch at dead center. Tap the
punch lightly until the retaining clamp returns to proper form.
Step 13: Re-Install Diesel Burner
Figure E13a
Figure E13b
NOTE: When reinstalling the diesel burner be careful not to damage the photo disc or bend the electrodes.
Also, be careful to not pinch any wires between the burner and the Aqua-Hot Tank.
1. Align the Diesel-Burner with the Aqua-Hot, using the alignment tabs welded on the Aqua-Hot.
2. Swing the Eye Bolts around the “Ears” on the diesel burner and securely tighten, using a 10mm socket with a 10
inch long extension.
Use extreme caution when tightening down the eye-bolt nuts, over tightening of the eye-bolt nuts can
cause the aluminum blower casing to crack. (Torque Specifications = Approximately 20-40 in. lbs.)
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 100 —
APPENDIX E: AQUA-HOT MAINTENANCE
Step 14: Plug in the diesel-burner’s controller and mount
Figure E14a
1. Locate the Diesel-Burner’s Controller and connect both plugs.
NOTE: The Diesel Burner’s Controller might have to be mounted onto the side of the diesel burner, before the
plugs are inserted into the control unit, otherwise it might not be possible to mount the control unit.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 101 —
APPENDIX E: AQUA-HOT MAINTENANCE
Step 15: Re-Install the Aqua-Hot Access Cover
1. Reinstall the Aqua-Hot’s access cover .
2. Securely tighten the screws securing the access
cover in place.
Step 16: Test for Normal Operation
A. Turn the Diesel-Burner switch on, and let the diesel burner run for a complete cycle, until it shuts
off on it’s own..
B. After the Diesel-Burner has shut off, turn on the interior heat/run hot water, until the Diesel
Burner cycles back on. When the diesel burner cycles back on, check the exhaust for signs of
smoke.
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 102 —
APPENDIX F: WINTERIZATION PROCCESS
Not winterizing the Aqua-Hot when freezing temperatures
are present will result in serious damage to the Aqua-Hot’s
Domestic Water Heating System. Also, be sure to use an
FDA approved, “GRAS” rated antifreeze for winterization.
NOTE: The Aqua-Hot can continue to be used for interior
zone heating once the domestic water heating system
has been drained and winterized.
5.
Open and close all interior and exterior water faucets, one at
a time, until only pure RV Antifreeze is present. Perform
this procedure for both the hot and cold faucets.
6.
Turn off Demand Water pump and remove the hose and reconnect the domestic water demand pump’s suction line to
the fresh water storage tank.
An FDA approved “GRAS” rated winterization antifreeze
must be used. YOU CANNOT BLOW DOMESTIC WATER
COIL OUT WITH AIR TO WINTERIZE AQUA-HOT.
The Aqua-Hot’s Domestic Water Heating System must be
completely drained of domestic water any time the heater is
stored where freezing temperatures may be experienced.
De-Winterizing the Domestic Water Heating System:
Winterizing the Domestic Water Heating System:
For de-winterization, completely fill the fresh water storage tank.
Turn on demand water pump and open and close all interior and
exterior water faucets, one at a time, until only clear water is
present/visible. Reference Figure F1.
Please follow these instructions when winterizing the AquaHot’s Domestic Water Heating System; reference Figure F1:
Completely drain the fresh water storage tank.
2.
Disconnect the domestic water demand pump’s suction
line from the fresh water storage tank.
3.
Attach an adequate piece of hose onto the suction side of
the domestic water demand pump.
4.
Place the opposite end of the hose into an adequate supply
of FDA-approved “GRAS” RV Antifreeze, and turn on the
demand water pump.
Recreation Vehicle Industry Association
1896 Preston White Drive
P.O. Box 2999
Reston, VA 20195-0999
Figure F1
1.
If disinfecting the potable water system after de-winterizing, be
sure to follow RVIA’s “Instructions for Disinfection of Potable
Water Systems on Recreation Vehicles.” These instructions
can be obtained by contacting the Recreational Vehicle Industry
Association at (703) 620-6003, visiting them online at
www.rvia.com, or writing to them at the following address:
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
— Page 104 —
© 2011 Aqua-Hot® AHE-100-02S Hydronic Heating System Service Manual—Rev. B
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AHE-100-02S
SERVICE MANUAL
15549 East Highway 52 | Fort Lupton, CO 80621
Toll free: 800.685.4298 | phone: 303.659.8221 | fax:303.857.7881
www.aquahot.com
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