SERVICE MANUAL
VSX BOILER BASE SERIES
CONVECTION STEAMERS
(GAS, ELECTRIC, DIRECT AND REGENERATED)
VSX24G
ML-52163
VSX24D
ML-52827
VSX36G
ML-52360
VSX36D
ML-52830
VSX42GT
ML-52376
VSX42DT
ML-52834
VSX24E
ML-52164
VSX36R
ML-52831
VSX36E
ML-52829
VSX42RT
ML-52835
VSX42ET
ML-52833
VSX24G SHOWN
- NOTICE This Manual is prepared for the use of trained Vulcan Service
Technicians and should not be used by those not properly
qualified. If you have attended a Vulcan Service School for this
product, you may be qualified to perform all the procedures
described in this manual.
This manual is not intended to be all encompassing. If you have
not attended a Vulcan Service School for this product, you should
read, in its entirety, the repair procedure you wish to perform to
determine if you have the necessary tools, instruments and skills
required to perform the procedure. Procedures for which you do
not have the necessary tools, instruments and skills should be
performed by a trained Vulcan Service Technician.
Reproduction or other use of this Manual, without the express
written consent of Vulcan, is prohibited.
A product of VULCAN-HART
Form 24627 (12/98)
LOUISVILLE, KY 40201-0696
VSX SERIES STEAMERS
TABLE OF CONTENTS
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compartment Pan Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Model Designations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Steamers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electric Steamers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steam Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Conditioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
4
4
4
5
5
5
5
6
6
6
STEAMER OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cabinet Base Boilers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Powered Steam Boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrically Powered Steam Boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Direct Steam Powered Cooker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Regenerated Steam Powered Boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Boiler Blowdown and Steamer Shut off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooking Compartment Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
7
7
8
8
8
8
9
COMPONENT FUNCTION AND LOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Cabinet Base Boiler Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Cooking Compartment Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
SERVICE PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cabinet Bases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Descaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Level Controls
(Low Level Cut-Off and Differential) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Level Gauge Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Switches (Gas and Electric Models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High Limit Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing The Boiler Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fill and Cold Water Solenoid Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Not Being Supplied to Boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Blowdown Solenoid Valve Does Not Drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steamer Achieves Pressure Slower Than Normal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inlet Water Strainer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pilot, Thermocouple or Main Burners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic Ignition Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Combination Control Valve Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manifold Pressure Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electric Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Magnetic Contactor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heating Element . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Direct Steam Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Regenerated Steam Models (Steam Coil) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COOKING COMPARTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steam Supply Solenoid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Accumulating in Compartment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooking Cycle Cannot Be Activated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Intake Shut-Off Valve Adjustment (Steam Flow) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 2 of 80
15
15
15
16
16
17
17
18
18
18
19
19
20
21
21
21
22
23
23
24
24
24
26
26
26
26
26
27
27
27
27
VSX SERIES STEAMERS
ELECTRICAL OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Level Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Solid State Low level Cut-Off & Differential Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electro Mechanical - Low level Cut-Off & Differential Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electric Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematics, Gas Steamers, Boiler Controls
VSX24G, 36G and 42GT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual Ignition, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electronic Ignition, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual Ignition, CSD-1 Code Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electronic Ignition, CSD-1 Code Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring Diagrams, Gas Steamers, Boiler Controls
VSX24G, 36G AND 42GT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual Ignition, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electronic Ignition, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual Ignition, CSD-1 Code Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electronic Ignition, CSD-1 Code Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematics, Electric Steamers, Boiler Controls
VSX24E, 36E AND 42ET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto Blowdown, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto Blowdown, Cal-Code Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto Blowdown, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto Blowdown, Cal-Code Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring Diagrams, Electric Steamers, Boiler Controls
VSX24E, 36E AND 42ET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto Blowdown, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto Blowdown, Cal-Code Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto Blowdown, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto Blowdown, Step Down Transformer, Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto Blowdown, Step Down Transformer, Cal-Code Controls (2 contactors) . . . . . . . . . . . . . . .
Auto Blowdown, Step Down Transformer, Cal-Code Controls (4 contactors) . . . . . . . . . . . . . . .
Wiring Diagrams, Electric Heater Circuits
VSX24E, 36E AND 42ET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic, Direct Steamers, Cabinet Base
VSX24D, 36D and 42DT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring Diagram, Direct Steamers, Cabinet Base
VSX24D, 36D and 42DT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring Diagrams, Regenerated Steamers, Boiler Controls
VSX36R and 42RT (Older Models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic All Models - Compartment Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring Diagram, All Models - Compartment Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
30
30
32
34
34
37
41
41
42
43
44
46
46
48
50
52
54
54
55
56
57
58
58
60
62
64
66
68
70
73
73
74
76
77
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
© VULCAN 1998
Page 3 of 80
VSX SERIES STEAMERS - GENERAL
GENERAL
Boiler Code Descriptions
INTRODUCTION
General
This manual is applicable for all models listed on the
cover page. A convection steamer on a 42 inch
base with a tilting kettle is pictured below for
reference.
Vulcan-Hart incorporates redundant controls in
compliance with California Code (Cal-Code) and
CSD-1 as an option on steam equipment when
required by state and/or local building code
requirements. Descriptions of the codes are listed
below.
Cal-Code Construction - Redundant controls in the
electrical safety circuits that, if tripped, must
manually be reset after the condition causing the trip
subsides. These controls consist of - (1) dual
function water level cycling and low level cut off
control and (1) single function low water level cut-off
control (Aux - LLCO) and a high pressure relief
switch in conjunction with a mechanical pressure
relief valve.
CSD-1 Construction - Redundant controls in the
electrical safety circuits that, if tripped, must
manually be reset after the condition causing the trip
subsides. These controls consist of - (1) dual
function water level cycling and low level cut off
control and (1) single function low water level cut-off
control (LLCO) and a high pressure relief switch in
conjunction with a mechanical pressure relief valve.
Additionally, both circuits have individual indicator
lights that will illuminate for a visual verification of
the shutdown mode.
VSX42RT SHOWN
Steam Cooking
Pressure-less steamers offer an efficient way to
produce many foods in small portions or larger
batches. Pressure-less, convection steam cooking
will steam cook fresh foods or will steam defrost and
cook frozen foods providing the maximum color,
flavor and nutritional value with the least
expenditure of energy and labor. The pressure-less
steaming compartment allows the operator to open
and close the door, anytime during a cooking cycle.
The steam supply will shut off when the door is
opened, then re-start when the door is closed.
Cal-Code and CSD-1 construction both require
operator intervention in the event of a shutdown.
CSD-1 is more informative by using indicator lights
to show which safety system was shutdown.
Model Designations
V S X XX X X
Compartment Pan Capacity
NUMBER OF
PANS PER
COMPARTMENT
DEPTH
(INCHES)
2
4.0
3
2.5
6
1.0
Pan Size 12" x 20"
Page 4 of 80
T - Tilting kettle (24 qt.) found
on 42" wide cabinet base only.
Heating System:
G - Gas
E - Electric
D - Direct
R - Regenerated
Cabinet Base Width (inches)
Pressure-less
Steamer
Vulcan
VSX SERIES STEAMERS - GENERAL
SPECIFICATIONS
Gas Steamers
LINE PRESSURE
MANIFOLD
PRESSURE
INPUT
(BTU/HR)
(INCHES W.C.)
AMPS
(INCHES W.C.)
NATURAL
LOAD
PROPANE
(WATTS)
MAX
MODEL
VSX24G
NAT.
PROP.
NAT.
PROP.
RECOMMEND
MIN
RECOMMEND
(MAX)
120V
MIN
200,000
200,000
4.0
10.0
7.0
5.0
11.0
11.0
200,000
200,000
4.0
10.0
7.0
5.0
11.0
11.0
240,000
240,000
4.0
10.0
7.0
5.0
11.0
11.0
200,000
200,000
4.0
10.0
7.0
5.0
11.0
11.0
240,000
240,000
4.0
10.0
7.0
5.0
11.0
11.0
60HZ
VSX36G
VSX42GT
360
3.0
360
3.0
360
3.0
14.0
Electric Steamers
AMPERAGE
1 PHASE
MODEL
VSX24E
VSX36E
TOTAL
KW
24*
3 PHASE
208V 240V 208V 240V 480V 220/380V & 240/415V
116
100
67
58
29
34
24*
67
58
29
34
36
100
87
44
50
42
117
116
58
67
48
VSX42ET
3 PHASE - 4 WIRE
24*
67
58
29
34
36
100
87
44
50
*std
Steam Supply
Dry steam must be provided to the steamer. If the steam is heavy with condensate, a Ball Float Trap must be
used in the line and plumbed in before the pressure reducing valve. To ensure rapid heat up of heavy cold loads,
the steam supply line must be sized to maintain pressure as outlined below.
DIRECT STEAM
STEAMERS
REGENERATED STEAM
STEAMERS
(POTABLE)
(*NON-POTABLE)
Supply Pressure
15 psi (max.)
15 psi (max.)
Flow Rate
100 lb. per hour total
(min.)
125 lb. per hour total
(min.)
Pressure Reducing
Valve Output
10 psi (furnished)
set accordingly for good
steam generation but no
higher than 15 psi.
(furnished)
*Potable steam is not required for regenerated models but could be used.
Page 5 of 80
VSX SERIES STEAMERS - OPERATION
Water Supply
WATER CONDITIONING
Supply pressure should be
In line strainer for supply line
Supply connection
Total dissolved solids (TDS)*
Total alkalinity
Silica
Chloride
PH factor
(*17.1 ppm = 1 grain of
20-80 psig
(Not Supplied)
cold
less than 60 ppm
less than 20 ppm
less than 13 ppm
less than 30 ppm
7 to 8
hardness)
TOOLS
This causes several problems:
Standard
1.
Reduce the heat transfer efficiency of the
heating system.
Volt-Ohm-Meter (VOM) with AC current tester.
2.
Cause premature failure of Electric heaters.
(Any quality VOM with a sensitivity of at least
20,000 ohms per volt can be used)
3.
Water level probes will give false readings.
4.
Thermostat bulbs will sense temperature
incorrectly.
Standard set of hand tools.
Gas leak checking equipment.
Gas Pressure Manometer
These problems are common to any manufacturer's
steamer regardless of design, but they can all be
prevented by furnishing the boiler with soft water.
Vulcan recommends the water contain less than
60ppm of “total dissolved solids” (TDS) and have a
PH factor between 7 to 8. These water properties
can be achieved by using a properly maintained
water softener.
Special
Furnishing the boiler with soft water to reduce scale
formation is important. Scale formation will reduce
steam output, cause premature component failure,
and shorten equipment life. Most water supplies
contain scale producing minerals such as Calcium
and Magnesium. As steam is generated, the
minerals remain and dissolve into the water. As the
concentration of these minerals increases past a
certain point, they precipitate from the water and
coat the inside of the boiler, heating elements,
thermostat bulbs and water level probes. Because of
the high temperature of these surfaces, the
precipitated minerals bake onto them and become
very difficult to remove.
CLR Treatment Kit - Used to remove
Calcium/Lime/Rust from a boiler (Contact
Vulcan Authorized Service Centers ).
Adaptor to test thermocouple closed circuit
voltages (DC) on gas models with manual
ignition (purchase locally).
NOTE: Adaptors vary between manufacturers.
An example of one adaptor type is pictured
below.
Other chemical properties in water supplies can also
affect good steam generation and vary from within
each state and locality.
The water level probes in the boiler use ions in the
water to detect the water level. Do not use fully
demineralized or de-ionized water since it is "non
conductive" and the water level can not be detected.
NOTE: The use of strainers, or filters will not
remove minerals from the water.
Vulcan recommends that a local water treatment
specialist be consulted before the installation of any
steam generating equipment.
Steamers that operate over a long period of time
without the benefit of a water softener, which have
developed a heavy scale build up, should be
cleaned before using a water softener.
Page 6 of 80
VSX SERIES STEAMERS - OPERATION
STEAMER OPERATION
WARNING: THE STEAMER AND ITS PARTS ARE HOT. USE CARE WHEN OPERATING, CLEANING OR
SERVICING THE STEAMER. THE COOKING COMPARTMENT CONTAINS LIVE STEAM. STAY CLEAR
WHEN OPENING EACH DOOR.
B.
CABINET BASE BOILERS
Ensure that all utility connections to the steamer
have been made and are turned on.
On models that are Cal-Code/CSD-1 equipped,
amber colored lights for Hi pressure and low water
level will illuminate and stay on until the boiler is full
and the manual reset switch pressed.
Gas Powered Steam Boiler
1.
Open the cabinet door and turn main power
switch ON. The red light will illuminate, water
will begin filling the boiler and the blowdown
solenoid valve will close. The boiler should fill,
in four to eleven minutes. Observe water level
gauge glass to verify that water is in boiler and
that the level in the gauge glass is about half
full. Both valves on gauge glass assembly must
be open to fill the gauge. Older models
equipped with a manual “ball” type blowdown
valve must be closed for the boiler to fill. The
cycling pressure switch will maintain the proper
steam pressure in the boiler by cycling the
heating system on and off to generate steam
pressure.
A.
On Models with Manual Ignition - The
knob on the gas combination control valve
has three positions (On-Pilot-Off) for
control of main burners and pilot. Turn
knob on gas combination valve to PILOT
then depress and light pilot burner with a
lit taper. Maintain knob in depressed
position for about 30 seconds and release.
Observe that pilot burner flame stays on. If
the flame should go out, wait 5 minutes
before relighting.
Turn knob on gas combination control
valve to ON. If the water level in the boiler
has reached the minimum level, burners
will ignite and begin to heat the water in
the boiler. After approximately 15 minutes,
steam should be present for cooking
product. Observe that the boiler pressure
gauge indicates steam pressure of 8-10
psi.
Page 7 of 80
On Models with Automatic Ignition The knob on the gas combination control
valve has two positions (On-Off) for
control of main burners and pilot. For the
automatic ignition system to work, the
knob must be set in the ON position or gas
for the pilot and main burners will not flow.
Also, the ignition control module
ON/OFF/RESET switch must be in the ON
position to operate. This switch is located
on the upper left side of the electrical
control box for the ignition control module.
A red light will illuminate when the switch
is in the ON position. DO NOT ATTEMPT
TO MANUALLY LIGHT THE PILOT IN AN
AUTOMATIC TYPE IGNITION SYSTEM.
After the main power switch is turned ON
and the ignition control modules RESET
switch is in the ON position, sparking will
begin three seconds later to light the
standing pilot. If the pilot lights, a signal is
sent back through the ignition cable
indicating the presence of pilot flame and
sparking stops. If the water level in the
boiler has reached the minimum level, the
burners will ignite and begin to heat the
water in the boiler. After approximately 15
minutes, steam should be present for
cooking product. Observe that the boiler
pressure gauge indicates steam pressure
of 8-10 psi. If a pilot flame is not
established immediately, sparking will
continue for 90 seconds. After that
duration, the ignition control module will
lock out and needs to be reset to start the
pilot and burner lighting cycle again.
VSX SERIES STEAMERS - OPERATION
Electrically Powered Steam Boiler
Open the cabinet door and turn main power switch
ON. The red light will illuminate, water will begin
filling the boiler and the blowdown solenoid valve
will close. The boiler should fill, in 4 to11 minutes.
Observe water level gauge glass to verify that water
is in boiler and that the level in the gauge glass is
about half full. Both valves on gauge glass
assembly must be open to fill the gauge. Older
models equipped with a manual “ball” type
blowdown valve must be closed for the boiler to fill.
If the water level in the boiler has reached the
minimum level, the magnetic contactors will close,
the heaters will energize and begin to heat the water
in the boiler. After approximately 15 minutes, steam
should be present for cooking product. Observe that
the boiler pressure gauge indicates steam pressure
of 11-13 psi.
BOILER BLOWDOWN AND
STEAMER SHUT OFF
Turn the steamer off at least once daily and blow
down the boiler to remove sediments, scalants and
lime build-up in the boiler. Always blowdown the
boiler when it is under maximum pressure and no
steam is being used.
1.
Automatic blowdown.
A.
Newer Models - Open the cabinet door
and turn main power switch OFF. The
switches’ red light will go out, the
blowdown/drain solenoid valve will be deenergized and the boiler will begin to
drain. The cold water condenser solenoid
will continue to operate, as needed, to
condense steam and to cool the water
going into the drain.
B.
Older Models - Turn power switch OFF
and depress blowdown timer button.
Blowdown timer will operate for 4 minutes.
At the end of blowdown, turn fill switch to
ON and allow boiler to fill.
Direct Steam Powered Cooker
1.
Open the cabinet door and turn main power
switch ON.
A.
The red light on the switch will illuminate.
B.
If steam pressure is above the minimum
setting on the cooking compartment
pressure switch then the switch will close,
ready light will come ON and power to the
other controls will be supplied.
C.
2.
2.
Observe that the steam pressure gauge in
the cabinet base, indicates 10-12 psi.
Steamer is ready to cook product.
Regenerated Steam Powered Boiler
1.
Open the cabinet door and turn main power
switch ON. The pilot light will illuminate, water
will begin filling the boiler and the blowdown
solenoid valve will close. Models equipped with
a manual “ball type” blowdown valve need to
be closed for the boiler to fill. The boiler should
fill, in approximately 15 minutes. Observe
water level gauge glass to verify that water is in
boiler and that the level in the gauge glass is
about half full.
Both valves on the gauge glass assembly must
be open to fill the gauge. When the water
reaches the minimum level, the steam solenoid
valve will open, allowing steam to enter the
steam coil in the heat exchanger tank and
begin heating the water. After approximately 20
minutes, a sufficient amount of pressurized
steam should be present for cooking product.
Page 8 of 80
Manual blowdown.
A.
All Models - Turn power switch OFF. Open
blowdown valve located on the bottom
front of the cabinet base. After the boiler
has completely drained, close blowdown
valve and turn fill switch to ON and allow
boiler to fill.
VSX SERIES STEAMERS - OPERATION
COOKING COMPARTMENT
CONTROLS
When the steam pressure in the cooking
compartment manifold reaches approximately 3 psi,
the cooking compartment pressure switch closes,
suppling power to the other controls. The ready
lights will illuminate and after approximately one
minute, the steam pressure in the boiler will reach
the upper limit of 10 psi. If the pressure drops below
approximately 3 psi, the pressure switch will open,
removing power from the cooking compartment
controls.
NOTE: If a cooking timer is set immediately after
the ready light comes on, a loud clanking sound will
be heard (oil canning) and the ready lights will flash
for several seconds. This condition is caused by the
manifold pressure being on the “fringe” of the
pressure switch set point. When a cook timer is set,
the compartment steam solenoid valve opens
causing the manifold steam pressure to drop,
slightly below the pressure switch set point. At the
same time, steam pressure is still increasing in the
boiler. This opposing condition causes a pressure
“bounce” to occur but after the steam pressure
passes approximately 4 psi this condition subsides.
Under normal steam cycling pressures, this
condition will not be seen.
1.
With both timer knobs at the off position, open
the compartment doors and observe that no
steam has entered the cooking compartments,
then close the doors.
2.
Set both timer knobs at 2 minutes. The ready
lights will go off, the cooking lights will come
on, and steam will begin to enter the
compartments.
3.
After one minute, open each door and observe
that steam has ceased to enter each
compartment, cooking lights go back to ready,
and one minute is remaining on each cook
timer.
4.
Close doors and steam generation and cook
timing will resume. Observe the floor drain to
ensure that live steam from compartments is
being cooled by cold water from the cold water
condenser solenoid valve.
5.
When timer knobs reach "0", buzzers will
sound, steam generation will cease, cooking
lights will go off and ready lights will come on.
To silence buzzers, turn timer knobs to off
position.
6.
During a cooking cycle, the heating system will
cycle on and off as necessary to maintain
steam pressure in the boiler.
NOTE: On direct steam units, no steam cycling will
occur due to the regulated constant steam supplied
from the building. Steam will come on for cooking
when a cook timer is set and go off at the end of
that time.
7.
Turn power switch off to remove power from
the steamer and the red light will go out.
8.
Blowdown boiler. See “BOILER BLOWDOWN
AND STEAMER SHUT-OFF” under
“STEAMER OPERATION”.
Page 9 of 80
VSX SERIES STEAMERS - COMPONENT FUNCTION AND LOCATION
COMPONENT FUNCTION AND LOCATION
CABINET BASE BOILER
CONTROLS
Cycling Pressure Switch - controls boiler pressure
between prescribed limits by turning the heat source
on and off.
WARNING: THE STEAMER AND ITS PARTS ARE
HOT. USE CARE WHEN OPERATING, CLEANING
OR SERVICING THE STEAMER. THE COOKING
COMPARTMENTS CONTAIN LIVE STEAM. STAY
CLEAR WHEN OPENING EACH DOOR.
High Limit Pressure Switch - a switch of identical
design to the cycling pressure switch but used as a
high limit. The pressure settings are at higher and
lower limits than the cycling pressure switch in order
to turn off the heat source before the boiler pressure
reaches its limit and automatically resets after the
pressure drops below the lower limit set point.
Water Level Gauge Assembly - permits visual
confirmation that water level is being maintained in
the boiler during operation. The correct water level
is a point one-half of the height of the glass. The
manual valves at the top and bottom of this
assembly must be fully open and only closed if the
glass tube is damaged.
Observe that the water is clean and clear in the
glass tube. The appearance of extreme murkiness
in the water indicates inadequate water quality and
will cause failure of controls and the steamer.
Warranty does not cover malfunction due to poor
water conditions. Blowdown and/or clean out the
boiler as outlined in “BOILER BLOWDOWN AND
STEAMER SHUT-OFF” under “STEAMER
OPERATION” and “BOILER” under “SERVICE
PROCEDURES”.
Water Level Control and Level Sensing Probes these controls allow water to enter the boiler to fill
and maintain the proper water level. They will also
shut off the heat source to the boiler if the water
level drops too low.
The water level control works by using three
different probe lengths to monitor the water level.
The probes consist of a high level (HL), low level
(LL) and low water cut-off (LLCO). The level sensing
probes may easily be removed to inspect for lime
build up. As a rule, the condition of these devices
will indicate the overall water condition of the boiler.
Clean the probes if needed.
NOTE: Controls may not function and serious
clogging will occur if a daily blowdown procedure is
not followed.
Boiler Fill Solenoid Valve - admits water to the
boiler when demanded by the water level control to
maintain the correct water level in the boiler.
Cold Water Condenser Solenoid Valve - allows
cold water flow into the boiler blowdown drain box to
condense steam and cool the hot water before its
discharge into the drain.
Blowdown/Drain Solenoid Valve - this valve is
plumbed into the drain pipe of the boiler. Newer
steamer models will automatically blowdown when
power is turned off by using a normally open
solenoid valve. Older models can have a solenoid
valve that is activated by depressing a separate
blowdown timer button or have a manual “ball” type
valve. Daily boiler blowdown is essential to proper
operation and component life by removing sediment
and scalants that may be lodged in the chamber of
the boiler.
Strainers - a strainer is used in the water inlet line
to prevent foreign matter from becoming lodged in
the fill or cold water condenser solenoid valves and
to keep unwanted particles out of the system. A "Y"
strainer should be inserted upstream of the fill
solenoid valve.
On models using a direct steam supply, a strainer is
used in the pressure regulating valve.
Power Switch - when turned ON, power is supplied
to the controls and the steam generating process is
started in the boiler. The power switch is located on
the front of the boiler control box.
Water Inlet Valve - the water inlet valve is used to
stop water flow to the steamer when the steamer is
being serviced. Newer models will have a small
Petcock type valve while older models will be a
“ball” type valve. This valve should remain open
during normal operation.
High Limit Thermostat - a protective device that
shuts off the heat source if the boiler temperature
exceeds a specified limit. All standard models are
equipped with a surface high limit.
Descaler - hangs submerged in water inside the
boiler and is used to help control boiler surface
scaling. Two descalers are used in each boiler.
Handhole Cover Assembly - when unbolted and
removed, allows internal examination and cleaning
of boiler shell and its components if required.
Page 10 of 80
VSX SERIES STEAMERS - COMPONENT FUNCTION AND LOCATION
Pressure Gauge - indicates boiler steam pressure.
Normal operating pressures are listed below.
STEAMER
TYPE
Gas
PSI
8 -10
Electric
11 - 13
Direct
10 - 12
Regenerated
10 - 12
Drain - drains steam condensate and water from
cooking compartments and boiler.
Check Valve - On models with the delime piping
assembly option, prevents the ejection of hot water
and steam out of the delime funnel if the manual
delime fill valve were to be opened.
Delime Port Assembly - On models with the delime
piping assembly option, allows the boiler and other
internal components to easily be delimed to remove
calcium, lime and rust build up. See ”BOILER”
under “SERVICE PROCEDURES”.
Standing Pilot (Gas Boilers) - should always
remain lit to light the main burners upon a call for
heat unless the steamer will not be in use for an
extended period. If the pilot flame goes out, wait 5
minutes before relighting.
Main Burners (Gas Boilers) - heats the water in
the boiler to generate steam.
Combination Control Valve (Gas Boilers) - a gas
solenoid that opens to allow gas flow when a call for
heat is made and also regulates the manifold gas
pressure.
Pressure Regulating Valve (Direct &
Regenerated Steam) - regulates the manifold
steam pressure between 10-12 psi.
Magnetic Contactor (Electric Boilers) - when coil
is energized, supplies power to the electric heating
elements.
Heating Elements (Electric Boilers) - heats the
water in the boiler to generate steam.
Page 11 of 80
VSX SERIES STEAMERS - COMPONENT FUNCTION AND LOCATION
Page 12 of 80
VSX SERIES STEAMERS - COMPONENT FUNCTION AND LOCATION
Page 13 of 80
VSX SERIES STEAMERS - COMPONENT FUNCTION AND LOCATION
COOKING COMPARTMENT
CONTROLS
Steam Solenoid Valve - when energized, opens to
allow steam into the cooking compartment (normally
closed valve).
WARNING: THE STEAMER AND ITS PARTS ARE
HOT. USE CARE WHEN OPERATING, CLEANING
OR SERVICING THE STEAMER. THE COOKING
COMPARTMENT CONTAINS LIVE STEAM. STAY
CLEAR WHEN OPENING EACH DOOR.
Compartment Pressure Switch - supplies power to
the controls only after the steam pressure rises
above 2.3 psi to close the compartment pressure
switch. The switch remains closed as long as steam
pressure stays above 2.3 psi but will open if the
pressure drops below that setting.
The upper section of the steamer consists of two
separate cooking compartments. Each compartment
functions independently with its own set of controls.
Power is supplied to the controls only after the
steam pressure rises above 3 psi to close the
compartment pressure switch. The switch remains
closed as long as steam pressure stays above 3 psi
but will open if the pressure drops below that setting.
Ready Light (Green) - when lit, indicates steamer
is ready to cook.
Cooking Light (Red) - when lit, indicates steamer
is in a cooking cycle.
Cooking Timer - use to set desired cooking cycle
time between 0-60 minutes. When a timer is set, the
steam supply solenoid valve is energized to allow
steam into the cooking compartment but only after
the boiler has reached its operating pressure. Also,
energizes the buzzer when time expires.
Manifold Pressure Gauge - indicates the amount
of steam pressure in manifold. The intake shut-off
valve should be adjusted so manifold pressure
remains at 9 psi with both compartments on.
Steam Supply Manifold - main steam supply line
from the boiler for each cooking compartment.
Supplies steam up to the steam solenoid valve.
Intake Shut-Off Valve - main steam supply shut-off
from the boiler to the steam supply manifold. This
valve should NOT be left fully OPEN to boiler steam
supply. See “INTAKE SHUT-OFF VALVE
ADJUSTMENT (STEAM FLOW) under “SERVICE
PROCEDURES”.
Buzzer - signals end of a cook cycle, must be
turned off manually.
Door Switch - removes electrical power to the
timer.
Page 14 of 80
VSX SERIES STEAMER - SERVICE PROCEDURES
SERVICE PROCEDURES
WARNING: CERTAIN PROCEDURES IN THIS SECTION REQUIRES ELECTRICAL TEST OR
MEASUREMENTS WHILE POWER IS APPLIED TO THE MACHINE. EXERCISE EXTREME CAUTION AT ALL
TIMES. IF TEST POINTS ARE NOT EASILY ACCESSIBLE, DISCONNECT POWER, ATTACH TEST
EQUIPMENT AND REAPPLY POWER TO TEST.
NOTE: Boiler water capacities vary between seven
to nine gallons for both gas and electric models
depending on the boiler size and BTU/KW rating.
CABINET BASES
BOILER
NOTE: If deliming solution accidently comes in
contact with steamer components, lightly rinse off
with clean water.
Inspection
It is recommended that the boiler be thoroughly
inspected for excessive scale and lime build up on a
quarterly basis. In hard water areas or for units
heavily used, a more frequent interval should be
used. This inspection consists of an internal
examination and cleaning of the boiler shell, an
examination and possible replacement of the
descaler, a check of lime build up on the water level
sensing probes, and a check of all boiler controls,
including the pressure switches.
A.
Models with Blowdown Timer - Pour
deliming solution into boiler shell. Mix the
solution in accordance with the instructions
on its container. Proceed to step 9.
B.
Periodic service must be performed as outlined in
these procedures. See “WATER CONDITIONING”
under “GENERAL”.
Models without Blowdown Timer - Turn off
the incoming water supply. Turn the unit
ON to close the drain valve. Pour deliming
solution into boiler shell. Mix the solution
in accordance with the instructions on its
container. Proceed to step 9.
C.
Models with Deliming Port Assembly Before mixing and pouring deliming
solution into boiler, clean the seating
surfaces for the hand hole gasket and then
install a new gasket. Position the hand
hole plate and tighten down. Turn off the
incoming water supply. Turn the unit ON
to close the drain valve. Open the
deliming assembly valve and pour the
deliming solution into the port. Mix the
solution in accordance with the instructions
on its container. Close the deliming
assembly valve and proceed to step 10.
WARNING: READ AND FOLLOW THE
INSTRUCTIONS ON THE CLR BOTTLE. USE
PLASTIC OR RUBBER GLOVES TO AVOID SKIN
CONTACT. IF CLR LIQUID COMES IN CONTACT
WITH THE SKIN, RINSE WITH CLEAN WATER.
Clean-Out (All Boiler Models)
1.
Turn steamer OFF and drain boiler.
2.
Remove hand hole plate and gasket (top front)
from the boiler by removing the nut and clamp,
then tapping the cover lightly to free it while
holding the cover stud. This prevents the cover
from dropping into boiler.
3.
Remove old descaler retaining springs if
present.
4.
With a wire brush, or equivalent, dislodge and
remove all loose scale from boiler shell. The
loose material must be either scooped from the
boiler or flushed through the drain.
5.
Check probe canister and float valve assembly
(regenerated models) for a scale build up and
clean as necessary.
6.
Check drain hole for obstructions.
7.
Install two new descalers.
8.
Mix the deliming solution according to the
instructions for the chemical in use then add
solution to boiler.
9.
Page 15 of 80
Clean the seating surfaces for the hand hole
gasket and then Install a new gasket. Position
and tighten the hand hole plate.
VSX SERIES STEAMER - SERVICE PROCEDURES
10. Cooking compartment timers are to be in the
OFF position. Turn the boiler switch ON and
open water valve if necessary.
11. Boiler is to operate under pressure for 90
minutes or per the instructions for the chemical
in use.
12. Drain boiler by normal methods. Refill boiler
and allow heat until fully pressurized.
13. Repeat step 12 three times.
14. The steamer is now ready for normal operation.
Deliming Only
(Models with Deliming Port Assembly)
Boiler deliming should be performed on a weekly,
bi-weekly or monthly basis, depending on the quality
of the local water supply.
On steamers using a water purification system,
follow the instructions for that system to delime the
boiler. Only use the type of chemical recommended
or described in the instructions for deliming with this
type of system.
1.
Turn steamer OFF and drain boiler.
2.
Mix the deliming solution according to the
instructions for the chemical in use then add
solution to boiler.
NOTE: If deliming solution accidently comes in
contact with steamer components, lightly rinse off
with clean water.
B.
3.
4.
Drain boiler by normal methods. Refill boiler
and allow to heat up and build steam pressure.
6.
Repeat step 5 three times.
7.
Unit is now ready for normal operation.
Descaler
NOTE: Boiler water capacities vary between seven
to nine gallons for both gas and electric models
depending on the boiler size and BTU/KW rating.
A.
5.
Models with Blowdown Timer - Open
the deliming assembly valve and pour the
deliming solution into the port. Mix the
solution in accordance with the instructions
on its container. Close the deliming
assembly valve and proceed to step 3.
Models without Blowdown Timer - Turn
off the incoming water supply. Turn the
unit ON to close the drain valve. Open the
deliming assembly valve and pour the
deliming solution into the port. Mix the
solution in accordance with the instructions
on its container. Close the deliming
assembly valve and proceed to step 3.
The descaler is accessible through the hand hole
opening. It is a coiled wire wound around a solid
cylindrical core, and hangs by an open loop from the
shell's horizontal stay rod, about 4 inches from the
front of the shell. If the wire is eaten through, or if
the core of the descaler is eaten away to half its
original size, a new descaler should be installed.
To install a new descaler, stretch its wire coil so that
the descaler hangs with its core completely below
the minimum water level in the boiler, but hanging
free. The descaler must not contact the bottom of
the boiler shell, electric heating elements or the
regenerating steam coils on units so equipped.
Water Level Controls
(Low Level Cut-Off and Differential)
Solid State
1.
Ensure that water is filling the boiler.
2.
Check for correct voltage being applied to the
board.
3.
Verify the water level control board operation
as outlined in “WATER LEVEL CONTROLS”
under “ELECTRICAL OPERATION”.
Top compartments are to be in the OFF
position. Turn the boiler switch ON and open
water valve if necessary.
Boiler is to operate under pressure for 90
minutes or per the instructions for the chemical
in use.
Page 16 of 80
A.
Does the HL LED light up and the HL relay
energize to change the contact state at
power on?
B.
As the boiler fills, does the LLCO LED light
up and the LLCO relay energize to change
the contact state after the water level
reaches the LLCO probe?
VSX SERIES STEAMER - SERVICE PROCEDURES
C.
Does the HL LED go out and the HL relay
de-energize, allowing the contact state to
switch back to its starting condition after
the water level reaches the HL probe?
4.
If water is in the boiler but is not being detected
by the water level probes, the probes may need
cleaned and/or boiler delimed. See “BOILER”.
5.
After checking the above items, if the water
level control board does not appear to be
functioning as outlined, then replace the board.
6.
Check unit for proper operation.
Clean probe thoroughly, removing ALL deposits
from the insulator. Do not use an abrasive on
the insulator; use a soft cloth.
5.
Inspect through the probe socket for the
presence of water. Water must drain from the
probe housing. If in doubt, pour water into the
housing and observe that it drains quickly. If
the housing fails to drain, remove the housing
or housing cover and clean the interior
mechanically.
Water Level Gauge Assembly
Electro Mechanical
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
Loose electrical connections may prevent the heat
from coming on or may cause the boiler to overfill.
Accumulation of boiler scale on or near the sensing
probes may cause them to retain water on the
insulator surface. This may prevent the boiler from
filling or cause dry firing. Dry firing will result in
damage to heating elements or to the boiler. Verify
the water level controls operation as outlined in
“WATER LEVEL CONTROLS” under “ELECTRICAL
OPERATION”.
With the individual probe lead wire removed, check
the probes and contactors as outlined below:
1.
4.
With an ohmmeter, check the probe between
the wire connection and shell. An open circuit
should be present when the boiler is empty. If
resistance is present, remove and clean the
probes. Also check for a cracked insulator, then
reinstall probes and check. When the boiler is
full of water, a resistance reading should be
measurable between the probes and shell only.
NOTE: Actual resistance reading will depend on
water quality and probe condition.
2.
Check low level and differential water level
controls. With the power switch ON, use a
voltmeter to check the input voltage across
terminals 1 & 2. Meter should read 115V. With
the boiler empty, across terminals 9 & 10, you
should read 300 to 350V. If you do not read this
voltage, then coil is bad and contactor should
be replaced.
3.
Remove sensing probe. First remove the
bolted cover over the sensor cluster. Then
remove the wire from the probe and unscrew
the probe with a wrench. Be careful to note the
location of each probe and the number of the
wire connected to it. Incorrectly connected
wires will cause the controls to malfunction.
Close the valve at the top and at the bottom of the
gauge assembly. Unscrew the packing nuts at the
top and bottom of the glass tube. Slide the glass
tube upwards, until the bottom of the tube is clear of
the fitting and lift it out.
When reinstalling the tube, use new sealing
washers. Do not over tighten the packing nuts; it
could break the gauge glass. Check that both top
and bottom valves are fully open.
Pressure Switches (Gas and Electric Models)
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
Remove the boiler control box cover to access the
two controls. The pressure switch on the left is the
cycling or primary control; the one on the right is the
high limit control. They are identical switches,
differing only in their settings.
Turn the power ON and let the boiler come up to
pressure. After the ready light comes ON, turn one
of the cooking compartment timers on to exhaust
steam from the boiler. Observe boiler pressure
gauge readings for several cycles and compare
them with the pressure settings in the chart. If the
readings differ, adjust the pressure settings as
described below.
Two slotted and square headed adjustment screws
extend through the top of the switch case with dials
and pointers to indicate the approximate setting.
The adjustment screw directly above the dial
changes both the cut-out (off) and the cut-in (on)
points. Set it first to give the proper off setting.
Turning the screw clockwise increases the pressure.
Then set the second adjustment screw to give the
proper on setting. The pressure settings for each
switch are listed below.
Page 17 of 80
PRESSURE SETTINGS (PSI)
CYCLING
HIGH LIMIT
UNIT
ON
OFF
ON
OFF
Gas
8
10
6
15
Electric
11
13
6
15
VSX SERIES STEAMER - SERVICE PROCEDURES
High Limit Thermostat
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
Remove thermostat (bi-metallic disk type) and
inspect flat surface of thermostat for corrosion or
rust. Replace if rusted.
Clean thermostat mounting and thermostat surfaces
before remounting or replacing. A good
metal-to-metal contact is essential for proper
functioning of the thermostat. This service must be
performed at least once a year.
On gas boilers, the high limit thermostat is located
on the face of the boiler close to the sight glass on
the right side. For access, remove the small metal
cover placed over the thermostat.
On electric boilers, the high limit thermostat is
located behind the contactor box cover. On electric
boilers with two heating elements, the thermostat is
connected to one of the heating element lugs. On
electric boilers with four heating elements, the
thermostat is located between the center pair of
elements at the top of the elements.
Removing The Boiler Assembly
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
WARNING: SHUT OFF THE GAS BEFORE
SERVICING THE UNIT.
WARNING: ALL GAS JOINTS DISTURBED
DURING SERVICING MUST BE CHECKED FOR
LEAKS. CHECK WITH A SOAP AND WATER
SOLUTION (BUBBLES). DO NOT USE AN OPEN
FLAME.
A.
CHECK ALL JOINTS PRIOR TO THE
GAS VALVE (SOLENOID) BEFORE
LIGHTING UNIT.
B.
CHECK ALL JOINTS BEYOND GAS
VALVE (SOLENOID) AFTER UNIT IS LIT.
Newer Steamer Models - Blow down the boiler and
allow to cool, if necessary. Ensure that all utilities to
the steamer are off. Drain any excess water from
the boiler. Disconnect the steam supply line, power
leads and drain lines from the cooking compartment
top to the boiler base. Remove the cooking
compartment top by unscrewing the bolts holding
the cooking compartment top to the boiler base. The
bolts are located behind the small louvered access
panels on the left and right side of the steamer. Lift
the top off the boiler base and place to the side.
Remove the remaining plumbing and electrical
connections from the boiler to the controls. Remove
the bolts securing the boiler to the frame and lift it
out. Reverse procedure to install a new boiler.
Older Steamer Models - Blow down the boiler and
allow to cool, if necessary. Turn off all utilities to the
steamer and disconnect supply lines. Drain any
excess water from the boiler. Remove the screws
holding any control box that would obstruct removal
of the boiler through the front of the base.
Disconnect the 1/4 inch diameter water inlet tubing.
Disconnect the wire and conduit from the low water
cut-off probes, high limit thermostat, and the
automatic blowdown valve (if so equipped).
Uncouple the union on the steam outlet and blow
down the lines.
Remove all the screws holding the flue and flue
collector to the base. Remove the anchor screws
holding the boiler to the frame. Slide the boiler
forward. The burner box, anchored only by the
boiler, must be prevented from sliding forward with
the boiler.
Fill and Cold Water Solenoid Valves
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
Removal
1.
Turn off the water supply to the steamer.
2.
Open the base doors and remove the two
screws from the top of the boiler control box.
3.
Pull the quick connect power leads off the
solenoid valve being serviced.
4.
Disconnect the water lines for the valve being
serviced and remove the valve from the unit.
5.
Reverse procedure to install.
Disassembly
NOTE: It is recommended that the valve be
removed from the unit for cleaning to prevent
damage to the lines and fittings when the stem is
removed from the body.
1.
Remove the coil assembly from the valve stem
by lifting up on the retaining cap at the top of
the solenoid valve and sliding the metal cover
plate off.
2.
Clamp the body of the valve in a vise.
3.
Mark a scribe line on the stem nut to the valve
body for proper retightening.
Page 18 of 80
VSX SERIES STEAMER - SERVICE PROCEDURES
4.
Remove the stem locking nut to remove the
stem from the valve body.
5.
All parts are now accessible for inspection and
cleaning.
NOTE: If internal solenoid parts appear to be
damaged or worn, then replace the solenoid valve.
Do not reuse damaged or worn parts. No internal
solenoid parts are available as a service
replacement. Pay careful attention to proper
orientation and placement of parts during
reassembly.
A.
Check rubber seal on bottom of plunger.
B.
Check plunger spring.
C.
Check O-ring in valve body.
D.
Check ports in valve body.
Newer steamer models use a plunger type rod that
raises and lowers to permit steam/water flow out of
boiler. If debris has accumulated around the water
orifice, the plunger may not seat properly to close
off the opening. If this symptom is suspect, remove
the solenoid as outlined in “FILL AND COLD
WATER SOLENOID VALVES”. Remove any debris
found on sealing surfaces, reassemble and install. If
the solenoid valve still does not function properly,
replace it with a new valve and check for proper
operation.
Older steamer models have a movable blade and
when closed, the blade reacts as a guillotine that
should be free to move fully down into the valve
pocket (projection at bottom of valve) so that the
pierced hole in the blade aligns perfectly with the
body opening. If debris has accumulated in the
bottom of the valve pocket, then the blade will not
move into the pocket completely. If this symptom is
suspect, remove the solenoid as outlined in “FILL
AND COLD WATER SOLENOID VALVES”.
NOTE: On this valve body, remove the two
assembly bolts holding the brass body together and
remove the loose internal parts. Remove any debris
found on sealing surfaces, reassemble and install. If
the solenoid valve still does not function properly,
replace it with a new valve and check for proper
operation.
6.
Reverse procedure to install.
Blowdown Solenoid Valve Does Not Drain
Water Not Being Supplied to Boiler
Turn the steamer on. Check that water supply is
available to the steamer. After approximately 10
minutes, if no water is observed in the water level
gauge sight glass, then check for a problem with the
water solenoid valve or water level control probe.
If your steamer has an automatic blowdown drain
valve.
Older Models - when the blowdown timer button is
pressed, the boiler blowdown valve opens. If your
steamer has a manual blowdown drain valve, close
the valve.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
Newer Models - are equipped with normally open
solenoid valves that close when energized by the
main power switch. When the main power switch is
turned off, the solenoid valve is de-energized and
the boiler blowdown valve re-opens.
Scalants may be covering the water level control
probe giving a false indication of a sufficient water
level in the boiler. Detach, remove and thoroughly
clean the water level probe and canister assembly
to remove scalants and lime build up. This condition
indicates extremely poor water quality being
supplied to the boiler and/or boiler clean out/and
deliming has not been performed. The water
condition must be cleared up immediately with a
proper water conditioner to avoid further problems
with the steamer. Replace the water level probes
and canister assembly. Perform a boiler clean-out
and deliming procedure. See “BOILER”.
The water contained in the boiler, being under
pressure, should be blown through this valve and be
noticeably visible exhausting out the steamer drain.
Water may be draining through an open boiler
blowdown solenoid valve as quickly as it’s fed to the
boiler. Loose wiring, a burned out coil or particles of
scale trapped in the valve seat may prevent the
valve from closing.
If the blowdown operation appears to function
sluggishly or not at all, considerable scalants may
be lodged in the drain pipe and/or the valve.
Disconnect the valve from the drain line and inspect
both the valve and the drain pipe fixed to the boiler.
If considerable scalants or lime build up is apparent,
then not only the valve, but also the boiler and water
level control must be thoroughly cleaned. See “FILL
AND COLD WATER SOLENOID VALVES” for a
cleaning procedure of a solenoid valve and
"BOILER” for a cleaning procedure of the boiler.
Page 19 of 80
VSX SERIES STEAMER - SERVICE PROCEDURES
D.
Steamer Achieves Pressure Slower Than Normal
If the boiler requires more than 15 minutes (20
minutes for regenerated models) to achieve normal
operating pressure as listed in below, then check the
following conditions.
NORMAL OPERATING
STEAM PRESSURES
1.
RANGE (PSI)
Gas
8 - 10
Electric
11 - 13
Direct
10 - 12
Regenerated
10 - 12
3.
All Models (With Boiler)
A.
2.
UNIT
A heavy build-up of scalants has possibly
coated the interior of the boiler. The
insulating effect of the scalants hampers
heat transfer. Unbolt and remove the hand
hole cover plate and gasket assembly.
Examine interior of boiler and if scalants
and/or lime build up is apparent, perform a
boiler clean-out and deliming procedure.
See “BOILER”. If considerable scalants
are evident, then both the boiler blowdown
solenoid valve and the water level control
must also be examined.
4.
Gas Models
A.
B.
C.
Low incoming gas pressure causes
reduced BTU output. Check incoming line
and manifold gas pressures as outlined in
“MANIFOLD PRESSURE ADJUSTMENT.”
5.
Gas combination control valve
malfunction. Check incoming and manifold
gas pressures as outlined in “MANIFOLD
PRESSURE ADJUSTMENT.” If pressure
adjustments are made and manifold
pressure remains low, replace the
combination valve and test unit for proper
operation.
Gas burner ports clogged or obstruction
around air shutter. After a period of time,
gas burners can accumulate carbon in
their ports or become clogged by food and
grease debris from kitchen cleaning,
restricting performance. To clean burners,
remove them from burner box and boil in
water for 10 -15 minutes to dislodge clog.
Clean-out any remaining debris from the
gas ports using a wire brush, scribe or pic
type metal instrument. Remove any other
foreign objects that appear to be
obstructing the gas ports or air shutters.
Page 20 of 80
Gas orifice clogged or obstructed around
air shutter. It is possible for debris to
become lodged in the small gas orifice
opening over time. Clean-out the gas
orifice using a round metal instrument of
the same hole diameter or slightly smaller.
Clean as needed. If clogging reappears,
the orifice should be removed, cleaned
and reinstalled. Remove any other foreign
objects that appear to be obstructing the
gas orifice or air shutters.
Electric Models
A.
Heavy scale build up on heating element
causes reduced heating.
B.
One or more electric heating elements
malfunctioning.
C.
One or more magnetic contactors not
pulling in, to power heating elements.
D.
If unit operates under three phase power,
then one of the phases might be lost.
Direct Steam Models
A.
Building steam supply pressure low.
B.
Cooking compartment steam solenoid
valve malfunction.
C.
Steam pressure regulator adjusted too
low.
D.
Clogging in the steam line reduces steam
supply.
Regenerated (Steam Coil) Steamers
A.
Heavy scale build up inside copper steam
coil.
B.
Building steam supply pressure low
C.
Cooking compartment steam solenoid
valve malfunction.
VSX SERIES STEAMER - SERVICE PROCEDURES
Inlet Water Strainer
The in-line Y strainer should be located upstream of
the fill valve solenoid. Unscrew the cap from the
body on the leg of the Y that should be pointing
downwards toward the floor. Remove the screen
and any foreign particles trapped in the opening.
Rinse the screen thoroughly to remove accumulated
debris and replace the screen in the valve body. If
screen can not be thoroughly cleaned, replace it
with a new one. Reinstall the cap and ensure that
the Y strainer is positioned with the cap pointing
downward to catch debris.
NOTE: If adjustments in gas or pilot pressure
settings are made, always replace the adjustment
cover screw to assure proper gas control operation.
The pressure regulating valve strainer will become
clogged if dirty steam lines are connected to direct
steam models. Remove the hex nut on the bottom
of the pressure regulating valve to clean the strainer
and valve seat.
GAS MODELS
Pilot, Thermocouple or Main Burners
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
WARNING: SHUT OFF THE GAS BEFORE
SERVICING THE UNIT.
The pilot thermocouple supplies a millivolt signal
(DC) to an internal solenoid valve on the gas
combination control valve when heated. This
solenoid valve is designed to shut off the gas flow to
the pilot and main burners in case of a malfunction
in the system. When energized by the thermocouple
voltage, the valve is held in the open position to
permit gas flow. The pilot burner flame is controlled
by an adjustable needle valve located under a small
cap screw on the combination control valve.
When experiencing nuisance pilot outages, visually
check pilot flame for the proper contact on
thermocouple and the flame color. Also, check to
see that unusually strong floor drafts are not
interfering with proper heating of the thermocouple
by the pilot flame.
The pilot flame should be a steady blue flame that
envelopes the thermocouple tip. The flame should
be about one inch long with half its length extending
beyond the outer edges of the pilot shield. If the pilot
flame does not appear to be this length and color,
then an adjustment is necessary. See the diagram
below for an example of un satisfactory pilot flames.
Turn clockwise to decrease pilot flame and
counterclockwise to increase.
If adjustment does not result in a pilot flame of
proper size, then gas might not be flowing properly
to the pilot. Check for a plugged pilot orifice, a
kinked or plugged pilot gas supply tube and for low
gas supply pressure. The pilot operates unregulated
at gas supply pressures while the pressure regulator
in the combination control valve regulates pressure
to the main burners only. Visually check the
thermocouple tip (hot end) and tube lead for kinks or
pinches that might be causing a short between the
tube and the wire inside. Also, check the threaded
connector tip for corrosion, tarnish or dirt which can
cause a poor connection. If the thermocouple shows
either of these signs, it should be replaced with a
new one.
NOTE: The connection of the tubing from the
thermocouple tip to the control valve is an electrical
connection and must be clean. Do not use any
sealing compound on the threads or over tighten the
threaded connection. Finger tighten the nut plus 1/4
turn with a wrench. Over tightening the nut could
crush the insulator, shorting the thermocouple.
If the pilot flame is correct and there are no drafts,
then the problem is in the thermocouple output
voltage or the gas solenoid valve in the combination
control.
Page 21 of 80
VSX SERIES STEAMER - SERVICE PROCEDURES
Check the thermocouple output voltage (DC
millivolts) with a VOM. If a meter is not available,
replace the thermocouple with a new one and
recheck operation. First, take a closed circuit
reading (adaptor required) with the pilot on. Next,
take an open circuit reading by disconnecting the
thermocouple tube from the valve and connecting
meter leads to the tube and threaded end. Manually
press and hold down OFF/PILOT/ON knob and light
the pilot. Allow the pilot to heat the thermocouple for
one to two minutes and compare the readings with
the chart below.
High voltage is sent from terminal nine to the spark
electrode and an output of 24 volts is sent from
terminals two and three to the pilot coil in the
combination valve, allowing gas to flow to the pilot.
The sparking will continue for 90 seconds or until
the flame sensor has confirmed that an adequate
pilot flame is present.
Once the pilot flame is confirmed, a 24 volt output
from terminal one will be sent, allowing the cycling
coil of the combination valve to operate at the
request of the cycling pressure switch.
THERMOCOUPLE
MV
READINGS
CLOSED
CIRCUIT
Typical
15
Range
10 - 20
OPEN
CIRCUIT
20 - 35
If either of the readings is less than the minimum or
thermocouple is not operating as described, replace
the thermocouple. To replace, remove the pilot
assembly by disconnecting thermocouple and pilot
gas supply tubing from the combination control
valve and remove the two screws holding the pilot
to its bracket. Replace the thermocouple or pilot
assembly and check for proper operation. If after
replacing thermocouple, the pilot or main burners
are still not functioning properly, then a problem in
the gas combination control valve exists as well.
Replace the combination control valve as outlined in
“GAS COMBINATION CONTROL VALVE
REPLACEMENT” then check for proper operation.
Terminals:
1.
Main Voltage - 24V AC will be present on
terminal #1 with the pilot sensing electrode
sensing an adequate pilot fame. This output will
remain present as long as the pilot flame
remains adequate.
2.
Common (MV/PV).
3.
Pilot Voltage - 24V AC will be present on
terminal #3 at the instant an input voltage is
supplied to the module. This voltage will
remain present on terminal #3 providing an
adequate pilot flame is established within 90
seconds. In the event that an adequate pilot
flame is not established within 90 seconds this
output voltage will drop out.
4.
Ground (burner).
5.
Ground (24VAC Neutral).
Automatic Ignition Systems
6.
24V AC Input.
When the main power switch is turned ON and the
ignition control modules reset switch is in the ON
position, the ignition control module is energized
with 24 volts between terminals five and six.
7.
High Voltage to spark electrode (The pilot
flame current is sensed by the Ignitor Module
via the spark electrode high voltage wire and
terminal #9).
NOTE: Gas combination control valves are not
serviceable and should not be disassembled. Once
you have isolated the problem to this control,
replace it. Do not attempt to repair the assembly.
The main burners are lanced port steel burners (5 or
7 burners, depending on the unit) and have
adjustable air shutters. Fixed orifice type hoods are
used to establish the gas flow to each burner. Set
each burner air shutter opening just large enough to
eliminate any yellow tip in the burner flame.
To remove main burners, lift burner and slide it to
the rear just enough to clear the gas orifice hood.
Lower the front end of burner and bring it forward
under the manifold pipe. When reinstalling burners,
ensure that locating pin is in the hole for proper
positioning and to prevent burner from rolling over.
Page 22 of 80
VSX SERIES STEAMER - SERVICE PROCEDURES
C.
Spark Ignition Control Test
1.
2.
If the ignition control module does not appear
to be sparking to ignite gas, perform the
following checks.
A.
Check to ensure that all electrical terminal
connections on the ignition control module
and the ignitor are clean and tight.
B.
Verify that the ignition control module and
the ignitor have good ground wire
connections. The ignitor mounting bracket
should have good metal to metal contact
to its mounting surface.
C.
Turn the main power switch ON. Turn the
ignition control modules re-set switch OFF
then ON.
D.
Check for 24VAC output on the ignition
control module transformer.
1)
If 24VAC is present then replace
ignition control module and re-test.
2)
If 24VAC is not present then ensure
that transformer is receiving 120VAC
input. If ignition control module
transformer is receiving proper
voltage, then replace ignition control
module transformer and re-test.
If the ignition control module and transformer
are functioning properly, then check the
following ignitor conditions.
A.
The gap between the spark probe and the
ground clip should be approximately 1/8
inch. If the gap appears to be excessive or
poor sparking is occurring, remove the
electronic ignition pilot and adjust gap.
3.
Check the ignition cable for tightness or
damaged insulation.
Check unit for proper operation.
Gas Combination Control Valve Replacement
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
WARNING: SHUT OFF THE GAS SUPPLY
BEFORE SERVICING THE UNIT.
WARNING: ALL GAS JOINTS DISTURBED
DURING SERVICING MUST BE CHECKED FOR
LEAKS. CHECK WITH A SOAP AND WATER
SOLUTION (BUBBLES). DO NOT USE AN OPEN
FLAME.
A.
CHECK ALL JOINTS PRIOR TO THE
GAS VALVE (SOLENOID) BEFORE
LIGHTING UNIT.
B.
CHECK ALL JOINTS BEYOND GAS
VALVE (SOLENOID) AFTER UNIT IS LIT.
NOTE: Gas combination control valves are not
serviceable and should not be disassembled. Once
the problem has been isolated to this control,
replace it. Do not attempt to repair the assembly.
Remove the two screws on the control box cover.
Disconnect electrical supply wires and conduit
running to the combination control valve.
Disconnect the thermocouple lead and pilot gas
supply tube from control and pipe connections on
each side of the control. Reverse procedure to
install and check unit for proper operation.
Manifold Pressure Adjustment
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
WARNING: SHUT OFF THE GAS SUPPLY
BEFORE SERVICING THE UNIT.
B.
Inspect the ceramic flame rod insulator for
cracks or evidence of exposure to extreme
heat, which can permit leakage to ground.
If either of these conditions exist, then
replace the pilot ignitor assembly.
1.
Open the front cabinet doors and turn the Gas
Combination Control Valve OFF.
2.
To measure the manifold pressure, remove the
1/8 inch NPT plug (pressure tap) on the outlet
side of the valve and attach a manometer.
3.
Turn the gas combination control valve and the
main power switch to ON.
4.
Observe the manometer pressure reading and
compare to the pressure chart near the end of
this procedure.
Page 23 of 80
VSX SERIES STEAMER - SERVICE PROCEDURES
A.
B.
5.
If other appliances are connected to the
same gas line, turn them all ON and check
manometer pressure reading again. If a
pressure drop of ½ inch water column or
more is observed, then the gas supply
needs to be checked by the gas line
installer or the local gas company for
adequate sizing.
If no other gas appliances are connected
to the gas line and the manifold pressure
still requires adjustment, proceed to step
5.
7.
Once the correct pressure has been set, turn
the power switch OFF, replace the adjustment
screw cap and 1/8 inch NPT plug (pressure tap)
on the outlet side of the valve.
8.
Check unit for proper operation.
ELECTRIC MODELS
Magnetic Contactor
A.
To increase pressure, turn the screw
clockwise.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
B.
To decrease pressure, turn the screw
counterclockwise.
The contactor can be serviced by removing the
cover of the contactor box.
Remove the adjustment screw cap to access
the pressure adjustment screw.
A noisy contactor (hum or chatter) is generally due
to enough dust or dirt on the armature pole faces or
around the armature core that the magnet coil
cannot pull the armature into a completely sealed
position. This can usually be corrected by blowing or
wiping the pole faces clean. To inspect electrical
contacts, remove cover at top of contactor by
removing two screws which hold it in place. Replace
contactor if the electrical contacts appear to be
pitted or burned.
Heating Element
WARNING: THE FOLLOWING STEPS REQUIRE
POWER TO BE APPLIED TO THE UNIT DURING
THE TEST. USE EXTREME CAUTION AT ALL
TIMES.
1.
NOTE: Accurate gas pressure adjustments can only
be made with the gas ON and the burner lit.
6.
After the burner lights, set the pressure as
outlined below:
Measure the voltage at the heating element
terminals and verify it against the data plate
voltage.
A.
If voltage is correct then proceed to step 2.
B.
If voltage is not correct, check the
following:
1)
PRESSURE READINGS
(INCHES W.C.)
LINE
GAS TYPE
Natural
MANIFOLD
4.0
RECOMMENDED
MIN
7.0
5.0
MAX
14
Propane
10.0
11.0
2.
11.0
* If the incoming line pressure is less than the
minimum stated, then the manifold pressure can not
be set correctly.
Page 24 of 80
Voltage supply to the unit.
a.
Fuses or breaker blown.
b.
Power to contactor coils.
c.
Contactors not pulling in.
(Mechanical)
Check current draw (amps) through the heating
element lead wires. See table below for
proper values.
A.
If current draw is correct then heating
element is ok.
B.
If current draw is not correct then proceed
to step 3.
VSX SERIES STEAMER - SERVICE PROCEDURES
3.
Remove the lead wires from the heating element and check the element resistance using a VOM.
A.
If resistance readings are not correct, replace heating element.
1)
To replace an element, drain water from boiler shell.
2)
Remove cover of contactor box, remove electric wires to that element's terminals, remove bolts
through flange of element and pull element forward.
NOTE: When replacing an element, always use a new gasket and ensure that the flange and tube surfaces which
contact the gasket are clean. If removed element shows a pronounced scale build-up on its heating tubes, the
other elements should be removed and mechanically cleaned to remove the scale. This will prolong their life. DO
NOT immerse elements in a chemical solution to descale.
4.
After new element is installed, check unit for proper operation.
TOTAL
VOLTAGE
KW
AMPERAGE
PER LINE
NUMBER
OF
ELEMENTS
KW
PER
ELEMENT
1 PH
3 PH
RESISTANCE
PER
ELEMENT
(OHMS)
208
18
2
9
87
50
14.42
240
18
2
9
75
44
19.20
480
18
2
9
22
76.80
*220/380
240/415
18
2
9
25
19.20
208
24
4
6
116
68
21.63
240
24
4
6
100
58
28.80
480
24
4
6
29
115.20
*220/380
240/415
24
4
6
57.8
28.80
208
24
2
12
116
68
10.82
240
24
2
12
100
58
14.40
480
24
2
12
29
57.60
*220/380
240/415
24
2
12
34
14.40
208
36
4
9
100
14.42
240
36
4
9
87
19.20
480
36
4
9
44
76.80
*220/380
240/415
36
4
9
50
19.20
208
42
4
10.5
117
12.36
240
48
4
12
116
14.40
480
48
4
12
58
57.60
*220/380
240/415
48
4
12
67
14.40
NOTES:
1. Values in the table are nominal. Tolerance is +/-10 %.
2.
Asterisk (*) indicates 3 phase/4wire.
3.
Each heater has three internal elements.
4.
6.0 KW heaters used on older models and included for reference.
Page 25 of 80
VSX SERIES STEAMER - SERVICE PROCEDURES
DIRECT STEAM MODELS
These models consist of a pressure regulator and
gauge that run off a buildings potable steam supply.
The maximum input pressure to the regulator should
be 15 psi. Incoming power (120VAC) for the
compartment controls is supplied from a junction
box in the base. See “COOKING COMPARTMENT
CONTROLS” under “COMPONENT FUNCTION
AND LOCATION” and “COOKING
COMPARTMENT” under “SERVICE
PROCEDURES”.
1.
Ensure that voltage is reaching control circuit
through compartment pressure switch, when
the main power switch is turned ON.
2.
On electric heat models with a transformer,
check step down transformer for proper
operation.
3.
Check door switch for proper operation.
4.
Check cooking timer function and contact
position. See “SCHEMATIC ALL MODELS COMPARTMENT CONTROLS” under
“ELECTRICAL OPERATION”.
5.
Check that timer motor operates when
connected to power. If a problem is found in
timer, replace it, do not take timer apart.
6.
Check wiring for damaged insulation. (no short
circuit)
7.
Check that all connections and terminals are
securely fastened. (no open circuits)
8.
Check that all connections are made according
to compartment control wiring diagram.
REGENERATED STEAM MODELS (STEAM COIL)
The steam coils are intended for use at a steam
supply pressure of 15 psi maximum. A pressure
regulating valve is available as optional equipment
for steamers where the steam supply pressure
exceeds 15 psi. The regulator used will be of the
adjustable type and should be set for a discharge
pressure of 15 psi. This pressure can be monitored
by the supplied pressure gauge. The regulator
should be set ONLY when steam is flowing (steam
solenoid valve is open). If steam is heavy with
condensate, install a ball float trap in the steam line
before the pressure regulating valve.
To remove a steam coil, disconnect union in steam
supply line to the coils and in the condensate
discharge line from the coils. Remove header that
supplies steam to coils by disconnecting union at
each coil. In same way, remove coil condensate
collection header. Remove four bolts clamping each
coil flange in place and pull coil forward. Use a new
flange gasket when replacing coil. The faces that
mate with gasket must be clean.
Turn steamer power switch ON, allowing steam
generation and, consequently, pressure to rise to
normal operating level and then turn power switch
OFF for a final purging of boiler and steam supply
lines. Steamer is now ready for use.
Steam Supply Solenoid - Each cooking
compartment is supplied steam by its own individual
steam supply solenoid. These solenoid valves are a
standard type and can be disassembled for
cleaning.
1.
Newer Steamer Models - The magnetic coil of
a solenoid valve is removed from the valve by
removing the snap catch at the top. Unions or
compression fittings are provided to allow easy
removal of the valve bodies. The solenoid
valves must be removed for disassembly as
outlined under “FILL AND COLD WATER
SOLENOID VALVES”.
2.
Older Steamer Models - Remove the two
screws and remove the inlet part of the body,
the compression spring on the back of it and
the plastic part now exposed. Unscrew and
remove the plunger tube. Remove the plunger
(the valve blade is pinned to the lower end of
the plunger). The plastic seat at the exhaust
side of the valve blade may now be removed
from the body. This is a direct acting valve.
COOKING COMPARTMENT
WARNING: CERTAIN PROCEDURES IN THIS
SECTION REQUIRE ELECTRICAL TEST OR
MEASUREMENTS WHILE POWER IS APPLIED
TO THE MACHINE. EXERCISE EXTREME
CAUTION AT ALL TIMES. IF TEST POINTS ARE
NOT EASILY ACCESSIBLE, DISCONNECT
POWER, ATTACH TEST EQUIPMENT AND
REAPPLY POWER TO TEST.
Controls
For access to compartment controls, remove the
right side compartment panel.
Check for failure of the control circuit in the
following order:
Page 26 of 80
The blade must be clean and the blade mating
surfaces of the plastic seat members must be
flat and undamaged. The plunger and plunger
tube must be clean and the plunger must slide
freely in the tube. The compression spring
which fits in the hole in the top of the plunger
must be clean and move freely.
VSX SERIES STEAMER - SERVICE PROCEDURES
Water Accumulating in Compartment - Water
accumulation on the bottom of the cooking
compartment(s) is primarily condensed steam.
Failure to drain out quickly and completely, may be
due to clogged debris in the compartment drain
screen. Pull screen straight out and thoroughly
clean, then replace. Failure to drain completely may
also be due to improper leveling of the steamer.
8.
Monitor gauge reading 1 to 2 cycles to ensure
pressure is set correctly.
9.
Once the valve is set, turn both cooking timers
off and reinstall right side control panel.
Cooking Cycle Cannot Be Activated - Inspect all
wire terminations to ensure they are positive and
secure before assuming any other problem. When
the power switch on boiler control box is ON, set the
timer knob to 2 minutes. Both READY lights should
go off, COOKING lights should come on and steam
should be entering both compartments.
1.
Remove top cover.
2.
Open the door.
3.
Pull hinge rod up.
4.
Reverse the procedure to install, making sure
the door bushings are in place.
Intake Shut-Off Valve Adjustment (Steam Flow)
1.
Remove right side control panel.
2.
Open the intake shut-off valve completely.
3.
If the steamer ready light is on, then proceed to
step 5.
4.
If the boiler is off, then turn main power switch
ON and allow boiler to heat up until steamer
ready light comes on. Turn both cooking timers
on and allow boiler to cycle 2 to 3 times, then
proceed to step 6.
DOOR
Removal
Gasket
1.
Open the door.
2.
Remove screws from the gasket plate.
3.
Pull the gasket plate out from the door housing
and remove the gasket.
4.
Position the new gasket on the gasket plate
and reverse the procedure to install. Adjust the
door as outlined in “SEALING ADJUSTMENT
under "DOOR".
NOTE: Do not over tighten gasket plate screws as
this will compress the gasket excessively and
interfere with proper door sealing.
NOTE: Damage to the gasket sealing surface, such
as nicks or cuts, will cause steam leakage.
5.
Turn both cooking timers on.
6.
Monitor the boiler until heat source turns off.
7.
At that time, adjust the intake shut-off valve
until the manifold pressure gauge reads 9 ±1
psi. The valve setting should be made while the
boiler pressure is at the upper cycling limit.
Page 27 of 80
VSX SERIES STEAMER - SERVICE PROCEDURES
Sealing Adjustment
1.
Check the door gasket quality. If damaged or
worn, replace as outlined in “REMOVAL” under
“DOOR”.
2.
Loosen screws until the screw heads no longer
touch the gasket plate.
3.
Tighten screws until screw head touches gasket
plate and at that point begin counting turns.
4.
Tighten all screws approximately two turns.
5.
Close the door and check unit for proper
operation.
6.
If necessary, tighten all screws an additional ½
turn and repeat step 5.
7.
Repeat step 6 until the door closes properly
and no steam leaks are seen around the gasket
seal.
NOTE: When installing the spacers, the smaller
diameter fits into the slot in the door and the latch
lever must rest on top of the handle latch screw.
Handle
1.
Open the door.
2.
Remove screws from the top and bottom of the
door.
5.
3.
Pull the inner door panel out from the door
housing with the gasket plate and gasket still
attached.
1.
Open the door.
2.
Remove screws from the top and bottom of the
door.
3.
Pull the inner door panel out from the door
housing with the gasket plate and gasket still
attached.
4.
Remove the screws from the side edge of the
door that secure the latch mechanism and
remove the latch from the door.
Reverse procedure to install.
Latch Assembly
NOTE: When installing, the latch lever must rest on
top of the handle latch screw.
5.
4.
Remove the nuts and spacers from the handle
screws and remove the handle from the door.
Page 28 of 80
Reverse procedure to install.
VSX SERIES STEAMER - SERVICE PROCEDURES
Latch Adjustment
3.
Open the door and check the strikers’ slot for
horizontal alignment. The slot on the striker
must be kept horizontal in order for the door
latch to catch it properly and latch.
4.
Once the proper slot alignment has been set,
hold the striker close to its base using a rag and
vise grips, then tighten the striker nut. Be
careful not to damage the striker slot when
tightening or door may not latch properly.
Should the cooker door jam and can not be opened,
DO NOT FORCE OR PRY the door as damage will
occur.
First, try lifting up on the bottom of the door at the
handle end to disengage the latch. If that does not
work, remove the right side panel.
The striker that catches on the door latch is located
behind the front face of the cooking cavity. Remove
the nut from the striker and this will release it from
the panel.
Once the nut and washer have been removed, door
will open freely.
Remove any burrs on the striker that may cause the
latch to stick. Reinstall the striker and adjust, so
door will not jam.
NOTE: Do not over tighten as the striker will begin
to turn and change alignment.
To adjust:
1.
Reinstall the striker with the slot pointing
upwards and hand tighten nut only.
2.
Close the door to center the striker in the oval
mounting hole.
Page 29 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
ELECTRICAL OPERATION
WATER LEVEL CONTROLS
Solid State Low level Cut-Off & Differential Control
The steamer is equipped with three water level
sensing probes (high, low and low level cut-off) and
a single water level control board. The water level
control board performs two functions: 1) Provide low
level cut-off protection to shut off the heat source in
case the water level drops below the low level cutoff (LLCO) probe. 2) Perform as a differential level
control to maintain the water level between the low
and high water level probes.
When the water level drops below the low level (LL)
probe, power is removed from the inverse latching
relay, the HL relay energizes through ILR-2 and HL
contacts change state. The fill solenoid is energized
through HL-3 to refill the boiler and the HL LED is lit.
The HL relay and LED will toggle ON and OFF
during a cooking cycle as needed.
The water level control (WLC) has input voltage
(120VAC) across terminals 11 and 12 which powers
the primary side of the transformer. On one side of
the transformer secondary, power is provided to the
control by a series path through chassis ground
(terminal 10). The other side of the transformer
secondary (12VAC) is attached to the probe that
directs power to the other side of the internal relays
(LLCO, HL and ILR). As water enters the boiler, it
becomes part of the water level control’s circuit.
When the water level in the boiler reaches a probe,
that circuit is completed.
The inverse latching relay of the board is deenergized, leaving the ILR-1 (N.O.) and ILR-2 (N.C.)
contacts in their shelf state.
When the main power switch is turned ON, power is
supplied to the WLC board which energizes the high
level (HL) relay and illuminates the HL relay LED.
With the HL-3 contacts closed, the boiler fill
solenoid is energized and water begins filling the
boiler.
When the water level reaches the low level cut-off
(LLCO) probe, the LLCO relay is energized and
illuminates the LLCO LED. With the LLCO-2
contacts closed the heat source is then energized.
The LLCO relay will remain energized and its LED
will stay lit until the water level in the boiler drops
below the LLCO probe.
When the water level reaches the low level (LL)
probe, power to terminal 2 on the WLC board is
present but no switching occurs.
After the water level reaches the high level (HL)
probe, the inverse latching relay of the board is
energized and locked through the low level probe
(LL) and ILR-1 contacts. With ILR-2 contacts open,
this de-energizes the HL relay and the HL LED goes
out. With the HL-3 contacts open, the boiler fill
solenoid is de-energized, stopping the flow of water
into the boiler.
Page 30 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Solid State - Auxiliary Low Level Cut-Off
This control serves as a safety backup to the main
water level control (WLC) board to meet Cal-Code
and CSD-1 code requirements. The operation of the
auxiliary control is identical to the low level cut-off
(LLCO) function of the main WLC board but
performs a single function: 1) Provide auxiliary low
level cut-off protection to shut off the heat source in
case the water level drops below the low level cutoff (LLCO) probe. A single LLCO probe, identical to
the LLCO probe on the main WLC board, is
connected to the auxiliary control.
The auxiliary water level control (WLC) has input
voltage (120VAC) across terminals 11 and 12 which
powers the primary side of the transformer. On one
side of the transformer secondary, power is
provided to the control by a series path through
chassis ground (terminal 10). The other side of the
transformer secondary (12VAC) is attached to the
control that directs power to the other side of the
internal relay (LLCO). As water enters the boiler, it
becomes part of the auxiliary water level control’s
circuit. When the water level in the boiler reaches
the LLCO probe, the circuit is completed.
When the main power switch is turned ON, power is
supplied to the auxiliary WLC board but no
switching occurs. On CSD-1 models, the low water
level indicator light (amber) on the boiler control box
comes on.
When the water level reaches the low level cut-off
(LLCO) probe, the LLCO relay is energized (LLCO-2
close) and the LLCO LED lights up. The LLCO relay
will remain energized and its LED will stay lit until
the water level in the boiler drops below the LLCO
probe.
When the boiler stops filling, press the manual reset
button on the boiler control box. On CSD-1 models,
this energizes the low water relay, turns off the low
water light and energizes the heat source auxiliary
control. On Cal-Code models, this closes and locks
the manual reset switch contacts to energize the
heat source auxiliary control.
Page 31 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Electro Mechanical - Low level Cut-Off & Differential Control
The steamer is equipped with three water level sensing probes (high, low and low level cut-off), a differential
level control (1G1GO) and a low level cut-off control (1D1DO). The low-level cut-off is an additional control that
is identical to the differential level control but serves as the safety backup to shut off the heat source in case the
water level drops below the low level cut-off (LLCO) probe. The differential level control maintains the water level
between the low and high water level probes.
Each control is powered by input voltage (120VAC) on terminals 1 and 2 which also connect to the primary side
of the internal transformer. The transformer secondary (300VAC) will provide power to the internal contactor coil
through a series path going from one side of the secondary winding, through the contactor coil, through the water
level control probe, through the water in the boiler and to the boiler for ground. The other side of the transformer
secondary is attached to the probe that directs power to the other side of the internal contactor coil.
When the main power switch is turned ON, both water level controls are energized. The boiler fill solenoid is then
energized through the normally closed contacts (terminals 3 & 4) on the differential level control and water
begins filling the boiler.
When the water level reaches the low level cut-off (LLCO) probe, the internal contactor coil on the low water
level control is energized. With the contacts on terminals 7 & 8 now closed, the heat source is then energized.
The internal contactor coil will remain energized until the water level in the boiler drops below the LLCO probe.
When the water level reaches the low level (LL) probe, power to terminal 7 on the differential level control will be
present but no switching occurs.
After the water level reaches the high level (HL) probe, the differential control contactor coil is energized and the
normally closed contacts on terminals 3 & 4 open, which de-energizes the boiler fill solenoid and stops the flow of
water into the boiler. The internal contactor coil will have a locking path through contacts 7 & 8 to the low level
probe to keep the coil energized after the water level drops below the high level probe.
When the water level drops below the low level (LL) probe, the internal contactor coil is de-energized, returning
contacts 3 & 4 back to their normally closed state and energizing the boiler fill solenoid to refill the boiler. The
water level must then fill to the high level probe again, to energize the internal contactor coil. The differential
control will toggle ON and OFF during a cooking cycle as needed.
Page 32 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Electro Mechanical - Auxiliary Low Level Cut-Off
This control serves as a safety backup to the main low level cut-off (LLCO) control to meet Cal-Code
requirements. The operation of the auxiliary control is identical to the main low level cut-off control but performs
a single function: 1) Provide auxiliary low level cut-off protection to shut off the heat source in case the water
level drops below the low level cut-off (LLCO) probe. A single LLCO probe identical to the LLCO probe on the
main low level cut-off control is connected to the auxiliary control.
The auxiliary control is powered by input voltage (120VAC) on terminals 1 and 2 which also connect to the
primary side of the internal transformer. The transformer secondary winding (300 VAC) will provide power to the
internal contactor coil through a series path going from one side of the secondary winding, through the contactor
coil, through the water level control probe, through the water in the boiler and to the boiler for ground. The other
side of the transformer secondary is attached to the LLCO probe which directs power to the other side of the
internal contactor coil.
When the main power switch is turned ON, the auxiliary low level control is energized but no switching occurs.
When the water level reaches the low level cut-off (LLCO) probe, the internal contactor coil on the low level
control is energized, closing the contacts on terminals 7 & 8. The internal contactor coil will remain energized
until the water level in the boiler drops below the LLCO probe.
When the boiler stops filling, press the manual reset button on the boiler control box. This closes and locks the
manual reset switch contacts to energize the heat source auxiliary control.
Page 33 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
SEQUENCE OF OPERATION
GAS MODELS
This sequence of operation is written for steamers
with automatic ignition, solid state water level
controls and the CSD-1 (code) option. Refer to
schematic diagram number 3707.
INITIAL FILL AND PREHEAT
1.
Conditions.
D.
A.
Power switch OFF.
B.
Ignition module reset switch ON
C.
Doors shut (closes the N.O. door switch
contacts).
D.
Cooking timers OFF.
E.
Unit connected to correct voltage
(120VAC).
1)
2)
2.
NOTE: The high pressure indicator light will remain
on and the safety circuit de-energized until boiler
steam pressure is within operational limits (high limit
pressure switch closed) and the manual reset button
is pressed. The low water indicator light will remain
on and the safety circuit de-energized until the water
level in the boiler reaches the low level cut-off
probes (minimum level) for the water level control,
the auxiliary low level cut-off control and the manual
reset switch is pressed. The gas burners will not
light until these conditions are satisfied.
L1 to one side of the cooking
compartment pressure switch (N.O.),
then to the other compartment
controls; to one side of the cold water
condenser thermostat; to one side of
the power ON/OFF switch.
NEUTRAL to one side of the cooking
compartment controls; to one side of
the cold water condenser (CWC)
solenoid valve; to one side of the
power ON/OFF switch.
F.
Unit properly grounded. (Boiler and water
level control share a common ground)
G.
Water supply valve on.
H.
Gas supply valve on.
I.
Gas combination control valve on.
J.
Control (cycling) pressure switch closed.
K.
High limit pressure switch closed.
L.
Cold water condenser (CWC) thermostat
open.
M.
Blowdown solenoid valve (drain) open and
boiler empty.
Power switch turned ON. (located on boiler
control box)
A.
Power switch indicator light (red) comes
on.
B.
Hi pressure indicator light (amber) comes
on.
C.
Low water level indicator light (amber)
comes on.
Water level control (WLC) is powered.
1)
High level (HL) relay is energized,
HL-3 (N.O.) contacts close and HL
LED lights up.
2)
The inverse latching relay of the
board remains de-energized, leaving
the ILR-1 (N.O.) and ILR-2 (N.C.)
contacts in their shelf state.
E.
Auxiliary low water level cut-off control is
powered, LLCO-2 (N.O.) contacts remain
open.
F.
With the HL-3 and ILR-2 contacts closed,
the fill solenoid is energized and water
boiler begins filling.
G.
Blowdown solenoid valve is energized and
closes.
H.
Ignition module begins sparking to light
pilot after a 3 second delay.
1)
If pilot ignition is established (pilot lit)
then a micro amp flame sense
current is sent back to the ignition
control module through the ignition
cable. Sparking stops, pilot remains
lit and is ready to ignite burners.
2)
If pilot ignition is not established after
90 seconds, sparking stops and the
ignition control module locks out
power to the combination gas valve
(pilot valve and main valve remain
closed). The module remains locked
out until the reset switch on the
ignition control module box is
switched to off then on to re-start the
ignition trial cycle.
NOTE: If the modules re-set switch is in the off
position, no sparking will occur or if it’s turned off
while in ready or cook mode then pilot and burners
will go out and not re-ignite upon call for heat by the
cycling pressure switch.
3.
Page 34 of 80
Water level reaches LLCO (low water level cutoff) probe for the water level control and to the
auxiliary LLCO probe for the auxiliary low level
cut-off control.
VSX SERIES STEAMER - ELECTRICAL OPERATION
A.
B.
Power to terminal 9 on the water level
control.
C.
Auxiliary gas solenoid valve is energized
and opens to allow gas flow.
1)
D.
As long as the ignition control module is
sensing a pilot flame, the internal main
valve (MV) contacts close (N.O.) on the
ignition control module. The main gas
valve is energized and gas begins flowing.
E.
Burners light and boiler begins to heat up.
LLCO relay energizes, LLCO-2 (N.O.)
contacts close and LED lights.
Power to terminal LLCO on the auxiliary
low water level cut-off control.
1)
LLCO relay energizes, LLCO-2 (N.O.)
contacts close and LED lights.
NOTE: LLCO relays will remain energized and
LLCO LED’S will remain lit until the water level
drops below the LLCO probes or the power switch is
turned off.
4.
Power to terminal 2 on the water level
control is present but no switching occurs.
Water reaches HL (high level) probe.
A.
Power to terminal 6 on water level control.
1)
The inverse latching relay of the
board is energized, changing the
state of ILR-1 (N.O.) and ILR-2 (N.C.)
contacts. The inverse latching relay
will remain energized through the
alternate latching path of ILR-1
contacts until the water level recedes
below the low level probe.
2)
With ILR-2 contacts open, HL relay is
de-energized, HL-3 (N.O.) contacts
open and HL LED goes out.
3)
6.
Cooking compartment pressure switch closes
as boiler steam pressure reaches 3 PSI.
(Approximately 14 min.)
A.
Water reaches LL (low level) probe.
A.
5.
7.
NOTE: If a cooking timer is set immediately after
the ready light comes on, a loud clanking sound will
be heard (oil caning) and the ready lights will flash
for several seconds. This condition is caused by the
manifold pressure being on the fringe of the
pressure switch set point. When a cook timer is set,
the compartment steam solenoid valve opens
causing the manifold steam pressure to drop,
slightly below the pressure switch set point. At the
same time, steam pressure is still increasing in the
boiler. This opposing condition causes a pressure
bounce to occur but after the steam pressure passes
approximately 4 psi this condition subsides. Under
normal steam cycling pressures, this condition will
not be seen.
8.
Water fill solenoid is de-energized.
(boiler fill time 4-11 min.)
Manual re-set switch is pressed, energizing the
coils on the high limit and low water relays.
A.
B.
Contacts 1 & 9 on the high pressure relay
change state and lock from N.C. to N.O.
and turn off the high pressure indicator
light. Concurrently, Contacts 1 & 9 on the
low water relay change state and lock from
N.C. to N.O. and turn off the low water
indicator light.
Contacts 5 & 9 on the high pressure relay
change state and lock from N.O. to N.C.,
supplying power (NEUTRAL) to one side
of the auxiliary gas solenoid valve.
Concurrently, Contacts 5 & 9 on the low
water relay change state and lock from
N.O. to N.C., supplying power (L1) to the
other side of the auxiliary gas solenoid
valve.
Cooking compartment ready light (green)
comes on.
Boiler steam pressure reaches upper limit set
point of 10 PSI. (Approximately 15 min.)
A.
Cycling pressure switch opens, main gas
solenoid valve de-energizes, gas flow
shuts off and burners go out.
B.
As boiler heats up and builds pressure,
some by-pass water/steam is produced
which runs into the steam drain box. This
causes the cold water condenser (CWC)
solenoid to cycle, cooling the drain water.
This solenoid is powered by the CWC
thermostat.
NOTE: Steam should not be seen entering either
compartment until a cook time is set. This energizes
the steam solenoid valve of the cooking
compartment to allow steam flow.
9.
NOTE: For both relays to energize, the high
pressure switch must be closed and the water level
in the boiler must be above the low level cut-off
probes in order for LLCO-2 (N.O.) contacts to close.
Page 35 of 80
Boiler steam pressure drops below lower limit
set point of 8 PSI and the cycling pressure
switch closes.
VSX SERIES STEAMER - ELECTRICAL OPERATION
A.
Boiler steam pressure is maintained by the
cycling of the pressure switch between the
upper and lower set point limits. The
cycling pressure switch continues to
energize and de-energize the main gas
solenoid valve starting and stopping the
flow of gas, which in turn, cycles the
burners on and off. This sequence
continues until one of the following occurs:
1)
2)
Boiler pressurizes to 15 PSI, causing
the high limit pressure switch to open.
At that time, the auxiliary gas valve
de-energizes, shutting off the gas
flow to the burners and the high limit
failure light will come on. This light
will stay lit until the pressure drops
below the lower limit set point of 6
PSI and the manual re-set switch is
pressed.
Boiler water level drops below the
LLCO probes for the water level and
the auxiliary low level cut-off controls
which then de-energizes the LLCO
relays, changing the contact state of
LLCO-2 (N.O.) back to open. This deenergizes the main and auxiliary gas
solenoid valves. The gas solenoid
valves will remain off and the low
water level light will come on and stay
lit until the water level rises above the
LLCO probes and the manual re-set
switch is pressed.
NOTE: Burners will re-light after the boiler pressure
drops below the low pressure set point limit (8 psi)
and will stay on until the high pressure set point (10
psi) is reached. As long as steam pressure is within
limits, even while cooking, burners can go off. The
boiler is able to re-pressurize to the upper set point
limit even with both compartments in cook mode.
NOTE: The cold water condenser thermostat
remains closed and cold water condenser solenoid
stays energized while cooking. If main water is shut
off after boiler fill, then no cold water is present to
condense steam/hot water and steam vapors exit
the floor drain.
3.
4.
5.
COOK CYCLE
1.
2.
A Cook cycle should not be started, until the
initial fill and preheat is completed, in order for
the boiler steam pressure to be within
operational limits.
Time expires on timer.
A.
Timer contacts 1/3 open.
B.
Steam solenoid valve de-energized,
stopping the flow steam into compartment.
C.
Cooking light goes out.
D.
Timer contacts 4/1 close and energize
buzzer until manually turned off.
E.
Ready light (green) comes on.
F.
Timer motor de-energized.
Timer manually turned off.
A.
Contacts 1/4 open
B.
Alarm Buzzer de-energized and stops
buzzing.
Steamer reverts to preheat cycle until time is
dialed into timer and the door is shut, water
level drops below low level cut-off probe or the
power switch is turned off.
WATER REFILL (AFTER INITIAL FILL)
1.
Water level drops below low level probe (LL).
A.
Ready light (green) is lit.
B.
Product is inserted into steamer.
Power is removed from terminal 2 on the
water level control .
C.
Door is closed.
1)
D.
Timer is dialed on timer.
A.
Contacts 1/3 of cook timer close.
B.
The inverse latching relay is deenergized, returning ILR-1 (N.O.) and
ILR-2 (N.C.) contacts back to their
original state.
HL relay is energized.
A.
Ready light (green) goes out.
B.
Cooking light (red) comes on.
1)
Contacts HL-3 close.
C.
Timer motor is energized.
2)
HL LED comes on.
D.
Compartment steam solenoid valve
energized and steam begins to enter the
compartment.
3)
Fill solenoid is energized and water
flows into tank.
2.
Water reaches LL (low level) probe.
A.
3.
Page 36 of 80
Power to terminal 2 on the water level
control is present but no switching occurs.
Water reaches high level probe.
VSX SERIES STEAMER - ELECTRICAL OPERATION
A.
The inverse latching relay of the water
level control is energized, changing the
state of ILR-1 (N.O.) and ILR-2 (N.C.)
contacts.
B.
HL relay is de-energized.
2)
1)
HL-3 opens.
2)
Fill solenoid de-energized and water
stops flowing into tank.
3)
HL LED goes out.
L2 (NEUTRAL) to in-line fuse (10
amp.); to the other side of the primary
on the step down transformer (H2);
from the other side of the secondary
winding (X1) to the other side of the
cooking compartment controls; to the
other side of the cold water
condenser (CWC) solenoid valve; to
the other side of the power ON/OFF
switch.
E.
Unit properly grounded. (Boiler and water
level control share a common ground)
F.
Water supply valve on.
G.
Control (cycling) pressure switch closed.
BOILER BLOWDOWN/DRAIN
H.
High limit pressure switch closed.
1.
I.
Cold water condenser (CWC) thermostat
open.
J.
Blowdown solenoid valve (drain) open and
boiler empty.
4.
The water refill cycle will occur whenever the
water level is below the low level probe and will
not affect the operation of either the preheat or
cook cycle.
Main power switch turned OFF.
A.
Boiler blowdown sequence starts.
B.
The blowdown solenoid valve (N.O.) is deenergized and valve opens to drain the
boiler.
C.
2.
Power is removed from all components
except cold water condenser (CWC)
thermostat and solenoid valve. The CWC
thermostat cycles as necessary to lower
the discharge temperature of the water
and condense steam going into the drain.
Power switch turned ON. (located on boiler
control box)
A.
Power switch indicator light (red) comes
on.
B.
Water level control (WLC) is powered.
1)
High Level (HL) relay is energized,
HL-3 (N.O.) contacts close and HL
LED lights up.
2)
The inverse latching relay of the
remains de-energized, leaving the
ILR-1 (N.O.) and ILR-2 (N.C.)
contacts in their shelf state.
ELECTRIC MODELS
This sequence of operation is written for steamers
with solid state water level controls and the CalCode option. Refer to schematic diagram number
3699.
INITIAL FILL AND PREHEAT
1.
C.
Auxiliary low water level cut-off control is
powered, LLCO-2 (N.O.) contacts remain
open.
D.
With the HL-3 and ILR-2 contacts close,
the fill solenoid is energized and boiler
begins filling.
E.
Blowdown solenoid valve is energized and
closes.
Conditions.
A.
Power switch OFF.
B.
Doors shut. (closes the N.O. door switch
contacts)
C.
Cooking timers off.
D.
Unit connected to correct voltage supply.
1)
L1 (HOT) to in-line fuse (10 amp.); to
one side of the primary on the step
down transformer (H1); from one side
of the secondary winding (X1) to one
side of the cooking compartment
pressure switch (N.O.), then to the
other compartment controls; to one
side of the cold water condenser
(CWC) thermostat (N.O.); to one side
of the power ON/OFF switch.
3.
Water level reaches LLCO (low water level cutoff) probe for the water level control and to the
auxiliary LLCO probe for the auxiliary low level
cut-off control.
A.
Power to terminal 9 on the main water
level control.
1)
B.
Power to terminal LLCO on the auxiliary
low level cut-off control.
1)
Page 37 of 80
LLCO relay energizes, LLCO-2 (N.O.)
contacts close and LLCO LED lights.
LLCO relay energizes, LLCO-2 (N.O.)
contacts close and LLCO LED lights.
VSX SERIES STEAMER - ELECTRICAL OPERATION
NOTE: LLCO relays will remain energized and
LLCO LED’S will remain lit until the water level
drops below the LLCO probes or the power switch is
turned off.
4.
Power to terminal 6 on the water level
control.
The inverse latching relay of the is
energized, changing the state of ILR1 (N.O.) and ILR-2 (N.C.) contacts.
The inverse latching relay will remain
energized through the alternate
latching path of ILR-1 contacts until
the water level recedes below the low
level probe.
NOTE: Steam should not be seen entering either
compartment until a cook time is set. This energizes
the steam solenoid valve of the cooking
compartment to allow steam flow.
9.
Boiler steam pressure drops below lower limit
set point of 11 PSI and the cycling pressure
switch closes.
Manual re-set switch is pressed.
Boiler steam pressure is maintained by the
cycling of the pressure switch between the
upper and lower set point limits. The
cycling pressure switch continues to
energize and de-energize the heating
element contactor(s), which in turn, cycles
the heating elements on and off. This
sequence continues until one of the
following occurs:
A.
Manual reset switch contacts (N.O.) close
and lock.
1)
B.
Heater contactors are energized, suppling
power to the heating elements.
C.
Water in boiler heats up.
Boiler pressurizes to 15 PSI, causing
the High Limit pressure switch to
open. At that time, the auxiliary
heating element contactors are deenergized, shutting off power to the
heating elements. The pressure
switch will remain open until the
pressure drops below the lower limit
set point of 6 PSI and the manual reset switch is pressed.
2)
Boiler water level drops below the
LLCO probes for the water level and
the auxiliary low level cut-off controls
which de-energizes the LLCO relays
and changes the contact state of
LLCO-2 (N.O.) back to open. This deenergizes the main and auxiliary
heating element contactors, shutting
off power to the heating elements.
The heating elements will remain off
until the water level rises above the
LLCO probes and the manual re-set
switch is pressed.
2)
With ILR-2 contacts open, HL relay is
de-energized, HL-3 (N.O.) contacts
open and HL LED goes out.
3)
Water fill solenoid is de-energized.
(boiler fill time 4-11 min.)
A.
Cooking compartment pressure switch closes
as boiler steam pressure reaches 3 PSI.
(Approximately 14 min.)
A.
Cooking compartment ready light (green)
comes on.
NOTE: If a cooking timer is set immediately after
the ready light comes on, a loud clanking sound will
be heard (oil caning) and the ready lights will flash
for several seconds. This condition is caused by the
manifold pressure being on the fringe of the
pressure switch set point. When a cook timer is set,
the compartment steam solenoid valve opens
causing the manifold steam pressure to drop,
slightly below the pressure switch set point. At the
same time, steam pressure is still increasing in the
boiler. This opposing condition causes a pressure
bounce to occur but after the steam pressure passes
approximately 4 psi this condition subsides. Under
normal steam cycling pressures, this condition will
not be seen.
8.
As boiler heats up and builds steam
pressure, some by-pass water/steam is
produced which runs in to the steam drain
box. This causes the cold water condenser
(CWC) solenoid to cycle, cooling the drain
water. This solenoid is powered by the
CWC thermostat.
Power to terminal 2 on the water level
control is present but no switching occurs.
1)
7.
B.
Water reaches HL (high level) probe.
A.
6.
Cycling pressure switch opens, heater
contactors de-energize and power to
heating elements is removed.
Water reaches LL (low level) probe.
A.
5.
A.
COOK CYCLE
1.
Boiler steam pressure reaches upper limit set
point pressure of 13 PSI. (Approximately 15
min.)
Page 38 of 80
A Cook cycle should not be started, until the
initial fill and preheat is completed, in order for
the boiler steam pressure to be within
operational limits.
VSX SERIES STEAMER - ELECTRICAL OPERATION
2.
A.
Ready light (green) is lit.
B.
Product is inserted into steamer.
C.
Door is closed.
D.
Timer is dialed on timer.
1)
B.
1)
Contacts HL-3 close.
A.
Ready light (green) goes out.
2)
HL LED comes on.
B.
Cooking light (red) comes on.
3)
C.
Timer motor is energized.
Fill solenoid is energized and water
flows into tank.
D.
Compartment steam solenoid valve
energized and steam begins to enter the
compartment.
NOTE: The cold water condenser thermostat
remains closed and cold water condenser solenoid
stays energized while cooking. If main water is shut
off after boiler fill, then no cold water is present to
condense steam/hot water and steam vapors exit
the floor drain.
4.
5.
2.
Water reaches LL (low Level) probe.
A.
3.
4.
Time expires on timer.
Power to terminal 2 on the water level
control is present but no switching occurs.
Water reaches high level probe.
A.
The inverse latching relay of the is
energized, changing the state of ILR-1
(N.O.) and ILR-2 (N.C.) contacts.
B.
HL relay is de-energized.
1)
HL-3 opens.
2)
Fill solenoid de-energized and water
stops flowing into tank.
3)
HL LED goes out.
The water refill cycle will occur whenever the
water level is below the low level probe and will
not affect the operation of either the preheat or
cook cycle.
A.
Timer contacts 1/3 open.
BOILER BLOWDOWN/DRAIN
B.
Steam solenoid valve de-energized,
stopping the flow steam into compartment.
1.
C.
Cooking light goes out.
D.
Timer contacts 4/1 close and energize
buzzer until manually turned off.
E.
Ready light (green) comes on.
F.
Timer motor de-energized.
Timer manually turned off.
A.
Contacts 1/4 open
B.
Alarm Buzzer de-energized and stops
buzzing.
Steamer reverts to preheat cycle until time is
dialed into timer and the door is shut, water
level drops below low level cut-off probe or the
power switch is turned OFF.
WATER REFILL (AFTER INITIAL FILL)
1.
HL relay is energized.
Contacts 1/3 of cook timer close.
NOTE: Heating elements will come on after the
boiler pressure drops below the low pressure set
point (11 PSI) and will stay on until the high
pressure set point (13 PSI) is reached. As long as
steam pressure is within these limits, even while
cooking, heating elements can go off. The boiler is
able to re-pressurize to the upper set point, even
with both compartments in cook mode.
3.
The inverse latching relay is deenergized, returning ILR-1 (N.O.) and
ILR-2 (N.C.) contacts back to their
original state.
Water level drops below low level probe (LL).
A.
Power is removed from terminal 2 on the
water level control.
Page 39 of 80
Main power switch turned OFF.
A.
Boiler blowdown sequence starts.
B.
The blowdown solenoid valve (N.O.) is deenergized and valve opens to drain the
boiler.
C.
Power is removed from all components
except cold water condenser (CWC)
thermostat and solenoid valve. The CWC
thermostat cycles as necessary to lower
the discharge temperature of the water
and condense steam going into the drain.
VSX SERIES STEAMER - ELECTRICAL OPERATION
PAGE PURPOSELY LEFT BLANK
Page 40 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
SCHEMATICS, GAS STEAMERS, BOILER CONTROLS
VSX24G, 36G AND 42GT
Manual Ignition, Standard Controls
Page 41 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Electronic Ignition, Standard Controls
Page 42 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Manual Ignition, CSD-1 Code Controls
Page 43 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Electronic Ignition, CSD-1 Code Controls
Page 44 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Page 45 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
WIRING DIAGRAMS, GAS STEAMERS, BOILER CONTROLS
VSX24G, 36G AND 42GT
Manual Ignition, Standard Controls
Page 46 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Page 47 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Electronic Ignition, Standard Controls
Page 48 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Page 49 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Manual Ignition, CSD-1 Code Controls
Page 50 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Page 51 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Electronic Ignition, CSD-1 Code Controls
Page 52 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Page 53 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
SCHEMATICS, ELECTRIC STEAMERS, BOILER CONTROLS
VSX24E, 36E AND 42ET
Auto Blowdown, Standard Controls
Page 54 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown, Cal-Code Controls
Page 55 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown, Standard Controls
Page 56 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown, Cal-Code Controls
Page 57 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
WIRING DIAGRAMS, ELECTRIC STEAMERS, BOILER CONTROLS
VSX24E, 36E AND 42ET
Auto Blowdown, Standard Controls
Page 58 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Page 59 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown, Cal-Code Controls
Page 60 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Page 61 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown, Standard Controls
Page 62 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Page 63 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown, Step Down Transformer, Standard Controls
Page 64 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Page 65 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown, Step Down Transformer, Cal-Code Controls (2 contactors)
Page 66 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Page 67 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown, Step Down Transformer, Cal-Code Controls (4 contactors)
Page 68 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Page 69 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
WIRING DIAGRAMS, ELECTRIC HEATER CIRCUITS
VSX24E, 36E AND 42ET
Standard and Cal-Code/CSD-1 Controls (Newer Models)
Page 70 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Standard and Cal-Code Controls (Older Models)
Page 71 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
3 Phase, 4 Wire (Older Models)
Page 72 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
SCHEMATIC, DIRECT STEAMERS, CABINET BASE
VSX24D, 36D AND 42DT
See “SCHEMATIC ALL MODELS - COMPARTMENT CONTROLS”
WIRING DIAGRAM, DIRECT STEAMERS, CABINET BASE
VSX24D, 36D AND 42DT
See “WIRING DIAGRAM ALL MODELS - COMPARTMENT CONTROLS”
Page 73 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
WIRING DIAGRAMS, REGENERATED STEAMERS, BOILER CONTROLS
VSX36R AND 42RT (OLDER MODELS)
Manual Blowdown
Page 74 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
Auto Blowdown
Page 75 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
SCHEMATIC ALL MODELS - COMPARTMENT CONTROLS
Page 76 of 80
VSX SERIES STEAMER - ELECTRICAL OPERATION
WIRING DIAGRAM, ALL MODELS - COMPARTMENT CONTROLS
Page 77 of 80
VSX SERIES STEAMER - TROUBLESHOOTING
TROUBLESHOOTING
ALL MODELS
WARNING: CERTAIN PROCEDURES IN THIS SECTION REQUIRE ELECTRICAL TESTS OR
MEASUREMENTS WHILE POWER IS APPLIED TO THE MACHINE. EXERCISE EXTREME CAUTION AT ALL
TIMES. IF TEST POINTS ARE NOT EASILY ACCESSIBLE, DISCONNECT POWER, ATTACH TEST
EQUIPMENT AND REAPPLY POWER TO TEST.
SYMPTOM
POSSIBLE CAUSES
Compartment leaks water around door.
1.
2.
Steamer not level.
Drain line obstructed or not to an open gap drain.
Cold water condenser not operating
properly.
1.
2.
3.
4.
5.
Cold water condenser solenoid inoperative or plugged.
Lack of water supply.
Cold water condenser thermostat malfunction or needs
adjustment.
No power to cold water condenser solenoid.
Plugged spray nozzle.
Steam leaks around door.
1.
2.
3.
Worn gasket - See “DOOR” in “SERVICE PROCEDURES ”.
Damaged gasket.
Drain line obstructed or not to an open drain.
Steam generated inside compartment
when timer is off.
1.
2.
Steam supply solenoid not fully closing (clogged or dirty).
See “FILL AND COLD WATER SOLENOID VALVES” in
“SERVICE PROCEDURES”.
Timer contacts 1 & 3 closed.
Heat coming on without water in boiler
(Dry firing).
1.
2.
3.
Dirty water level probes (shorted to ground).
Retention of water in probe canister assembly.
Water level control malfunction.
Pressure relief valve opening or leaking.
1.
Cycling pressure switch set to high. See “PRESSURE
SWITCHES (GAS AND ELECTRIC MODELS)” in “SERVICE
PROCEDURES”.
Pressure relief valve malfunction.
2.
Base unit will not heat or build pressure.
1.
2.
Check incoming voltage.
Boiler not filled - check fill solenoid for power, clogging or
malfunction.
3. Water Level Control malfunction.
4. Water too “pure” for probes to properly conduct electricity.
5. Contactor malfunction (electric only).
6. Heating element inoperative (electric only).
7. Cycling pressure switch open or set too high. Unit is cycling
on high limit.
8. High limit thermostat open.
9. Problem with auto blowdown timer (older models).
10. Power switch malfunction.
11. Pressure reducing valve malfunction or needs cleaned
(direct or regenerated units only).
12. Low or no steam supply to unit (direct or regenerated units
only).
Page 78 of 80
VSX SERIES STEAMER - TROUBLESHOOTING
SYMPTOM
Steam output low or slow cooking.
POSSIBLE CAUSES
1.
7.
8.
Blocked steam injector ports. (Open door, press door switch
button and verify good steam flow into compartment)
Steam solenoid valve not fully opening or blocked.
Steam intake shut-off valve closed or out of adjustment. See
“INTAKE SHUT-OFF VALVE ADJUSTMENT (STEAM
FLOW)” in “SERVICE PROCEDURES”.
Cycling pressure switch malfunction or needs adjustment.
Steam header line (supply) blockage.
Heavy amount of condensate in the pressure controls steam
supply line.
Pressure relief valve leaking.
Steam supply lines leaking badly.
Unit leaks water.
1.
2.
3.
Loose water, steam or drain line connections (top or base).
Boiler hand hole gasket not sealing.
Leak at gauge glass.
Boiler water level too high.
1.
2.
3.
Fill solenoid does not shut off.
High level probe dirty (open circuit).
Water level control malfunction.
Boiler does not fill.
1.
2.
3.
Water supply not on.
Fill solenoid not opening or plugged.
Water level control malfunction.
Timer motor does not run.
1.
2.
3.
Door open or door switch inoperative.
Timer not getting power.
Timer motor inoperative.
Door not closing properly.
1.
Door latch assembly malfunction or out of adjustment. See
“DOOR” in “SERVICE PROCEDURES”
Striker adjustment. See “DOOR” in “SERVICE
PROCEDURES”
2.
3.
4.
5.
6.
2.
Door won’t open.
1.
Latch won’t release see “DOOR” in “SERVICE
PROCEDURES”.
Buzzer not operating.
1.
2.
Timer malfunction.
Buzzer malfunction.
Page 79 of 80
VSX SERIES STEAMER - TROUBLESHOOTING
GAS MODELS ONLY
SYMPTOM
Burner won’t light.
POSSIBLE CAUSES
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Burner won’t stay lit.
1.
2.
3.
Pilot not lit or goes out.
1.
2.
3.
4.
5.
6.
7.
8.
Spark Ignitor not sparking.
1.
2.
3.
4.
5.
6.
7.
Form 24627 (December 98)
Gas not on.
Ignition control module reset switch in the OFF position or
malfunctioning.
Ignition module not receiving power. Check ignition module
transformer for 24VAC output to module on automatic ignition
systems.
Unit not properly grounded and/or polarity of incoming power is
incorrect on automatic ignition systems.
Low incoming gas pressure. See “MANIFOLD PRESSURE
ADJUSTMENT” in “SERVICE PROCEDURES”.
Ignition module malfunction.
Gas combination control valve malfunction.
Boiler not filling. Check fill solenoid for power, clogging or
malfunction.
Water level control malfunction.
Water too ”pure” for probes to properly conduct electricity.
High limit thermostat open (if equipped).
High limit pressure switch open.
Cycling pressure switch open or set too high. Unit is cycling on
high limit. See “PRESSURE SWITCHES (GAS AND ELECTRIC
MODELS) in SERVICE PROCEDURES”.
Gas pressure low. See “MANIFOLD PRESSURE ADJUSTMENT”
in “SERVICE PROCEDURES”.
Ignition module malfunction.
Check gas orifice for obstruction.
Gas not on.
Low incoming gas pressure.
Check thermopile millivolts.
Pilot going out due to drafts, excess steam from drain or unit not
level. Improper venting can direct the pilot flame away from
thermopile or flame sensor.
Pilot not adjusted correctly. See “PILOT, THERMOCOUPLE OR
MAIN BURNERS” in “SERVICE PROCEDURES”.
Burners ignite too violently. Check gas pressure to the unit. See
“MANIFOLD PRESSURE ADJUSTMENT” in “SERVICE
PROCEDURES”.
If auto ignition and no sparking - ignition module malfunction.
Wrong pilot assembly used.
Incorrect spark gap setting. See “AUTOMATIC IGNITION
SYSTEMS” in “SERVICE PROCEDURES”.
Poor ground between pilot bracket and burner.
Loose, broken or damaged lead wires (including ground) from
ignition module to ignitor.
Ignitor boot on ignition cable loose, damaged or missing causing
excessive ignition voltage leakage.
Ceramic flame rod insulator on ignitor cracked or damaged from
extreme heat.
Ignition module not receiving power.
Ignition module malfunction.
Printed in U.S.A.