Bosch Aquastar GWH 1600 H N User manual


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Bosch Aquastar GWH 1600 H N User manual | Manualzz

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MODEL GWH 1600 H

INDOOR MODEL

Hydro-generated ignition

Suitable for heating potable water only

Not approved for space heating or preheated water applications

GWH 1600 H N - Natural Gas

GWH 1600 H L - Liquefied Petroleum (LP) Gas

Warning: If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or death.

Do not store or use gasoline or other flammable vapor and liquids in the vicinity of this or any other appliance.

Improper installation, adjustment, alteration, service or maintenance can cause injury or property damage. Refer to this manual. For assistance or additional information consult a qualified installer, service agency or the gas supplier.

In the Commonwealth of Massachusettes the installation must be performed by a licensed plumber or gas fitter.

Upon completion of the installation, these instructions should be handed to the user of the appliance for future reference.

What to do if you smell gas

• Open windows.

• Close gas valve.

• Do not try to light any appliance.

• Do not touch any electrical switch; do not use any phone in your building.

• Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions.

• If you cannot reach your gas supplier, call the fire department.

• Installation and service must be performed by a qualified installer, service agency or the gas supplier.

Index

Index

1

3.4

3.5

3.6

3.7

3

3.1

3.2

3.3

Warning

2

2.1

2.2

2.3

2.4

Appliance details

GWH 1600 H specifications (Technical data)

Unpacking the GWH 1600 H heater

General rules to follow for safe operation

Dimensions and installation clearances

Installation instructions

Introduction

Proper location for installing your heater

Heater placement and clearances

Mounting Heater

Combustion air requirements

Venting

Gas piping & connections

3.8

3.9

Measuring gas pressure

Water connections

3.10

Recirculation application

4

4.1

4.2

4.3

4.4

4.5

4.6

Operation instructions 14

For your safety read before operating your water heater 14

Lighting instructions

To turn off appliance

15

15

Setting the water temperature

Power adjustment

Purge the appliance

16

16

16

8

11

7

8

6

6

6

6

13

13

14

2

4

4

3

3

5

5

5.1

5.2

5.3

5.4

5.5

5.6

Maintenance and service

Maintenance intervals

Water valve

Pilot

Main burners

Vent assembly

Mineral scale build-up

6

6.1

6.2

6.3

6.4

6.5

6.6

6.7

6.8

6.9

Troubleshooting

Introduction

19

19

No spark at pilot with water flow

Spark appears when hot water is turned on, but pilot and

19 burners will not ignite

Pilot light, but burners will not come on.

Main burners go out during hot water use

Hot water temperature fluctuates at tap

Water is too hot

Water is not hot enough

Burners ignite without water flow

6.10

Low hot water pressure

6.11

Noise when heater is running

6.12

Burners do not burn cleanly, yellow flames when operating

19

20

20

21

23

21

22

22

22

22

17

17

17

17

18

18

18

7 Protecting the environment

8

8.1

8.2

8.3

Interior components and diagram parts list

Interior components

Components diagram

Parts list

23

24

24

25

26

9 Twelve Year Limited Warranty 27

Fig. 1

1 Warning

Warning: The heater must be isolated from the gas supply piping system during any pressure testing of that system at test pressures equal to or more than 0.5 psig.

Caution: Any changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.

2

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Appliance details

2 Appliance details

2.1

GWH 1600 H specifications

(Technical data)

Approved in US/Canada

Capacity

GWH 1600 H: 4.36 GPM

Maximum output

GWH 1600 H: 91,525 Btu/hr

Maximum input

GWH 1600 H: 117,000 Btu/hr

Efficiency in %

Recovery efficiency 80%

Min. Output

GWH 1600 H: 23,906 Btu/hr

Gas Requirement

Gas connection (inches) - ¾” NPT

Inlet gas pressure under maximum operation*

• Propane: 10.5” - 14” water column

• Natural Gas: 5.7” - 14” water column.

* To measure Gas Pressure, see Measuring Gas

Pressure, chapter 3.8.

Venting

• Natural Draft

• Vent diameter (inches) - 5”

• Minimum height (feet) - 6’ with no elbows

• Vertical termination

• Sidewall termination only with AQ4 power vent kit.

Water

• Hot water connection (inches) - ½” NPT

• Cold water connection (inches) - ½” NPT

• Water valve material: Polymer (PPS) (Polypropylene

Sulfid)

• Minimum water flow: 0.6 gallon/minute (2.2 l/m)

• Minimum recommended water pressure: 30 PSI

(2.07 bar)

• Connections:

– Bottom of heater

Dimensions

• Depth (in): 8.66” (220 mm)

• Width (in): 16.73” (425 mm)

• Height (in): 25.79” (655 mm)

• Weight: 35 pounds (16 kg).

Gas types

Natural Gas.

LP Gas

Safety devices

• Flame failure device (ionization flame rod sensor)

• Pressure relief valve (supplied with heater)

• Over heat prevention (temperature limiter).

Water resistant

IP X4.

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3

4

Appliance details

2.2

Unpacking the GWH 1600 H heater

This heater is packed securely.

Before installing the unit, be certain you have the correct heater for your type of Gas - Propane or

Natural Gas. Identification labels are found on the shipping box, and on the rating plate which is located on the right side panel of the cover.

Fig. 2 Rating plate

A

B

Serial number

Type of gas

The box includes:

• Pressure relief valve

• Mounting screws

• Product registration card

• Installation manual

• Incandescent particle tray.

Do not lose this manual, there is a charge for a

replacement.

Please complete and return the enclosed product registration card.

The GWH 1600 H is not approved or designed for:

• Manufactured (mobile) homes, RV's or boats

• Heating or other recirculating/pumping applications*

• Solar/preheat backup or high temperature booster use

• Installation in bathroom, bedroom or other occupied rooms normally kept closed.

* This includes domestic hot water circulator pump loop systems that may be installed in home hot water system prior to installing this unit. An approved recirculation design can be found in chapter 3.10.

2.3

General rules to follow for safe operation

1. You should follow these instructions when you install your heater. In the United States: The installation must conform with local codes or, in the absence of local codes, the National Fuel Gas Code ANSI Z223.1/

NFPA 54.

In Canada: The Installation should conform with CGA

B149.(1,2) INSTALLATION CODES and /or local installation codes.

2. Carefully plan where you install the heater. Proper clearances must be followed.

3. The appliance must be isolated from the gas supply piping system by closing its individual manual gas shutoff valve (not supplied with heater) during any pressure testing at pressures in excess of ½ Psig (3.5

kPa).

The appliance and its gas connection must be leak tested before placing the appliance in operation.

4. Keep water heater area clear and free from combustibles and flammable liquids. Do not locate the heater over any material which might burn.

5. Correct gas pressure is critical for the optimum operation of this heater. Gas piping must be sized to provide the required pressure at the maximum output of the heater, while all the other gas appliances are in operation. Check with your local gas supplier, and see chapter 3.7 and 3.8 to verify proper gas line sizing.

6. Should overheating occur or the gas supply fail to shut off, turn off the gas supply at the manual gas shut off valve, on the gas line. Note: manual gas shutoff valve is not supplied with the heater.

7. Do not use this appliance if any part has been underwater. Immediately call a qualified service technician to inspect the appliance and to replace any part of the control system and any gas control which has been underwater.

i BOSCH is constantly improving its products, therefore specifications are subject to change without prior notice.

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2.4

Dimensions and installation clearances

Appliance details

Fig. 3 Dimensions in Inches and (mm)

36

37

38

39

40

49

51

110

20

23

26

34

4

5

10

11

Heat exchanger

Burner

Temperature control

Water valve

Gas connection

Igniter unit

Output control

LED indicator for burner status

Front cover

Hole for fixing to wall

Exhaust pipe to wall

Draught diverter with flue gas monitor

Gas valve

Observation window

On/Off switch

LED failure indicator

TOP (A)

FRONT (B)

BACK

SIDES

BOTTOM (C)

Fig. 4 Minimum clearances

Model GWH 1600 H

12 inches (306 mm)

4 inches (100 mm)

0 inches

4 inches (100 mm)

12 inches (306 mm)

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Dimensions inches (mm)

A

GWH 1600 H

16.73” (425)

D

E

B

C

F

G

25.75” (655)

13.15” (334)

5.11” (130)

21.25” (540)

2.55” (65)

1.18” (30)

H 3/4”

Table 1 Dimensions in inches (mm)

5

Installation instructions

3 Installation instructions

3.1

Introduction

Please follow these instructions. Failure to follow instructions may result in:

B Damage or injury.

B Improper operation.

B Loss of warranty.

If you are unable to perform the tasks required to install this heater properly, please contact a locally licensed plumber or gas technician.

Please contact Bosch Water Heating with any questions.

3.2

Proper location for installing your heater

Carefully select the location of the water heater. For your safety and for proper heater operation, you must provide combustion air to the heater and a proper exhaust vent system.

Follow the guidelines below:

B 1. Locate the heater where venting, gas and plumbing connections are feasible and convenient.

B 2. The hot water lines should be kept short to save energy. Centrally locating the water heater is best. It is always best to have hot water lines insulated.

Warning: The water in this water heater is cold and always remains cold except for the times that hot water is being used DO NOT INSTALL IN AN

AREA WHERE IT COULD FREEZE.

Drain the heater entirely if freezing temperatures are anticipated in area where heater is installed. See chapter

4.6 for draining instructions.

To prevent any freeze damage, introduce short bursts of compressed air (20-40psi) through these connections to remove the residual water in the horizontal pipes and water valve.

Warning: Flammable materials, gasoline, pressurized containers, or any other items or articles that are potential fire hazards must NOT be placed on or adjacent to the heater. The appliance area must be kept free of all combustible materials, gasoline and other flammable vapors and liquids.

Warning: The heater must be isolated from the gas supply piping system during any pressure testing of that system at test pressures equal to or more than 0.5 psig.

Warning: Place the heater in a location where water leaks will do NO DAMAGE to adjacent areas.

3.3

Heater placement and clearances

The GWH 1600 H is design certified for installation on a combustible wall (see 3.4 Mounting installation) provided the floor covering below the heater is noncombustible. For installations in an alcove or closet, maintain the minimum clearances to combustible and non-combustible materials listed below. See also Fig. 4.

A. Top 12 inches (306 mm)

B. Front 4 inches (100 mm)

C. Back 0 inches

D. Sides 4 inches (100 mm)

E. Bottom 12 inches (306 mm)

6

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3.4

Mounting Heater

Warning: before starting installation:

B check that there are no loose parts inside the appliance.

B ensure that gas pipe, gas valve, and burner have no damage and are properly fitted.

B Read chapter 2.2 to verify proper gas type and to check all parts are included in box.

i Front cover should be removed in order to inspect components visually (see instructions below).

Remove cover and inspect.

B Remove the temperature control.

B Remove the outer case by pulling it forwards and then lifting upwards.

B Ensure that the flue terminal is clear.

B After inspection, replace front cover.

Install incandescent particle tray.

B Install incandenscent particle tray using screws provided as shown in Fig. 5.

Fig. 6 Remove front cover

Installation instructions

Fig. 7 Support board

Screws

Incandescent particle tray

Fig. 5 Incandescent particle tray illustration

Mounting heater.

The GWH 1600 H is design certified for mounting on a wall.

Warning:

B Do not install this appliance on a carpeted wall.

The heater must be mounted on a wall using appropriate anchoring materials. If wall is a stud wall sheathed with plasterboard, it is recommended that support board(s), either 1x4’s or 1/2" (minimum) plywood first be attached across a pair of studs and then the heater should be attached to the support boards. See Fig. 7.

B Secure the two included L shaped hooks to wall studs or support board 13 ¼” apart (See Fig. 7).

B Hang heater on two L shaped hooks (See Fig. 8).

Fig. 8 Secure heater to wall

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7

Installation instructions

3.5

Combustion air requirements

The AquaStar water heater holds cold water in its copper heat exchanger and water valve when not in use.

Because of this, any cold air that comes down through the unit's vent pipe is capable of freezing these components. This Installation Manual specifies the minimum vertical vent pipe and the amount of combustion air required for this unit. When all requirements are followed, the unit will operate properly and safely. However, there may still be a risk of freezing due to negative draft if all the combustion appliances in the area are not being supplied with a sufficient amount of make-up air. A wood stove or furnace can rob the makeup air in the AquaStar's vent pipe, leaving the cold infiltrating air capable of freezing the cold water in the

AquaStar heat exchanger. Supplying more combustion air for all combustion appliances is the solution. Follow the instructions on venting and checking adequacy of make up air. A HVAC specialist should be used to design solutions for providing more make-up air if necessary. Observe the following instructions concerning combustion air.

Appliances located in unconfined spaces:

a) An unconfined space is one whose volume is greater than 50 cubic feet per 1000 Btu per hour of the combined rating of all appliances installed in the space.

That would be 5850 cubic feet for the AquaStar GWH

1600 H alone.

b) Installations in structures that have been tightly constructed (air infiltration rate of 0.40 ACH or less) must be provided for combustion air per the National

Fuel Gas Code. Consult a HVAC specialist if your air infiltration rate is questionable.

Appliances located in confined spaces:

The confined space must be provided with two permanent openings, one commencing within 12 inches of the top and one commencing within 12 inches of the bottom of the enclosure. Each opening must have a minimum free area of one square inch per:

• 1000 Btu/hr if all air is taken from inside the building.

• 2000 Btu/hr if all air is taken from the outside by horizontal ducts.

• 4000 Btu/hr if all air is taken from the outside by direct openings or vertical ducts.

Or the confined space must be provided with one permanent opening or duct that is within 12 inches of the ceiling of the enclosure. This opening must have a minimum free area of one square inch per:

• 3000 Btu/hr if all air is taken from the outside by a direct opening or vertical duct.

Louvers, grills and screens have a blocking effect. If the effective free area is not known, increase the sizes of your openings by 400% if your louvers are wood and by

135% if your louvers are metal. Refer to the National

8

Fuel Gas Code for complete information. In buildings of tight construction all air should be taken from outside.

3.6

Venting

Danger: Do not reduce the vent pipe size. Do not put an elbow directly on top of heater. Failure to follow venting requirements may result in dangerous exhaust gases to enter living space.

B Minimum vent pipe diameter: 5 inches

B Minimum vertical vent height: 6 feet, with no elbows

B Establish 12 inch rise before any elbow

The heater must be vented to the outside following all local ordinances and specifications for installing a gas appliance vent or chimney. The heater must be located as close as practicable to a vertically rising chimney or vent that has a listed vent cap at its termination point.

The venting system must be designed and constructed so as to develop a positive flow adequate to remove flue gasses to the outdoors. Consult the National Fuel Gas

Code if the vent will have elbows or share venting with another natural draft appliance.

Warning: Do not combination vent with a mechanically vented appliance.

3.6.1

Horizontal venting

Warning: Horizontally venting to a vertically constructed vent stack along an outside wall of a building is not permissible.

Warning: Horizontally venting to a sidewall vent terminator (without power vent) is not permissible.

A power vent, with a proof-of-draft safety interlock device, is required and is available for sidewall venting.

Contact your dealer. In the Commonwealth of Massachusetts power vented applications must utilize proofof-draft safety interlock device.

3.6.2

Vertical venting

B A 5 inch diameter gas vent constructed of double wall Type B gas vent is recommended. A 6 inch vent is required in elevations greater than 2000 feet, see

Fig. 4. Under no circumstances should the vent pipe be reduced in size.

B An approved gas vent connector must be attached to the top of the water heater and rise vertically at least

12" before entering into an approved gas vent connector elbow.

B The minimum vertical gas vent height allowed is 6 feet; horizontal vent connectors and elbows are not to be considered in the total gas vent height.

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Installation instructions

B All gas vent sections must be secured to each other with sheet metal screws and be properly supported.

Horizontal runs:

Any gas vent section that is greater than 45 degrees from the vertical is considered horizontal. Horizontal sections must slope upwards at least ¼ inch for every foot of its horizontal length and be properly supported.

Keep the horizontal section short and avoid too many elbows. The maximum horizontal run allowed is half of the total vertical vent height; horizontal vent connectors and elbows are not to be considered in the total gas vent height.

Vent termination:

The gas vent constructed of double wall Type B gas vent must terminate above the roof surface with a listed vent cap at a height that's in accordance with Fig. 11 and table 2, provided they are at least 8 feet (2.4 m) from a vertical wall or similar obstruction. All other gas vents that are not able to terminate within the minimum specified height allowed must terminate not less than 2 feet (0.6 m) above the highest point where it's passed through the roof and at least 2 feet (0.6 m) higher than any vertical wall or similar obstruction within 10 feet (3.1

m).

LISTED VENT CAP

5” X 6” ADAPTOR

USED ON HIGH

ALTITUDE

Fig. 10 Vent Adaptor for High Altitude Installations

MINIMUM 6

FEET (1.8M)

LISTED GAS VENT

ESTABLISH A ONE

FOOT RISE BEFORE

ANY ELBOWS

Fig. 9 Flat roof

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9

Installation instructions

Masonry chimney

Masonry chimneys shall be built and installed in accordance with NFPS 211 or local codes. A minimum

5" diameter gas vent pipe (metal double wall Type B), or an approved clay flue liner or a listed chimney lining system must be used when venting into a naturally drafting, internal masonry chimney. 6 inch is required in elevations greater than 2000 feet, see Fig. 10. Local codes may require the use of both gas vent and an approved lining system when venting into a masonry chimney. The Commonwealth of Massachusetts requires the use of a listed liner. Lining systems include approved clay flue lining, a listed chimney lining system or other approved material that will resist corrosion, erosion, softening, or cracking from exhaust flue gases at temperatures up to 1800 degrees F. The lining system must be listed for use with naturally drafting, draft hood equipped gas appliances. Follow local codes and refer to NFGC 54 and NFPA 58.

Existing interior masonry chimney

The metal gas vent pipe should be permanently mounted inside the masonry chimney. Double wall Type

B gas vent is recommended. The masonry chimney may have to be tile or metal lined before the insertion of the gas vent pipe; check local codes for clarification. The lining material must be listed for use only with naturally drafting, draft hood equipped gas appliances. Follow manufactures instructions for installation of listed lining material. You may not vent any other fuel burning appliances into any free space remaining in the chimney. The minimum vertical gas vent length within the masonry chimney should be no less than 5 ft (1.5

m); the vent terminator should extend at least 3 feet (0.9

m) above where the chimney meets the roofline and at least 2 feet (0.6 m) higher than any vertical wall or similar obstruction within 10 feet (3.1 m). The top of the gas vent should have an approved vent terminator. See

Fig. 12.

LOWEST DISCHARGE

OPENING

H (minimum) height from roof to lowest discharge opening

LISTED GAS VENT

ESTABLISH A ONE

FOOT RISE BEFORE

ANY ELBOWS

LISTED VENT CAP

12

ROOF

PITCH IS

X/12

X

MINIMUM 6

FEET (1.8M)

Fig. 11 Pitch roof

GAS VENT TERMINATIONS FOR LISTED VENT CAPS

Roof pitch H (minimum) feet meters

Flat to 6/12

6/12 to 7/12

1.0

1.25

0.30

0.38

Over 7/12 to 8/12

Over 8/12 to 9/12

Over 9/12 to 10/12

Over 10/12 to 11/12

1.5

2.0

2.5

3.25

0.46

0.61

0.76

0.99

Over 11/12 to 12/12

Over 12/12 to 14/12

Over 14/12 to 16/12

Over 16/12 to 18/12

Over 18/12 to 20/12

Over 20/12 to 21/12

Table 2

4.0

5.0

6.0

7.0

7.5

8.0

1.22

1.52

1.83

2.13

2.27

2.44

GAS

VENT

LISTED

VENT CAP

VENT

CONNECTOR

Establish a one foot rise before any elbows

Fig. 12 Masonry chimney

10

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Installation instructions

3.7

Gas piping & connections

Before connecting the gas supply, check the rating plate on the right side of the heater to be sure that the heater is rated for the same gas to which it will be connected.

In the United States: The installation must conform with local codes or, in the absence of local codes, the

National Fuel Gas Code ANSI Z223.1/NFPA 54.

In Canada: The Installation should conform to CGA

B149 INSTALLATION CODES and/or local installation codes.

Mount regulator to gas inlet pipe as shown in Fig. 13.

The arrow on the back of the regulator indicates the direction of gas flow and should point toward the appliance.

Fig. 13 Installation of Gas Pressure Regulator

Note: The GWH 1600 H comes with a gas pressure regulator. Failure to install or altering the gas pressure regulator will be a violation of CSA certification of the unit. The regulator supplied with the heater is preset for the gas shown on the rating plate to the correct pressure. It is an appliance level regulator designed for

(low inlet) pressure (less than 1/2 Psig or 14" W.C.).

Warning: DO NOT connect to an unregulated or high pressure propane line or to a high pressure commercial natural gas line.

Warning: The heater must be isolated from the gas supply piping system during any pressure testing of that system at test pressures equal to or more than 0.5 psig. If overpressure has occurred, such as through improper testing of the gas lines or malfunction of the supply system, the gas valve must be checked for safe operation.

GAS CONNECTIONS

B Install a manual gas shut off valve, on the gas supply line.

B Install a union when connecting gas supply.

B Attach the appliance regulator to the inlet gas pipe.

B The minimum diameter required for any appliance connector used is ¾” NPT.

B National Fuel Gas Code requires that a sediment trap (drip leg) be installed on gas appliances not so equipped. The drip leg must be accessible and not subject to freezing conditions. Install in accordance with the recommendations of the serving gas supplier.

When connections are made, check for gas leaks at all joints. Apply some gas leak detection solution to all gas fittings. Bubbles are a sign of a leak. A combustible gas detector may also be used to detect for leaks.

Danger: If you have a leak, shut off the gas. Tighten appropriate fittings to stop leak. Turn the gas on and check again with a gas leak detection solution.

Never test for gas leaks using a match or flame.

HIGH ALTITUDE INSTALLATION

The pressure regulator provided with the heater is adjusted to deliver the proper gas pressure (as indicated on the rating plate and in the manual for altitude up to 2000 feet (660 meters) above sea level.

On appliances being installed above 2000 ft (660 meters) elevation, the inlet gas pressure should be set at installation to the value shown below.

Note: The gas pressures specified below refer to pressures taken at the pressure tap on the gas inlet pipe just above the regulator. See chapter 3.8 for measuring gas pressure.

MAXIMUM INLET GAS FLOW PRESSURE SETTING

Altitude

Nat. Gas inches W.C.

5.7”

Liquid Propane inches W.C.

10.5” 0’ - 2 000 ft

2 000 ft - 4 500 ft 4.6” 8.4”

Table 3 Above 4.500 ft consult your local gas provider

GAS LINE SIZING

The gas supply piping should be sized according to the applicable code for a maximum draw of 117,000 BTUH.

Measure the length of gas supply line and use the tables in Fig. 14 or the gas line manufacturer’s sizing tables to determine the pipe diameter necessary to accommodate the BTU demand of the unit. If there are more gas appliances drawing on the same line, size the gas line according to the total maximum amount of BTU draw for all appliances.

Note: Under sizing the gas line may result in diminished output and improper operation. See chapter 3.8 for the procedure to confirm gas pressure.

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11

Installation instructions

FOR NATURAL GAS

Maximum Capacity of pipe in Cubic Feet of Gas per Hour for Gas Pressure of 0.5 Psig or less and a Pressure drop of 0.3 in Water Column (0.75mbar).(Based on a 0.60 Specific Gravity Gas) Btu numbers given in thousands.

Copper tubing is prohibited for use with Natural Gas in the Commonwealth of Massachusetts and not recommended elsewhere.

Follow boxed numbers for piping just one GWH 1600 H (example: ¾” B.I. Natural Gas pipe for 20 ft (6.1m). will handle 190,000 btu’s (55.7 kWh). For multiple appliances combine the total btu input load and then refer to applicable chart below.

Nominal

Iron

Pipe

Size

Internal

Diameter inches inches

Length of Black Iron Pipe, Feet

10 20 30 40 50 60 70 80 90 100 125 150 175 200

3/4

1

1 1/4

0.824

278 190 152 130 115 105 96 90 84 79 72 64 59 55

1.049

520 350 285 245 215 195 180 170 160 150 130 120 110 100

1.380

1050 730 590 500 440 400 370 350 320 305 275 250 225 210

Length of Flexible Corrugated Stainless Steel Tubing (CSST), Feet

Tube size, inches EHD*

10 20 30 40 50 60

1/2 18 EHD 82 58 47 41 37 34

3/4 23 EHD 161 116 96 83

1 30 EHD 330 231 188 162

1 1/4 37 EHD 639 456 374 325

75 68

144 131

292 267

* EHD = Equivalent Hydraulic Diameter. The greater the value of EHD, the greater the gas capacity of the tubing .

FOR LP GAS

Maximum Capacity of Pipe in Thousands of BTU per Hour of Undiluted Petroleum Gases (at 11 inches Water Column Inlet

Pressure) (Based on a Pressure Drop of 0.5 Inch Water Column).

* EHD = Equivalent Hydraulic Diameter. The greater the value of EHD, the greater the gas capacity of the tubing.

N o m inal

Iro n pipe s ize inche s

1

1/2

3/4

Black Iron Pipe

Lenght of pipe, Feet

10 20 30 40 50 60 80 100 125 150 200

291 200 160 137 122 110 94 84 74 67 58

608 418 336 287 255 231 197 175 155 140 120

1145 787 632 541 480 434 372 330 292 265 227

Tube

Length of Flexible Corrugated Stainless Steel Tubing (CSST), Feet size inches EHD*

10 20 30 40 50 60

1/2

3/4

1

18 EHD 129 91

23 EHD 254 183

30 EHD 521 365

74

151

297

1 1/4 37 EHD 971 661 528

64

131

256

449

58 53

118 107

227 207

397 359

Maximum Capacity of Semi-Rigid copper Tubing in

Thousands of BTU per Hour of Undiluted Liquefied

Petroleum Gases (at 11 inches Water Column Inlet

Pressure).

(Based on a Pressure Drop of 0.5 Inch Water Column)

* Source National Fuel Gas Code NFPA 54, ANSI Z223.1

- No Additional Allowance is necessary for an ordinary number of fittings

Fig. 14

Outside diameter

Inch

Copper (LP gas only)

Length of Tubing, Feet

10 20 30 40

3/8 39 26 21 19

1/2 92 62 50 41

5/8 199 131 107 90

50

_

60

_

70

_

80

_

90 100

_ _

37 35 31 29 27 26

79 72 67 62 59 55

3/4 329 216 181 145 131 121 112 104 95 90

12

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Installation instructions

3.8

Measuring gas pressure

Connecting manometer

B Shut off gas.

B Remove front cover and locate inlet gas pressure measuring point on the right side, see Fig. 15.

B Loosen screw from test point on the right side and connect manometer tube on test point.

Fig. 15 Gas pressure measuring point

A Inlet tap

Static pressure test

B Turn gas supply back on.

B Record static gas pressure reading on back page of manual.

Operating pressure test

B Turn on all hot water taps served by the water heater.

B Set flow control knob fully clockwise.

B Operate all other gas appliances on same gas piping system at maximum output.

B Record operating gas pressure reading on back page of manual.

Gas pressures lower than 5.7" W.C. for Natural Gas or

10.5" W.C. for LP Gas will result in insufficient degree rise to the hot water being used, and must be corrected.

See Gas Line Sizing under chapter 3.7.

3.9

Water connections

When facing the heater, the ½” cold water inlet is on the bottom right and the hot water outlet is on the bottom left.

B Install unions or the Webstone service valves when connecting plumbing to the water heater. This will facilitate any necessary cleaning and servicing.

Although water piping throughout your structure may be other than copper, we recommend that copper piping or suitably rated stainless steel flex line piping be used for at least three feet before and after the heater (follow local codes if more stringent). Never sweat any rigid piping directly to or beneath the water connections or damage can occur to the internal water valve from heating of the pipe. Plastics or other PEX type plumbing line materials are not recommended for connecting directly to the water heater. Keep water inlet and outlet pipes to no less than ½" (12.7mm) diameter to allow the full flow capacity.

It is recommended that all water piping below the heater be properly insulated to avoid heat loss. The freeze protection provided with the heater will not prevent any freeze damage to the exterior water piping.

If the cold and hot connections to the heater are reversed, the heater will not function. Be certain there are no loose particles or dirt in the piping. Blow out or flush the lines before connecting to the water heater.

Full port valves should be installed on both the cold water supply and hot water outlet lines to facilitate servicing the heater (see Fig. 16). For installation on a private well system with the use of a pressure tank, the lowest pressure range setting recommended is 30-50 psi (2.07 and 3.45bar).

Connecting the pressure relief valve (PRV)

The pressure relief valve supplied with the heater must be installed at the time of installation. No valve is to be placed between the PRV and the heater. No reducing coupling or other restriction may be installed in the discharge line. The discharge line must be a minimum of

4” above a drain and installed such that it allows complete drainage of both the PRV and the line.

The location of the PRV must be readily accessible for servicing or replacement, and be mounted as close to the water heater as possible. See Fig. 16. To install the

PRV, a suitable fitting connected to an extension on a

“T” fitting can be sweated to the hot water line.

Support all piping.

Fig. 16 Plumbing Connections and Pressure Relief

Valve

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13

Operation instructions

3.10 Recirculation application

Since recirculation through the heater is not permissible, the following drawing is provided to outline a proper recirculation application using the Aquastar water heater with an Ariston minitank. This schematic is for illustration only and must not be used for actual installation without appropriate engineering and technical advice from a professional properly licensed in locality where the installation is made.

Fig. 17 Recirculation application

The use of a small electric mini-tank (4-6 gallon size) should be used for this application and designed so the pump will circulate the water through the mini-tank and the building's hot water return loop only. A timed or thermostatically controlled operation of the pump is commonly done. The GWH 1600 H should be plumbed in line before the mini-tank water heater. Contact Bosch

Water Heating if further instruction is needed.

4 Operation instructions

4.1

For your safety read before operating your water heater

Warning: If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal injury or loss of life.

B A. This appliance is equipped with electronic ignition for lighting the pilot and main burners. When turning the heater on, follow these instructions exactly.

B. Before operating the unit, set the On/Off switch to the On position. The On/Off switch is located behind the flip-down coverplate on the front panel strip. Smell all around the appliance area for gas. Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor.

WHAT TO DO IF YOU SMELL GAS

B Close gas valve. Open windows.

B Do not try to light any appliance.

B Do not touch any electric switch; do not use any phone in your building.

B Immediately call your gas supplier from a neighbors phone. Follow the gas supplier’s instructions.

B If you cannot reach your gas supplier, call the fire department.

C. Use only your hand to push in the on/off control button. Never use tools. Follow these instructions exactly. If control button is jammed, close the gas supply and call a qualified service technician.

Attempted forceful repair may result in a fire or explosion.

D. Do not use this appliance if any part has been under water. Immediately call a qualified service technician to inspect the appliance and to replace any part of the control system and any gas control which has been under water.

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Operation instructions

4.2

Lighting instructions

B 1. STOP! Read the previous safety information.

B 2. The gas valve must be shut off by putting the ON/

OFF switch to position OFF . Wait five (5) minutes to clear out any gas. If you smell gas, STOP!

Follow “B” in chapter 4.1. If you do not smell gas, go to the next step.

B 3. This water heater is equipped with a safety pilot burner and an automatic ignition control system.

B 4. Set the ON/OFF switch (open cover plate on left panel strip) to the position ON . In this position, the water heater is ready to use.

4.3

To turn off appliance

B Set the ON/OFF switch to the position OFF .

Fig. 19

B Shut installer supplied manual gas shutoff valve on the supply line to the heater.

Fig. 18

B 5. Open hot water tap to a flow rate above the minimum activation rates listed in table 4. The automatic ignition system first ignites the safety pilot burner which then ignites the main burner in about 4 seconds.

B 6. The green LED indicator is on when the main burner is on.

B 7. The pilot flame will extinguish 10-30 seconds after the burners come on. The burners will remain on until the hot water tap is turned off.

Note: The GWH 1600 H operates in two modes. See

SETTING THE WATER TEMPERATURE.

i

Note: On first time initial installation, existence of air in the gas supply line and in the water line may cause some ignition delay. In that case, repeat the ignition process until all the air has been purged.

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Operation instructions

4.4

Setting the water temperature

The GWH 1600 H has a gas control that modulates burner input in response to flow. Its purpose is to ensure that the hot water temperature will remain steady, although the water flow demand might vary. The output temperature can be adjusted with either the temperature adjustment knob or the gas control knob.

Temperature adjustment knob

The temperature adjustment knob on the front bottom of the heater (see Fig. 20) adjusts temperature by adjusting flow capacity. See table 4 for details.

4.5

Power adjustment

Less power.

Lower water temperature.

Fig. 21

More power.

Higher water temperature.

Fig. 20

Knob position

Degree rise

Clockwise

90°F

Counterclockwise

45°F

Activation rate 0.5 GPM 1.1 GPM

Max flow rate

Table 4 Clearances

2.0 GPM 3.7 GPM

As the temperature adjustment knob is turned counterclockwise, the output temperature will lower and the activation rate will be raised. Turning the knob clockwise will raise the temperature and lower the activation rate.

Fig. 22

4.6

Purge the appliance

If there is a risk of freezing, proceed as follows:

B Remove the retaining clip from threaded bushing

(pos. 1).

B Remove threaded bushing (pos. 2) from water valve.

B Empty the appliance of all water.

Fig. 23 Purge

1

2

Retaining clip

Threaded bushing

16

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Maintenance and service

5 Maintenance and service

5.1

Maintenance intervals

Warning: Failure to perform recommended maintenance may result in complete failure of the unit over time.

The warranty does not cover failures due to improper or insufficient maintenance.

The GWH 1600 H requires periodic maintenance. The below time maintenance intervals should keep the unit operating for many years.

Every year

B Inspect inlet water filter screen ( 5.2)

B Inspect pilot assembly and flame ( 5.3)

B Inspect burner assembly ( 5.4)

Every 2 years

B Lubricate and clean water valve ( 5.2)

Every 3 to 5 years

B Rebuild water valve ( 5.2)

B Clean pilot assembly and clean or replace orifice

( 5.3)

5.2

Water valve

The water valve is the main control that tells the heater to fire. If the periodic maintenance is neglected, more costly damage may occur over time.

Inspecting inlet water filter screen

Shut off the installer supplied cold water isolation valve to the heater. If one is not installed, install before proceeding. Open the nearest hot water tap to drain the plumbing lines. Position a bucket under the heater's water valve assembly to catch any water that may drain from the heater. Remove the filter retaining clip located at base of water valve (see Fig. 23). Remove the threaded bushing to access the cylindrical filter inside.

Remove filter, clean with water and inspect for damage.

If the filter is at all damaged, it should be replaced.

Lubricating the water valve

A more detailed instruction is available on our website at www.boschhotwater.com. Shut off the installer supplied cold water isolation valve to the heater. If one is not installed, install before proceeding. Open the nearest hot water tap to drain the plumbing lines.

Position a bucket under the heater's water valve assembly to catch any water that may drain from the heater. Disconnect the inlet water pipe going to the back of the water valve. Disconnect the water pipe leading out of water valve to the heat exchanger. Do this by removing the retaining clip on water valve assembly and pulling the pipe free from the water valve. Loosen the two set screws at the bottom of the water valve where it connects to the gas valve. If the set screws are seized, STOP and call Bosch tech support before proceeding. Forcing and snapping seized set screws may cause irrevocable damage to the water valve and gas valve assemblies. Remove the water valve by pulling it to the right. Separate the two halves of the water valve by removing the five screws on the left side of the water valve. Apply lithium or faucet & valve grease to the pushrod and o-ring. (See Fig. 25, num. 23).

Inspect the venturi and clean if necessary. (see Fig 27, num. 23).

Rebuilding the water valve

Several parts within the water valve should be replaced every 3 to 5 years depending on water quality and usage. The parts list and instructions can be found on our website at www.boschhotwater.com. Failure to rebuild the water valve can result in decreased performance or damage to the heater.

5.3

Pilot

Inspecting pilot

The pilot should burn with a clean sharp blue flame. The flame should fully engulf the tip of the thermocouple. If it does not, clean the pilot assembly per procedure below.

Cleaning pilot assembly

Shut off gas supply to the heater using installer supplied manual gas shutoff. Locate pilot gas tubing mounted in the center of the burner assembly. At the base of the pilot gas tubing there is a retaining clip. Release pilot gas tubing from this clip. Push upwards on other end of pilot gas tubing to release it from burner mount.

Remove brass hex headed pilot orifice from gas valve

(located near base of pilot gas tubing). Soak orifice and pilot gas tubing in carburetor cleaner for 30 minutes.

Dry off and reinsert orifice in gas valve. If heater is an LP unit, replace orifice. Reinstall the pilot gas tubing following removal instructions in reverse. Open gas supply and return heater to service.

Caution: Do not ream or poke orifice as it will enlarge orifice opening.

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Maintenance and service

5.4

Main burners

The main burner flames should be blue, with a more intense blue cone in the center core. Yellow flames could be a sign of wrong size gas orifices or dirty burners, a blockage on the heat exchangers fins. If some burners have yellow flames while others have blue flames, it is likely that dust, lint or spider webs have partially clogged the burner venturis. To clean the burners, contact a gas service person.

5.5

Vent assembly

Inspect the draft hood and heat exchanger fins for signs of soot build-up or any other foreign material such as spider webs. Clean out any debris found in the vent hood. Signs of soot indicate insufficient combustion air or exhaust draft. Check for vent assembly blockage or combustion air blockage on the underside of the unit.

5.6

Mineral scale build-up

The GWH 1600 H, when operated at lower temperatures settings, does not accumulate mineral build-up. If however, the heater is used at the higher temperature settings and the water has a high mineral content, periodic descaling may be necessary. The heating coils should be flushed with a descaling solution.

5.6.1

Descaling heat exchanger

1. Disconnect electrical supply from the water heater.

2. Shut off the water supply to the water heater using

(installer supplied) isolation valve.

3. Open hot water taps to drain and relieve pressure from the plumbing system.

4. Drain water from the unit's heat exchanger by disconnecting inlet and outlet water connections.

5. Connect the line (A) from the outlet of the circulating pump (installer supplied) to the inlet water fitting on the water heater.

6. Using another line (B), connect to the water outlet fitting on the water heater. Route the other end of this line into a descaling reservoir.

7. Using a 3rd line (C) from the descaling reservoir, connect to the inlet side of circulating pump. Verify there is a filter on the end of the line in the descaling reservoir.

8. Make sure all connections are "hand tight."

9. Fill tank with descaling solution so lines inside are submersed. We recommend a straight white vinegar solution. If using a commercial descalant, refer to manufacturer's instructions on dilution with water.

10. Operate the circulating pump.

11. Make sure there are no leaks and the solution is flowing from the descaling reservoir through the heat exchanger and returning to the reservoir.

12. Run solution through the heat exchanger until the solution returning to the descaling reservoir comes out clear. (Changing to a fresh solution may be necessary during this process).

13. Disconnect all lines and drain all solution from heat exchanger. Properly discard of solution.

14. Position a container below the hot water outlet and connect cold water supply. Open cold water supply isolation valve and flush heat exchanger with clean water.

15. Shut cold water isolation valve and reconnect hot water supply to the water heater.

16. Reconnect electrical supply to unit, open water isolation valves, and return the unit to service.

Fig. 24

18

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Troubleshooting

6 Troubleshooting

6.1

Introduction

Many of the questions customers ask regarding operation of this unit can be answered by following the troubleshooting steps as outlined below. Visit our web site at www.boschhotwater.com for more detailed troubleshooting. For best results, perform each step before proceeding to the next. The suggested solutions may require that the cover be taken off (See chapter

3.4).

6.2

No spark at pilot with water flow

• 1. Verify the ON/OFF button, located behind the flip down cover plate, is completely depressed in the ON position (Position

Fig. 17.

). See chapter chapter 4.2,

• 2. Verify the cold water supply is connected to the right side rear of the water valve.

• 3. Close installer supplied cold water shut off valve (if none installed, install before proceeding). Open all hot water taps supplied by the heater. Wait 5 minutes and check all taps. Any water running is a sign of a plumbing crossover. Consult a local plumber or service person for help in correcting a plumbing crossover.

• 4. Confirm that there is an adequate flow rate. With the temperature adjustment knob on the unit positioned all the way clockwise, a 1/2 gallon per minute (GPM) flow rate is required for heater activation. Fully open a hot water faucet and fill a quart container. If the container fills in 30 seconds or less, the flow rate (1/2 GPM) is sufficient to activate the water heater.

NOTE: When the dial is turned all the way counterclockwise, a flow rate of 1.1 GPM is required for heater activation.

• 5. Inspect the water path for obstructions. Make sure all outlets (i.e. showerheads, faucet aerators and whole house filters) are clear of debris. Inspect and clean the water heater's inlet filter screen. See chapter 5.2.

• 6. Verify all wire connections are secure, paying close attention to the wire connection between the piezzo electrode and the electronic control box.

• 7. Check for voltage at the hydro-generator.

Disconnect plug connector on wires leading from hydro-generator (approximately 3" from hydrogenerator). Verify voltage on hydro-generator side of plug connector with hot water running. The voltage reading should be 1.6VAC or greater. If voltage is lower, then remove and flush the hydro-generator.

Reinstall hydro-generator and take another voltage reading. If voltage is at least 1.6VAC, proceed to next step. If voltage is still low, hydro-generator may be damaged/defective. Visit www.boschhotwater.com

to purchase replacement part, or call Bosch Water

Heating at 800-642-3111 for replacement part if still under warranty.

• 8. If using a power vent, check the safety spillage switch reset button (the safety spillage is wired through the water heater's thermocouple circuit).

The safety spillage switch should be located at the top of the water heater close to the draft diverter.

Consult power vent manual for more detailed instructions.

• 9. Verify the spade connectors on the two overheat sensors (ECO) & the flue gas sensor are plugged in securely and their terminals are free of corrosion. The terminals can be cleaned with a pencil eraser. The

ECO's are located on the lower left hot water outlet pipe and the upper right side of heat exchanger. The flue gas sensor is located on the upper right side of draft diverter.

• 10. Verify the microswitch located on bottom of gas valve is firmly mounted and wire clip connector is secure.

• 11. Electronic control box may be damaged or defective. Visit www.boschhotwater.com to purchase replacement part, or call Bosch Water

Heating at 800-642-3111 for replacement part if still under warranty.

6.3

Spark appears when hot water is turned on, but pilot and burners will not ignite

• 1. Verify gas type indicated in the rating sticker located on the cover's right hand side, coincides with the gas type you are using. NG is a natural gas unit and LP is for liquid propane (see chapter 2.2).

• 2. If the unit was just installed or the gas lines have been worked on, there may be air in the gas line.

Bleed out the air trapped in the gas line by turning the hot water faucet on and off until the pilot flame/ burners ignite. (Please note: depending on how much air is in the line this could take numerous cycles of turning the faucet on and off).

• 3. Verify gas supply is on at Natural Gas meter or

Propane tank. Make sure all manual gas shut off valves are open.

• 4. Have a licensed gas technician confirm adequate gas pressure at the inlet tap (See gas requirements in chapter 2.1). If gas is not present, verify manufacturer supplied Maxitrol regulator is in the upright position. The arrow on the back of the regulator should point in the same direction as gas flow.

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Troubleshooting

• 5. Confirm wire connection to the pilot electro valve is secure. See Components Diagram for location.

Inspect terminals for corrosion. To clean terminals, remove the spade connectors and clean with a pencil eraser

• 6. Open a hot water faucet. While sparking, hold a flame from a lit match or lighter in the pilot area. If the pilot successfully lights, the pilot orifice may be dirty or clogged. See chapter 5.3 on how to clean the pilot

• 7. Verify adequate voltage at the spade connection of the pilot electro valve. When sparking, voltage should read 1.6VAC. If voltage is proper, pilot electro valve is defective. If voltage is not proper, electronic control box is defective.

Visit www.boschhotwater.com to purchase replacement part, or call Bosch Water Heating at

800-642-3111 for replacement part if still under warranty.

6.4

Pilot light, but burners will not come on.

• 1. Verify gas type indicated in the rating sticker located on the cover's right hand side, coincides with the gas type you are using. NG is a natural gas unit and LP is for liquid propane (See chapter 2.2).

• 2. Pilot flame should be blue in color and completely engulfing the flame sensor. If not, the pilot orifice may be dirty or clogged. See chapter 5.3 on how to clean the pilot.

• 3. Flame sensor not recognizing pilot flame. Verify wire connection clip on wire from the bottom of the flame sensor is secure. If flame sensor is fully engulfed by the pilot flame, it may be dirty. Clean entire surface area of flame sensor with a pencil eraser.

• 4. Inspect the water path for obstructions. Make sure all outlets (i.e. showerheads, faucet aerators and whole house filters) are clear of debris. Inspect and clean the water heater's inlet filter screen. See chapter 5.2.

• 5. Confirm wire connection to the burner electro valve is secure (see components diagram for location of burner electro valve). Inspect terminals for corrosion. To clean terminals, remove the spade connectors and clean with a pencil eraser.

• 6. The water valve assembly, which allows gas flow to the burners, requires periodic maintenance (every

2-5 years depending on water quality and use). Visit www.boschhotwater.com to purchase water valve rebuild kit to service the water valve

• 7.Electric control box, burner electro valve or flame sensor maybe damaged/defective. Verify adequate voltage at the spade connection of the burner electro valve (see components diagram for location of burner electro valve). After the pilot lights, voltage should read 1.6VAC on the burner electro valve. If voltage is proper, the burner electro valve is defective. If voltage is not proper, electronic control box or the flame sensor is damaged/defective.

Visit www.boschhotwater.com to purchase replacement part, or call Bosch Water Heating at

800-642-3111 for replacement part if still under warranty.

Fig. 25 Electrical wiring diagram

27

28

31

32

2

3

23

25

34

50

51

110

111

Pilot electrode

Flame sensor

Electronic control box

Burner electro valve

Gas control valve

Pilot electro valve

Temperature limiter

Flue gas safety device

LED indicator main burner operation

Hydro-generator

On/Off switch

LED failure control box

Overheat limiter

6.5

Main burners go out during hot water use

• 1. Hot water flow rate is dropping below required activation flow rate. Turn temperature adjustment knob all the way clockwise. Fully open a hot water faucet and fill a quart container. If the container fills in

30 seconds or less, the flow rate (1/2 gallon per minute) is sufficient to activate the water heater. If flow rate is not sufficient, the water heater's inlet filter should be inspected and cleaned. See chapter 5.2.

• 2. Close installer supplied cold water shut off valve (if none installed, install before proceeding). Open all hot water taps supplied by the heater. Wait 5 minutes and check all taps. Any water running is a sign of a plumbing crossover. Consult local plumber or service person for help correcting a plumbing crossover.

• 3. The minimum water pressure for the home should be 30psi or greater. For installation on a private well system with use of a pressure tank, the lowest pressure range setting recommended is 30-50 psi

(2.07-3.45 bar).

20

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Troubleshooting

• 4. Hot water is very hot out of the tap, requiring a lot of cold water to be added with it in order to attain a useable hot water temperature. The addition of too much cold will overpower and slow the flow within the tankless heater, decreasing it below activation point, which shuts off the burners. The end result is nothing but cold water coming out of the outlet.

Reduce the need for cold water mixed by turning the power adjustment knob clockwise for lower hot water temperatures. See chapter 4.4 and 4.5 for details in lowering temperature. If the problem persists, go to www.boschhotwater.com for a more detailed service bulletin on this problem.

• 5. The overheat sensor (ECO) is tripped. The water heater does not have a thermostat. If the inlet water is preheated, the unit will overheat, stopping the flow of gas. Plumb inlet with cold water only.

• 6. Flue gas sensor is tripped. Lack of adequate combustion air or failure to vent properly by reducing pipe diameter, improper use of elbows or exceed maximum vent length will interrupt the flue gas sensor circuit. Confirm venting and combustion air is in accordance with requirements in this installation manual

• 7. If the water has a high mineral content, the heat exchanger may be scaled internally. This restricts the water path, causing the water to overheat and trip the overheat sensor (ECO) shutting all gas flow. To descale the heat exchanger, consult service bulletins on www.boschhotwater.com

• 8. The water valve assembly, which allows gas flow to the burners, requires periodic maintenance (every

2-5 years depending on water quality and use). Visit www.boschhotwater.com to purchase water valve rebuild kit to service the water valve.

6.6

Hot water temperature fluctuates at tap

• 1. Close installer supplied cold water shut off valve (if none installed, install before proceeding). Open all hot water taps supplied by the heater. Wait 5 minutes and check all taps. Any water running is a sign of a plumbing crossover. Consult local plumber or service person for help correcting a plumbing crossover.

• 2. Check for a clogged inlet water filter screen. See chapter 5.2.

• 3. Hot water is very hot out of the tap, requiring a lot of cold water to be added with it in order to attain a useable hot water temperature. The addition of too much cold will overpower and slow the flow within the tankless heater, decreasing it below activation point, which shuts off the burners. The end result is nothing but cold water coming out of the outlet.

Reduce the need for cold water mixed by turning the power adjustment knob clockwise for lower hot water temperatures. See chapter 4.5. If the problem persists, go to www.boschhotwater.com for a more detailed service bulletin on this problem

• 4. The water heater is designed to modulate gas flow to the burners when water flow varies. If the water pressure in the home is erratic and the water flow is not consistent while a tap is opened, then the temperature of the hot water will fluctuate. The minimum water pressure for the home should be

30psi or greater. For installations on a private well system with the use of a pressure tank, the lowest pressure range setting recommended is 30-50psi

(2.07-3.45 bar). The use of a pressure reducing/ regulating valve before the water heater (directly after the pressure tank on well systems) is an effective way to maintain constant water pressure to the water heater. Watts brand 25AUB-3/4" or N35B-3/4" pressure reducing/regulating valves or equivalent are suggested.

• 5. If the inlet water temperature is not steady then the hot water temperature from the water heater will fluctuate. The water heater modulates its burners when flow rate is changed. It does not have a thermostat and will not adjust to changes in inlet water temperature.

• 6. If the inlet water temperature to the water heater is above 70 F, the heater may produce outlet temperatures that are too hot for most users. A temperature balance shower valve can automatically mix in cold water to reduce such hot water temperature. This can slow the flow within the tankless water heater, decreasing it below activation point, which shuts off the burners. In the event of any temperature instability with the use of a temperature balance shower valve, refer to shower valve manufacturer instructions for internal adjustment setting. An adjustment should be made to minimize the amount of cold water the valve is adding.

• 7. The gas pressure also needs to be stable and adequate. Ensure gas pressure is in accordance with specifications in the installation manual. See chapter 3.9. A gas pressure reading is needed to proceed further. Contact your original installer or a local certified gas technician to obtain this reading.

6.7

Water is too hot

• 1. Verify gas type indicated in the rating sticker located on the cover's right hand side, coincides with the gas type you are using. NG is a natural gas unit and LP is for liquid propane (See chapter 2.2).

• 2. Adjust the power adjustment knob clockwise for cooler temperatures. If the water is still too hot, the temperature adjustment knob maybe set too high.

Lower the setting and test the water temperature.

This dial turns counterclockwise for lower temperatures and clockwise for higher temperatures.

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Troubleshooting

• 3. Inlet water is preheated. This model does not have a thermostat and will not modulate flame height in order to prevent overheating. It is designed for a cold water feed only. Replumb the heater with cold water to the inlet.

• 4. Increase flow rate. Restrictions in the water path can slow the flow of water through the heater, resulting in very hot outlet temperatures. Restrictive showerheads and faucet aerators should be cleaned out or upgraded with less restrictive ones. In addition, the inlet filter on the water heater should be cleaned and inspected. See chapter 5.2.

• 5. If water is still too hot, consult service bulletins on www.boschhotwater.com to lower outlet temperatures further.

• 6. If the water has a high mineral content, the heat exchanger may be scaled internally. This restricts the water path, causing the water to boil and produce extremely hot temperatures. To descale the heat exchanger, consult service bulletins on www.boschhotwater.com.

6.8

Water is not hot enough

• 1. Verify gas type indicated in the rating sticker located on the cover's right hand side, coincides with the gas type you are using. NG is a natural gas unit and LP is for liquid propane (see chapter 2.2).

• 2. Flow at one particular tap is too great or too many fixtures are running at one time. Lower flow to stay within heater's specifications.

• 3. Ensure the power adjustment knob is all the way clockwise for highest temperatures. In addition, the temperature adjustment knob maybe set too low.

Raise the setting and test the water temperature.

This dial turns counterclockwise for lower temperatures and clockwise for higher temperatures.

• 4. Close installer supplied cold water shut off valve (if none installed, install before proceeding). Open all hot water taps supplied by the heater. Wait 5 minutes and check all taps. Any water running is a sign of a plumbing crossover. Consult local plumber or service person for help correcting a plumbing crossover.

• 5. Inspect the water path outside the heater for obstructions. Make sure all outlets (i.e. showerheads, faucet aerators and whole house filters) are clear of debris. Also, the water heater's inlet filter should be inspected and cleaned. See chapter 5.2.

• 6. The water valve assembly, which allows gas flow to the burners, requires periodic maintenance (every

2-5 years depending on water quality and use). Visit www.boschhotwater.com to purchase water valve rebuild kit to service the water valve.

• 7. Gas pressure is too low. Ensure gas pressure is in accordance with specifications in the installation manual. See chapter 3.9. A gas pressure reading is needed to proceed further. Contact your original installer or a local certified gas technician to obtain this reading.

6.9

Burners ignite without water flow

• 1. The water valve may be dirty and sticking, prohibiting it from fully closing the gas valve. This part requires periodic maintenance (every 2-5 years depending on water quality and use). Visit www.boschhotwater.com to purchase water valve rebuild kit to service the water valve.

6.10 Low hot water pressure

• 1. Confirm adequate flow rate through the unit. With cold supply shut off to the unit, disconnect hot outlet side to the unit. Place a gallon jug under hot water outlet to catch water. Open cold water supply and measure flow rate out of the unit. With temperature adjustment knob set all the way clockwise, the flow rate should be close to 2GPM (filling the jug in 30 seconds or less). If the flow rate is not adequate, inspect and clean inlet filter screen. See chapter 5.2.

• 2. Confirm the incoming water pressure to the unit is above the required 30psi.

• 3. Inspect the water path outside the heater for obstructions. Make sure all outlets (i.e. showerheads, faucet aerators and whole house filters) are clear of debris.

• 4. Be sure to run only one major fixture at a time with this water heater. Opening too many taps at one time can disperse water flow resulting in diminished flow/ pressure at all outlets.

• 5. If the water has a high mineral content, the heat exchanger may be scaled internally. This restricts the water path, causing diminished water flow. To descale the heat exchanger, consult service bulletins at www.boschhotwater.com.

6.11 Noise when heater is running

• 1. Confirm adequate flow rate through the unit. With cold supply shut off to the unit, disconnect hot outlet side to the unit. Place a gallon jug under hot water outlet to catch water. Open cold water supply and measure flow rate out of the unit. With temperature adjustment knob set all the way clockwise, the flow rate should be close to 2GPM (filling the jug in 30 seconds or less). If the flow rate is not adequate, inspect and clean inlet filter screen. See chapter 5.2.

• 2. Inspect the water path for obstructions. Make sure all outlets (i.e. showerheads, faucet aerators and whole house filters) are clear of debris. Restrictions

22

6 720 608 032

Protecting the environment in the water path can slow water flow through the heat exchanger causing it to boil and make noise

• 3. If the water has a high mineral content, the heat exchanger may be scaled internally. This restricts the water path, causing the water to boil resulting in noise and overheating. To descale the heat exchanger, consult service bulletins on www.boschhotwater.com.

6.12 Burners do not burn cleanly, yellow flames when operating

• 1. Verify gas type indicated in the rating sticker located on the heater's right hand side, coincides with the gas type you are using. NG is a natural gas unit and LP is for liquid propane (see chapter 2.2).

• 2. Gas pressure may be inadequate resulting in improper combustion. Ensure gas pressure is in accordance with specifications in the installation manual. A gas pressure reading is needed to proceed further. Contact your original installer or a local certified gas technician to obtain this reading.

See chapter 3.9.

• 3. For proper combustion at high elevations the inlet gas pressure should be set at installation to the values in table 3 on page 11 (while operating at maximum BTU). A gas pressure reading is needed to proceed further. Contact your original installer or a local certified gas technician to obtain this reading.

• 4. Ventilation is not adequate. Ensure adequate combustion air is being supplied to the unit in accordance with requirements in the installation manual. See chapter 3.6.

• 5. Verify the water heater is vented properly. Ensure the venting is in accordance with requirements in the installation manual. See chapter 3.7.

• 6. The water heater has burners much like a furnace.

It is essential that they remain clean and are supplied with adequate air for combustion. If the flames burn yellow or orange it is strongly recommended that the burners be removed from the unit and cleaned. Once the burners are removed, the fins in the top of the heat exchanger can be accessed and brushed or vacuumed clean. Consult service bulletins on www.boschhotwater.com for removing/cleaning the burners.

7 Protecting the environment

Packing

The packing box may be fully recycled as confirmed by the recycling symbol .

Components

Many parts in the heater can be fully recycled in the end of the product life. Contact your city authorities for information about the disposal of recyclable products.

Saving water resources:

B Make sure you close all the taps after any use. Avoid leaving the taps dripping. Repair any leaking tap.

B Define the temperature you want. This way you have the precise water flow needed (mixing cold water to regulate temperature will increase the water flow with consequent waste of water).

For increased safety shut off the appliance from the main water supply if your are staying away from home for a considerable time.

At below freezing temperatures, disconnect the plumbing connections to the heater and allow the heater to drain.

To prevent any freeze damage, introduce short bursts of compressed air (20-40 psi) through these connections to remove the residual water in the horizontal pipes and water valve.

Follow instructions in chapter 4.5 to remove any additional water remaining in the watervalve and heat exchanger.

6 720 608 032

23

Interior components and diagram parts list

8 Interior components and diagram parts list

8.1

Interior components

Fig. 26 Functional scheme

4

5

9

10

11

22

Heat exchanger

Main gas burner

Electronic control box

Temperature adjustment selector

Water valve

Flexible hot outlet

24

26

30

51

Output control

Pilot gas tubing on/off switch

6 720 608 032

Interior components and diagram parts list

8.2

Components diagram

7

8

6

3

2

4

5

10

36

39

42

24

33

40

35

15

16

18

19

17

20

14

13

43

28

21

22

9

1

29

30

11

12

44

25

23

26

27

24

37 38

34

41

32

6720608032-07.1 JF

Fig. 27 Components Diagram

6 720 608 032

25

Interior components and diagram parts list

8.3

Parts list

Item

31

32

33

34

27

28

29

30

22

22

23

24

25

26

19

20

20

21

41

42

43

44

35

36

37

38

39

40

16

17

18

19

11

12

13

13

14

15

7

8

5

6

9

10

3

4

1

2

Table 5

Description

Front cover

Shield

Control cover

Temp. control knob

Water flow selector handle

Draft Diverter

Exhaust pipe union Ø128

Angle bracket

Cover retaining clip (x10)

Heat exchanger

Hydro generator

Cold water pipe

Main burner LP

Main burner NG

Connector

Pilot burner

Sparking plug

Ignitor bracket (x10)

Pilot screen

Gas valve LP

Gas valve NG

Pilot injector LP

Pilot injector NG

Microswitch

Gas pressure regulator LP

Gas pressure regulator NG

Water valve

Watervalve pushrod (10x)

Diaphragm (L)

Inlet water connection

Selector screw

Ignition unit

Cable

Flue gas safety device

Heat exchanger washer

Threaded bushing

Connector

Water filter

Outlet Hose

Water connection clip

Plunger

Volumetric water governor

ECO

Temperature limiter

Venturi

Hot water pipe

Gas supply pipe

Cover

Reference

8 707 011 976 0

8 708 200 321 0

8 708 200 322 0

8 707 200 020 0

8 707 406 083 0

8 707 406 084 0

8 707 006 344 0

8 703 204 051 0

8 700 503 084 0

8 700 306 110 0

8 708 500 304 0

8 707 207 142 0

8 704 401 340 0

8 707 206 446 0

8 700 103 658 0

8 700 306 148 0

8 700 306 187 0

8 700 507 059 0

8 705 431 242 0

8 705 506 814 0

8 705 506 813 0

8 702 000 305 0

8 702 000 304 0

8 705 505 442 0

8 705 504 046 0

8 708 003 192 0

8 700 506 200 0

8 705 406 332 0

8 707 406 071 0

8 700 715 109 0

8 708 120 615 0

8 708 120 616 0

8 705 209 056 0

8 708 105 655 0

8 708 107 013 0

8 701 300 010 0

8 700 507 066 0

8 707 011 962 0

8 700 703 139 0

8 701 201 020 0

8 703 502 039 0

8 705 705 034 0

8 707 206 017 0

8 707 206 132 0

8 708 205 279 0

8 700 715 178 0

8 700 715 351 0

8 705 500 105 0

26

6 720 608 032

Twelve Year Limited Warranty

9 Twelve Year Limited Warranty

General

Aquastar water heaters are warranted by the

Manufacturer (BOSCH) through BBT North America.

BBT North America (BBTNA) will furnish a replacement heat exchanger and will furnish a replacement of any other part which fails in normal use and service within the applicable periods specified below, in accordance with the terms of this warranty. The BBTNA replacement will be warranted for the unexpired portion of the original warranty. This warranty will be valid only for water heaters in possession of the original purchaser as recorded on the warranty card.

The Heat Exchanger

If the heat exchanger fails within twelve (12) years after the original installation and operation BBTNA will furnish a replacement heat exchanger. However, if the water heater is installed in other than a single family dwelling this heat exchanger warranty is limited to two

(2) years from date of original installation and operation.

Exceptions

This warranty will not apply:

1. to defects or malfunctions resulting from failure to properly install, operate or maintain the unit in accordance with the printed instructions provided;

2. to damage or abuse, accident, neglect or freezing and other acts of nature;

3. to damage resulting from operation with either the flame sensor rod or overheat sensor removed;

4. to failure of the heat exchanger resulting from the operation of the water heater in a corrosive atmosphere or at water temperatures exceeding the maximum rating, or if the water heater is not supplied with potable water;

5. to defects or damage cause by any attachment or modification, including any energy-saving device.

All Other Parts

If any other part fails within two (2) years after original installation and operation, BBTNA will furnish a replacement part free of charge.

Shipping costs

In addition to supplying the replacement part(s),

BBTNA will provide ground service delivery for these parts. Expedited or upgraded shipping will be charged to the customer.

Service Labor Costs

This warranty does not cover any labor costs associated with service, removal or re-installation of part(s). All such costs must be borne by the Purchaser.

Additionally, this warranty does not cover any labor costs associated with service, removal or re-installation of the original water heater or a replaced water heater.

i Note: the water heater must be free of damaging scale deposits and not subject to gas pressures greater than those shown on the rating plate, which must not be altered, defaced or removed.

How to Make a Claim

Any claim for warranty parts should be made to your local dealer, distributor or to BBTNA. If BBTNA, please contact the Technical Support Department:

BBT NORTH AMERICA

Bosch Group

340 Mad River Park

Waitsfield, VT 05673

Phone: 800-642-3111 www.boschhotwater.com

In most cases, the dealer or distributor will be able to promptly honor your claim and subsequently notify

BBTNA. However, all replacements are made subject to validation by BBTNA of in-warranty coverage. The damaged or defective item must be made available in exchange for the replacement.

Miscellaneous

No one is authorized to make any other warranties on behalf of BBTNA. It is expressly understood that the replacement warranty of BBTNA shall be in lieu of any and all other warranties, express or implied, including warranties of merchantability or fitness for a particular use or purpose, and further that BBTNA shall not be liable for any loss or damage directly or indirectly arising from the use of the hot water heater, or for any consequential damages arising from such use

(including damages from water leakage). BBTNA sole liability with respect to any defect shall be for the replacement of the defective part(s). Some states do not allow such limitations and exclusions, so the above may not apply to you.

This warranty gives specific legal rights. You may also have other rights which vary from state to state.

27

6 720 608 032

Installer Checklist, to be performed by installer upon installation

Serial Number ___ ___ ___ ___ ___ ___ ___ ___

(8 digit serial number is located on rating plate on right side panel)

Gas Pressure Reading*

Building Water Pressure

Average Winter Temperature

Average Summer Temperature

Installing Company

Installer name

Address

Phone

Static__________

__________

__________

Operating__________

__________ Range if on Well system __________

_____________________________________________

_____________________________________________

_____________________________________________

_____________________________________________

* See Chapter 3.8 and gas pressure table (to be filled out by installer)

Installation manual should be left with the owner after the installation is tested and completed

BBT NORTH AMERICA

Bosch Group

Bosch Water Heating

340 Mad River Park

Waitsfield, VT 05673

Phone 800-642-3111

Fax 802-496-6924 www.boschhotwater.com

[email protected]

Recycled paper

VULCANO Termodomésticos S.A.

Estrada de Cacia

3801 - 856 Aveiro - PORTUGAL

© 2006 BBT NORTH AMERICA CORPORATION,

Waitsfield, VT all rights reserved

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