Bosch 7701331614 Natural Gas Continuous Flow Hot Water System

Technical Characteristics and Dimensions

Dimensions

Functional diagram of the heater

1. Pilot burner
2. Ignition Electrode
3. Ionisation probe
4. Heat exchanger
5. Main burner
6. Injector
7. a Burner pressure test point
   7.b Gas inlet pressure test point
8. Slow ignition valve
9. Venturi
10. Temperature/volume selector
11. Water valve
12. Plunger
13. Water flow regulator
14. Water filter
15. Hydrogenerator
16. Cold water pipe
17. Diaphragm
18. Main gas valve
19. Maximum gas adjusting screw
20. Gas supply pipe
21. Gas filter
22. Hot water pipe
23. Ignition unit
24. Temperature sensor
25. Servo valve
26. Power selector
27. Gas valve
28. Pilot valve
29. Pilot injector
30. Pilot gas pipe
31. Overtemperature switch
32. Flue gas safety device
33. Relief Valve/Drain screw

Electrical diagram

Function

This gas heater is equipped with automatic electronic ignition to simplify operation.

► To activate, just turn on the switch (Fig. 8).

After this, automatic ignition occurs whenever a hot water tap is opened. First, the pilot burner is lit and approximately four seconds later the main burner ignites. The pilot burner flame is extinguished after the main burner lights.

This is a way of saving a great amount of energy as the pilot burner only operates for the minimum necessary time to ignite the main burner.

Regulations

Any local by-laws and regulations pertaining to installation and use of gas-heated appliances must be observed.

This appliance must be installed in accordance with the manufacturers installation instructions, AS5601, NZ5261 and all Local Building & Gas fitting regulations

It is recommended that for sanitary fixtures used for the purpose of personal hygiene, that a temperature limitingl device be fitted (such as a tempering valve) as per AS3498.

This appliance must not be installed in a bedroom, bathroom, toilet, or combined living/sleeping room as per AS5601 5.12.5.2

Failure to install this appliance in accordance with these installation instructions will void the warranty.

Installation

Selection of the place of installation

Requirements regarding the place of installation

• Comply with the specific instructions for each State.
• Install the gas heater in a well-ventilated location where it will not be exposed to temperatures below zero. Ensure combustion gases are flued to outside atmosphere in accordance with AS5601.
• To avoid corrosion, the combustion air must be free from harmful substances. Examples of particularly corrosive substances: halogenated hydrocarbons contained in solvents, paints, glues, hairsprays and various domestic detergents. If necessary, take adequate measures.
• Install the appliance in accordance with the minimum installation clearances indicated in Fig. 4.
• The gas heater must not be installed over a heat source.
• Do not obstruct the openings at top and bottom of appliance.
• Top and bottom areas must be clear from any obstacles at least 30 cm.

In case of a frost risk:

• Turn off the heater.
• Drain the heater (see section 5.7)

Surface temperature

The maximum surface temperature of the heater is less than 85 °C, with the exception of the flue piping. No special protection measures are required for flammable construction materials or built-in furniture items.

Air intake

The place where the heater is to be installed must have an adequate air supply as per AS5601.

Heater mounting

• Remove the temperature/flow selector and the gas selector knobs.
• Unscrew the cover fixing screws.
• With a simultaneous movement forwards and upwards, release the cover from the two lugs at the back.
• Fix the heater vertically, using the provided screw hooks and plugs or use fixings appropriate for the material & weight.

Water connection

It is advisable to purge the water pipes before connection, because the presence of dirt may reduce the flow and, in extreme cases, cause a blockage.

• Identify the cold water pipe (Fig. 5, item A) and the hot water pipe (Fig. 5, item B), so as to avoid any possible cross-connection.
• Connect the water pipes to the water valve using the connection accessories provided.

CAUTION:

If fitting an isolating valve to the water inlet line it must be a Gate or Ball Valve, a Stop Cock or Non-Return Valve must not be fitted.

Hydrogenerator operation

The hydrogenerator (hydrodynamic generator or HDG) is located in the water circuit between the water valve and the heat exchanger. This component has a turbine that rotates when water flows past its blades. This movement is transmitted to an electric generator which powers the heater ignition unit.

The electrical voltage value supplied by the HDG is approximately 3.0 VAC.

Pressure Relief

The pressure relief (Fig. 2, pos. 33) will release pressure from the system whenever the value exceeds 1500 kPa.

Gas connection

Gas regulator

The appliance is supplied with a gas pressure regulator that must be installed on the heater before attaching the gas supply line (see Fig. 6).

• Use sealing tape to assure the complete tightness of the installation.

Testing

• Turn on the gas and water cocks and check all connections for leaks. If all connections are sound then follow procedures set out in Section 6 for adjustment of Gas Pressures.

Operating instructions

Digital display - description

1 Temperature/error code

2 Malfunction indicator

3 Temperature measurement units

4 Heater in operation (burner turned on)

Before starting up the heater

• Check if the gas indicated on the rating plate is the same as the one used at the location.
• Open the gas valve.
• Open the water valve.

Turning the heater on and off

Turning on

• Press the switch , position.

Turn Hot Tap on, LED light on = Main burner on

Turning off

• Press the switch , position

Water flow

If the red LED starts flashing during operation, check the water flow.

Gas adjustment

Lower water temperature. Use less gas.

Higher water temperature. Use more gas.

Temperature/flow adjustment

• Turn anti-clockwise

Increases flow and decreases water temperature.

• Turn clockwise.

Decreases flow and increases water temperature.

Regulating the temperature to the minimum required value reduces energy consumption.

Draining the appliance

There are two ways to drain the appliance if there is a risk of freezing.

After turning off the inlet water valve and gas supply, open a hot water tap to relieve pressure then proceed as follows:

Water valve draining (see fig 14)

• Remove the fixing lock from the filter screw cap (no. 1) situated in the water valve.
• Remove the filter screw cap (no. 2) from the water valve.
• Empty all the water contained in the heater.

1. Lock
2. Filter screw cap
3. Water valve

Cold water inlet pipe drain (see fig 15)

• Remove the pressure relief screw (no. 1) situated in the water inlet pipe.
• Drain all the water contained in the heater.

1. pressure relief screw

Commissioning

Inlet pressure adjustment

DANGER: The following procedures must only be performed by a qualified technician.

Burner pressures have been adjusted in the factory, however adjustment may be required upon installation.

Attach a manometer to the inlet pressure test point located on the gas inlet pipe.

Inlet gas pressure should be adjusted at the appliance regulator to 1.13 kPa for Natural Gas and 2.75 kPa for LP gas.

These measurements must be set while the unit is operating.

Burner pressure adjustment

Accessing the adjusting screw

• Remove the front cover from the heater (see 4.3).

Connecting the manometer

• loosen the burner test point captive screw (Fig. 16).
• Connect the manometer to the burner pressure measuring point.

Maximum gas flow adjustment

• Remove the seal from the adjusting screw (Fig. 17).
• Turn on the heater with the gas selector set to the left (maximum position).
  
• Open various hot water taps.
• Using the adjusting screw (Fig. 17), regulate the gas pressure until the values indicated in the table 6 are achieved.
• Seal the adjusting screw once again.

Minimum gas flow adjustment

The minimum gas flow adjustment is performed automatically after the adjustment of the maximum gas flow.

Table 6 Burner pressure

Conversion to a different type of gas

Only use original conversion parts.

The conversion must only be performed by a qualified technician. Original conversion kits are supplied with assembly instructions.

Maintenance

DANGER: Failure to perform maintenance procedures can lead to appliance malfunction, errors, service calls and loss of warranty.

To ensure that gas consumption and the environmental load (pollution, etc.) remain as negligible as possible over time, we recommend the appliance be maintained on an annual basis.

These jobs can only be done by a Bosch authorised service agent.

Maintenance must only be performed by a qualified technician. Maintenance information is contained in a service manual available to licenced technicians upon request from Bosch.

Flue gas safety device

DANGER: The probe must never be turned off, modified or replaced with a different part under any circumstances.

Operation and precautions

This probe verifies the condition of flue gas evacuation and, in case of malfunction, it automatically turns off the heater. This prevents combustion gases from entering the room where the gas heater has been installed. The probe restarts after a reset period.

If the heater turns off during operation:

• Ventilate the room.
• After 10 minutes, turn on the heater once again.

Call a qualified technician if the same thing happens again.

DANGER: The user must never touch the flue gas safety device

Maintenance*

If the probe malfunctions, proceed as follows:

• Unscrew the probe fixing screw.
• Detach the ignition unit terminal.
• Replace the faulty part and re-assemble in reverse order.

Operating check*

To check the correct operation of the flue gas safety device, proceed as follows:

• Remove the combustion gases flue pipe.
• temporarily replace it with a pipe (approximately 50 cm long) blocked at one end.
• The pipe must be installed vertically.
• Turn on the heater at nominal power and with the temperature selector adjusted to maximum temperature.

In these conditions, the heater must turn off no more than two minutes afterwards, at most. Remove the pipe and replace the flue pipe.

* These procedures must be performed by a qualified installer/service agent.

Problems

Problem/cause/solution

Assembly, maintenance and repairs must be performed by qualified technicians only. The following chart offers solutions to possible problems.

Environmental protection

Environmental protection is a basic company strategy of Bosch. The quality of our products, profitability and environmental protection are equal-ranking goals for us. Laws and regulations concerning environmental protection are strictly observed. We use the best possible technology and materials, under economic considerations, to protect the environment.

Packaging

We participate in the recycling program of the respective country to ensure optimal recycling. All of our packaging materials are environmental-friendly and can be recycled.

Old appliances

Old appliances contain valuable materials that should be recycled. The assemblies can be easily detached and synthetic materials are marked accordingly. The assemblies can therefore be sorted out and passed on for recycling or disposal.

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