VIESSMANN 7835343 Instantaneous Heating Water Heater Instruction Manual

VIESSMANN 7835343 Instantaneous Heating Water Heater

For the following heat pumps:

• Type BWT/BWT-M 221.A06 to A10
• Type BWT/BWT-M 241.A06 to A10
• Type BWT/BWT-NC 331.A06 to A10
• Type BWT 341.A06 to A10
• Type AWT-AC 221.A04 bis A13, B10, B13, B16
• Type AWT-AC 241.A04 bis A13, B10, B13, B16

Safety instructions

Please follow these safety instructions closely to prevent accidents and material losses.

Safety instructions explained

Danger
This symbol warns against the risk of injury.

Please note
This symbol warns against the risk of material losses and environmental pollution.

Note
Details identified by the word “Note” contain additional information.
Installation, commissioning, inspection, maintenance and repairs must only be carried out by a competent person (heating engineer/installation contractor).

Before working on the appliance/heating system, isolate the system from the power supply (e.g. by removing a separate mains fuse or by means of a mains isolator) and safeguard against unauthorised reconnection.

Note
In addition to the control circuit, there may be several power circuits (e.g. compressor, instantaneous heating water heater).

Danger
If not all electrical circuits are isolated, injury through electric shock and appliance damage may result.
Isolate all existing electrical circuits from the power supply and safeguard against reconnection.

Repairing components that fulfil a safety function can compromise the safe operation of your system.

For replacements, use only original spare parts supplied or approved by Viessmann.

Opening the heat pump

1. Isolate the system from the power supply.
   Heat pump installation and service instructions

2. Drain the system.

3. Remove front panels.
   Heat pump installation and service instructions

Removing the instantaneous heating water heater

Note
The high-limit safety cut-out can only be replaced together with the instantaneous heating water heater.

Preparing for installation

Installing the instantaneous heating water heater

Notes on steps 1 and 2:
Ensure the O-ring and flat gasket are seated correctly.

Note on step 3:
Bundle the cables below the instantaneous heating water heater so that they do not touch the base plate.

Commissioning

1. Please note
   If the heating circuit is not sufficiently filled with water, the instantaneous heating water heater will overheat. This can damage the instan- taneous heating water heater.
   Fill the heating system completely and vent.

2. Check for leaks.

3. Carry out a function check; see next chapter.

4. Close the heat pump in reverse order.
   Vitocal installation and serv-ice instructions

5. Start the heat pump.
   Vitocal installation and serv-ice instructions

Carrying out a function check

The function check ascertains whether the set heating output of the instantaneous heating water heater is available and whether the high limit safety cut-out responds.

Note
Read through all steps before carrying out the check.

Carrying out a check with excessively high flow temperature

1. Prevent DHW circulation in the secondary circuit via valve. The line between heat pump and onsite safety valve must remain open during this test.

2. Start the instantaneous heating water heater separately via the heat pump control unit.
   Service menu:

3. Hold down simultane-ously for approx. 4 s.

4. “Actuator test”.

5. “All actuators” set to “OFF”

6. “Inst.water. stage 1” set to “ON”

7. “Inst.water. stage 2” set to “ON”
   Note
   The secondary pump must not be switched on.

8. Measure the current through the instantaneous heating water heater:
   Measure the current using a clamp ammeter (current clamp) at every conductor (L1, L2, L3) of the power cable for the switching module. During heat-up, current is present; the current is interrupted if the high-limit safety cut- out responds.

9. Observe the electricity meter for the instantaneous heating water heater and switch OFF other consumers in the building if required.

Max. heating

output

| Current per con-

ductor

---|---
8.8 kW| approx. 13 A
5.8 kW| approx. 9 A
3 kW| approx. 4 A

Please note
If the instantaneous heating water heater overheats over a prolonged period, this may damage the appliance.
If the high limit safety cut-out does not respond, switch OFF the instantaneous heating water heater via the heat pump control unit.

Service menu:

1. Hold down simultaneously for approx. 4 s.
2. “Actuator test”.
3. “All actuators” set to “OFF”

Power supply

400 V/50 Hz

• A Switching module
• B Jumpers
• C Max. fuse rating 16 A

230 V/50 Hz

• A Switching module
• B Jumpers
• C Max. fuse rating 16 A

Lowering the temperature in the secondary circuit

1. Re-enable DHW circulation in the secondary circuit.

2. Switch ON the secondary pump separately via the heat pump control unit for approx. 60 s.
   Service menu:

3. Hold down simultaneously for approx. 4 s.

4. “Actuator test”.

5. “All actuators” set to “OFF”

6. “Secondary pump” set to “ON”

7. Isolate the system from the power supply.

Resetting the high limit safety cut-out

Press reset button A.
Note
The high-limit safety cut-out can only be reset if the flow temperature lies below 78 °C.

Fault analysis
If the instantaneous heating water heater is not heating (no current) or the high limit safety cut-out does not respond, this may have the following causes:

instantaneous heating wa- ter heater to switching module; check switching module power supply; see Vitocal installation

and service instructions.

Jumpers incorrectly set at the switching module| Check jumpers; see Vitocal installation and service instructions.
High limit safety cut-out faulty| Replace the high limit safety cut-out together with the instantaneous heating water heater.
Temperature sensor in high limit safety cut-out faulty or capilla-

ries kinked/broken

| Replace the high limit safety cut-out together with the instantaneous heating water heater.
Instantaneous heating water

heater faulty

| Replace the instantaneous heating water heater

together with the high limit safety cut-out.

Switching module for instanta- neous heating water heater

faulty

| Replace switching module for instantaneous heating water heater.

Viessmann Werke GmbH & Co. KG
D-35107 Allendorf
Telephone: +49 6452 70-0
Fax: +49 6452 70-2780
www.viessmann.com

Viessmann Limited
Hortonwood 30, Telford
Shropshire, TF1 7YP, GB
Telephone: +44 1952 675000
Fax: +44 1952 675040
E-mail: info-uk@viessmann.com

References

• Viessmann.com

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