Inspection and service
21
Greenstar – 6721852556 (2022/11)
▶ Unplug the connecting lead [2] from the control valve [1].
▶ Undo screw fittings [3] and remove control valve.
▶ Install new parts.
▶ Purge the system correctly and check tightness.
▶ Vent water circuits sufficiently.
Fig. 41 Control valves
Heating system circulation pump
WARNING
Risk to life from electric shock!
Touching live electrical parts can cause an electric shock.
▶ Before working on electrical parts, disconnect all phases of the
power supply (fuse/circuit breaker) and lock the isolator switch to
prevent unintentional reconnection.
▶ Drain the HIU completely.
▶ Unplug connecting lead from the heating pump [1]. Use a
screwdriver if required.
▶ Undo screw fittings [2) remove heating pump [1].
▶ Install new gaskets if required.
▶ Purge the system correctly and check tightness.
▶ Vent water circuits sufficiently.
Fig. 42 Heating system circulation pump
NTC-WW sensor and thermal overload protection (accessory)
▶ Drain DHW circuit completely.
▶ To replace the sensor: unplug the connecting lead from the sensor
[1].
▶ Remove the retaining spring [3] and pull off the sensor.
WARNING
Risk of scalding
The thermal overload protection only works if it is correctly installed.
▶ Install the thermal overload protection so the arrow on the appliance
points in the flow direction.
▶ To replace the thermal overload protection: undo the screw fittings
[2] and remove the thermal overload protection.
▶ Purge the system correctly and check tightness.
▶ Vent water circuits sufficiently.
Fig. 43 DHW temperature sensor and thermal overload protection
Thermal bypass (accessory)
▶ Drain the HIU completely.
▶ Remove spring clip [2].
▶ Undo screw fittings [1] and remove bypass [3].
▶ Install new part.
▶ Purge the system correctly and check tightness.
▶ Vent water circuits sufficiently.
Fig. 44 Thermal bypass
6720808926-29.1Wo
3
3
1
2
1
2
0010018683-01
0010018683-01
6720808926-32.3W
o
2
4
3
1
1
6720808926-34.2W
o
2
3
1
