Troubleshooting
23
Greenstar – 6721852556 (2022/11)
▶ Vent water circuits sufficiently.
Fig. 47 Flow limiter and flow turbine (flow rate 35 kW: 14 l/min,
bottom pink / 50 kW: 21 l/min, bottom red)
Control unit
DANGER
Risk to life from electric current!
▶ Prior to all electrical installation work, isolate all poles of the power
supply and secure against unintentional reconnection.
▶ Pull control unit [1] out of the insulation and hang on the retention
bracket of the heat exchanger [2] by the hook on the rear.
▶ Release locking devices [4, 6] with a thin bladed screwdriver.
▶ Open the cover [3].
▶ Release the locking devices [5] to remove the cover.
Fig. 48 control unit
▶ Unplug connections from the module.
▶ Remove cable and strain reliefs.
Fig. 49 control unit - unplug connections and release strain reliefs
11
Troubleshooting
11.1
Central Heating trouble shooting guide
6720808926-36.1Wo
1
5
4
3
7
6
2
3
8
2
6720808926-37.1Wo
1
2
3
4
5
6
6
6
6720808926-53.1W
o
Problem
Possible cause
Possibly solution/check
No heat output from
HIU
Air in the heating system
▶ Vent the heating system fully at the radiator manual air vents.
▶ Vent the HIU fully at the manual air vents. Ensure system pressure is between 1 - 2 bar.
Central Heating pump faulty
▶ Check that there is power to the pump
section 7.1 for instructions on venting the
appliance.
▶ Replace pump if necessary.
Pump setting set too low
▶ Adjust pump to correct setting.
District Heating strainer blocked
▶ Clean strainer
Faulty Central Heating flow sensor
▶ Replace sensor
Faulty Central Heating return sensor ▶ Replace sensor
HIU room controller incorrectly set
or faulty
▶ Ensure that the flow temperature set-point is set correctly on the HIU room controller.
section 7.2.
▶ Replace room controller if necessary.
