65
9.2 Other faults
9.2.1 No heat (central heating)
Possible causes Analysis Solution
The power LED is not shown. Yes
↓ No
Check the power supply.
Check the fuse; see Electrical schematic §11.1 .
The right display shows a line (
–).
The boiler is o.
Yes
↓ No
Switch on the boiler by touching just above the power LED and
holding this for 2 seconds
Room thermostat / weather-
dependent control is not connected
or is defective.
Yes
↓ No
Check the wiring.
Check OpenTherm, On/O connection of the boiler, or the
connection between the central heating boiler and the
OpenTherm room thermostat. Replace the thermostat.
Replace the weather-dependent control.
No electricity (24V). Yes Replace defective automatic. Check the wiring according to the
schematic.
Check Connector X13.
9.2.2 Central heating does not reach the correct temperature
Possible causes Analysis Solution
Water pressure in the system is too
low.
Yes
↓ No
Top o the system; see §7.2.1.
Room thermostat is not in order.
Yes
↓ No
Check the setting and adjust it if necessary.
Temperature is set too low. Yes
↓ No
Increase the central heating temperature; see central heating
demand. If an outdoor sensor is present:
Check the outdoor sensor for short circuiting: cancel this.
No flow in the system. Yes
↓ No
Check the T (±20°C) between central heating supply and
return. Ensure a correct flow in the system.
The boiler capacity is not correctly
set.
Yes
↓ No
Adjust the boiler capacity. See §8.3 and §8.6.
No heat transfer due to
contamination in the central heating
boiler/system.
Yes
↓ No
Flush the central heating boiler/system from the central heating
side.
Flue and/or air supply duct is blocked. Yes Check and (if necessary) clean the flue and the air supply duct.
9.2.3 Central heating system remains too warm
Possible causes Analysis Solution
Room thermostat / weather-
dependent control is defective or has
a short circuit.
Yes
↓ No
Check the wiring.
Check OpenTherm, On/O connection of the boiler, or the
connection between the central heating boiler and the RF
room thermostat. Replace the thermostat.
Replace the weather-dependent control.
There is thermo-siphon in the central
heating circuit.
Yes
Place a check valve (in the case of thermo-siphon) or a two-way
valve (if there is a second pump in the central heating circuit).
To Next Page
Loading...
