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8.3 Burner resonates
Possible causes
8.4 No heating (CH)
1. Check the wiring.
2. Replace the thermostat.
3. Replace the weather-dependent control.
Room thermostat/weather-dependent
control not closed or faulty.
1. Check the voltage.
2. Check the connector x4.
3. Replace defective pump.
4. Replace defective controller.
1. Replace sensor S1 or S2.
See Fault code display: 1 or 2.
1. See Burner does not ignite. Burner does not ignite.
Yes
No
Burner does not operate on CH: -
Sensor S1 or S2 faulty.
Yes
Pump does not run.
Yes
No
Yes
1. Check the wiring according to the
diagram.
2. Check the connector x4.
3. Replace defective controller
No voltage (24 V).
Yes
No
No
Possible causes Remedies
1. The house gas meter may be faulty. Inlet pressure too low.
Yes
Contact the gas company.
No
1. Check the adjustment,
see Gas-air control.
Gas-air mixture not adjusted properly.
Yes
1. Check the flue gases and air supply. Re-circulation of the flue gases.
Yes
No
Remedies
