Ferroli FER Falcon Boiler CH problem

Hi

After searching on here and elsewhere I have come to a dead end fault finding my boiler.

It is an FER Falcon approx 3 1/2 years old.

Yesterday there was a powercut and after that the CH stopped working on this boiler. The DHW works perfectly so I know there is nothing fundamentally wrong with the boiler or pcb.

I have replaced the external thermostat link to eliminate that problem.

I have swapped the CH and DHW thermistors which made no difference. Oddly, unplugging the CH thermistor starts the CH working (CH pump, fan and burner) for about 10-15 seconds after which it goes back to CH standby (blinking CH lamp). It then does nothing unless you unplug the CH thermistor again. Both relays are clicking healthily and the pump and fan both run.

What do I check next?

Many thanks

Ian

WHat does the manual say?

Manual says suspect clock or external thermostat.

Thermostat connection is temporarily hard linked. How do I test/eliminate the internal clock?

The manual also talks about status led's on the PCB which are not present on mine.

Thanks

Ian

Whoo Hoo!

Problem identified. Problem caused by faulty boiler timeclock relay. Problem temporarily solved by hardlinking the relay connectors together.

Thanks to ChrisR for pointing out what was staring me in the face. My missus will be pleased!

Ian