Biasi M90E.24S CH temperature problem

[gregsy]

DHW is working perfectly but the central heating wasnt fireing, but I made a bit of progress today, I unplugged the central heating thermistor and and the ch fired up for about 20-30 seconds today then it stopped, so I plugged the thermistor back in and it fired up again for around 20 -30 seconds. So I swapped the thermistor over but it carried on exactly the same with the changed thermistor i.e. plug in 20 seconds of fireing then stops then ounplugged 20 seconds of fireing etc etc

The strainge thing is when the temperature gets up to about 40 degrees on the guage it seems to stop fireing completely even when I plug and unplug the CH thermistor. So I plugged in a thermistor whilst it was off of the system and it did the 30 second fire and switch off again.

The gas cut out light doesnt trigger at all, so I asume this signifies its not the safety temperature probe.

Any ideas?

 

[metaldust9]

yes get gas safe person out before you fry yourself as you will change loads of stuff and be no better of as everything is linked to each other