Ideal combi nf 80 OH cuts out.

[Carlc]

Just bought my 1st house, after settling in noted boiler behaving badly.
HW ok. but CH keeps going til OH switch closes boiler down. Resets after several minutes. No manuals etc left by previous owner.

Can anyone help please?

 

[ChrisR]

Can't identify boiler but it sounds like the HW switch is stuck open. Might respond to a prod if you can find it.

Guessing:-
Drop boiler cover and look for a microswitch on the end of a complicated looking brass assembly(diverter valve). Part of it (DV)will be about 3 " diameter.
Look for a pin on assembly's axis which moves when the tap is turned on, to operate switch. Pin or switch stuck. Wet?
Turn power off while you're doing it, pin will still operate.

 

[Agile]

Sounds like the FF 80.

This is a savio/Biasi 24s as far as the main components are concerned although a different fan and PCB are used.

It sounds to me as if either;-

1. The CH NTC is open circuit.

2. The PCB is not controling the temperature, see if it modulates down when the temp control is reduced.

3. The o/h stat has been reset too many times and is tripping at the normal CH temperature. Should be about 110*C to trip.

Tony Glazier