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I have the aforesaid boiler with a VR65 control centre and VRT 392f wireless thermostat which is set to two-point control.
The boiler's fault memory is full of F.72 (NTC fault) although the boiler appears to be working normally. I asked my heating engineer to change both NTC sensors as a fairly cheap initial attempt to fix it but it didn't.
So I hooked up my ebus monitor and found the modulation was looking very unstable:
I have set d.0 to 10kW which is 55% modulation. There is an initial spike as the flame is established then it drops down to 55%, but after a while it starts to oscillate.
Has anyone else come across this? Is it an indication of a faulty control board?
Mike
The boiler's fault memory is full of F.72 (NTC fault) although the boiler appears to be working normally. I asked my heating engineer to change both NTC sensors as a fairly cheap initial attempt to fix it but it didn't.
So I hooked up my ebus monitor and found the modulation was looking very unstable:
I have set d.0 to 10kW which is 55% modulation. There is an initial spike as the flame is established then it drops down to 55%, but after a while it starts to oscillate.
Has anyone else come across this? Is it an indication of a faulty control board?
Mike