Alpha CB50 boiler- Good one if you can fix this!

[minimarvel]

I have an Alpha CB50 boiler. Installed when moved in and with little use.


It keeps going into overtemp error with the red LED flashing. A reset will get it all working again, and it will continue to work for sometimes a month,but sometimes only an hour or even a minute....there is no pattern.

Changed the sensor......the same
Changed the main PCB.....the same
Removed the sensor to check not actually overheating....the same
checked and replaced wiring.....the same

Any suggestions would be welcome....even of a spiritual nature. I am fed up and out of ideas....there is nothing else to change or check?

 

[picasso]

Is it overheating ? what happened when you removed the sensor ? pump noisy or quiet.

 

[Boilerman2]

Sounds like the old intermittantly sticking pump syndrome to me doc!