hi, i have an alpha HE cb25 boiler and ive just had a new reciever fitted as it was faulty. Now when i have a shower the water runs hot, then cold, then hot then cold... repeatedly!!! heating works fine... how do i fix... some one help....i want a normal shower! ha :P

shane, November 2010

I have the same issue with the same boiler.
The heating is fine, the hot water from the tap or shower cycles hot and cold. I hear the boiler shut off when it turns cold no error lights then it fires back up with hot water again and then repeats over and over.
I have replaced the diaphragm, replaced the temperature sensors. Thinking of changing the dhw heater matrix or diverter valve.

Hammer it!, February 2012