Alpha C23 hot water fault

[Jambo123]

Hello people! Please could someone help solve this problem I'm having with my boiler. When I run hot water tap, the boiler fires up, but only delivers Luke warm water. I have noticed the radiators getting warm also, while running the hot water tap, even when I have the boiler set on hot water mode only. The water will get warmer as the heating gets hotter. Please help

 

[Agile]

Sounds like a diverter valve failure.

Until thats fixed you should get better hot water if you close one of the heat circuit isolating valves.

Tony

 

[Jambo123]

Thanks for the reply. This boiler doesn't have a diverted valve. I've tried a pcb as well to no avail. When I run the hot tap the pump runs as well

 

[ianmcd]

You are correct Jambo your boiler has a Bi Thermal heat exchanger sometimes called a twin pass and yes it does not have a diverter valve, change the thermistor not a big job and reasonably inexpensive

 

[Agile]

If no diverter valve then why is the pump running during DHW Ian?

 

[ianmcd]

If no diverter valve then why is the pump running during DHW Ian?

When the thermistor faults tony the pcb thinks the thermistor is in frost protection mode and causes the pump to run, its a common fault with that range