Alpha 240P - cycles on and off without demand

[idelone]

Hi All,
I have an Alpha 240P that randomly switches itself on at odd times during the day/night without any demand being called for. When turning on the tap it will ignite the boiler and heat the water for a while and then the flame will die down and the water runs cold. The diverter valve functions correctly making contact with both micro switches when operating in heat/ water modes, and was recently overhauled due to leaking from the body of the valve.
Any ideas anyone ?

 

[Agile]

Why dont you monitor the voltage on the call for heat terminal and see if a signal is being provided from a fault in your controls?

Tony