I have tracked down the problem the thermostat is conectted via a radio link to a Danfoss RX1 . This was the problem, I had a electronics technician look at it at work . The problem being the breakdown of the supply of 24 volts to the internal electronics. It does not use a transformer but...
I think i am getting closer to the problem after looking at http://www.newtonnet.co.uk/house/boiler/servicemanual.pdf
but I am uncertain what it is asking, does the thermostat latch as a simple switch with the voltage coming from the boiler. Or does the boiler expect 230 volts to be inputted...
No its the same thermostat. Its a radio one (Danfoss) it seems to latch correctly and its been used for three years prevoisly on a RavenHeat boiler but now for 2 years 5 months on the Worcester
My boiler has started playing up, this has become apparent since it summer switch off of the central heating system. The problem is the boiler only works up on till its first temperature control. If it has not been worked overnight or when we come home the when the boiler is cold it works fine...