Ocean/Alpha 500E combi boiler problems

georgeedward

We have an Ocean/Alpha 500E combi boiler. I don't know how old it is: we've been in our house for nearly four years. It's run pretty well but in December the times at which the c/h came on and off started to change when it was at the "timed" setting and one day the c/h wouldn't come on at all if you switched it to the 24 hours setting. It eventually came on and has been working on the "timed" settings (but not at the times shown on the clock). An emergency plumber looked at it and said it was likely to be the circuit board. He didn't know if these were still availabe and (not surprisingly) suggested a new boiler at a cost of about £3,500.

The reason I'm posting now is that the c/h has recently been working only if you turn the thermostat on the boiler for the h/w down low and last night wouldn't come on whatever we did to the controls (set in on timed and then 24 hours). Does anyone know what is likely to be causing all this? Am I likely to be looking at a new boiler and if so, what would members recommend?

Thanks in advance for any help.