S
samg
I have a Worcester Bosch greenstar boiler,7 years old,with a mechanical m10 programmer and Honeywell thermostat,the problem is that the hot water is working fine but the heating which is always switched to the on position on the programmer and controlled by the thermostat is not coming on when required,but it will randomly come on in the evening always around 6,as if its on timer,which it isn't,we have changed the thermostat but that didn't make any difference,I didn't know if the programmer could be faulty and reading as if it is on timer when its not,any advise would be appreciated