Right, here goes.
Equipment: Boiler W/B Greenstar, Timer Honeywell ST400C, Drayton wireless thermostat.
We have recently noticed that the heating has been going off a couple of hours into it's requested time slot and then coming on just before its no longer required, ie it's due to be on from 4.30pm to 10.30 pm and but it goes off about 6.45pm then comes back on at about 9.30pm.
I've checked the boiler, all is well, no fault code flashing. The thermostat calls correctly and the green llight on the receiver responds as it should. It's as if the timer is playing up.
Outside of this evening period the whole system (inc, hot water) runes as it should.
I've tried completely reseting the timer too but thats made no difference.
Faulty timer? Any advice would be great.