I have a 2 year old Ideal Isar Combi Boiler which is on a Drayton Digistat RF3 Wireless System.
My probem is that when the radiators are due to turn off, the upstairs radiators are staying hot. This has only started happening within the last few months, I have changed the batteries in the Digistat control and also reset the boiler. A heating engineer has checked the boiler and says it is 'running as sweet as a nut'.
At the moment we are having to turn the boiler off at night.
Sounds to me like your zone or diverter valve is faulty and allowing the water to flow pass the valve when it should be off, the cause of this is probably dirt on the valve seating stopping it sealing shut. the only way of curing this is to replace the insides of the valve if possible or just by replacing the whole valve.
hi there when the rads are still hot are you getting a "C" on the display panel on the boiler?? if so the room stat is telling the boiler is fire,if the boiler is on "D" for dhw or "0" for standby mode and the rads are still getting hot then it is a problem with the divertor valve in the boiler.