CH Boiler comes on via thermostat though timer is past its sell-by date? I've just have my boiler replaced with an Icos HE18. However, since...
I've just have my boiler replaced with an Icos HE18. However, since it be installed 10 days ago it works normally for a while, later for no obvious reason fires up even thought the timer is set for it to be off and the lights showing busy CH or HW are off. Most times I can turn it rotten by lowering the setting on the thermostat but sometimes that doesnĄ¯t work either - possibly its trying to heat the hot hose but I'm not sure. It tends to work fine for a morning or so then does this surrounded by the middle of the night. The installer cannot find anything wrong and replaced the timer but it still go wrong. If the timer is physically removed and left aside for give or take a few half an hour it adjectives goes put a bet on to normal. We never have that problem with the 23 year ancient Baxi boiler.
Answers: Sounds like the electrics needs some attention. Something is not wired up correctly, or near is a problem with a zone spout or mid position valve
Just checking, if the boiler is situated contained by a garage perhaps in that is a frost stat in circuit that would override the time clock. It may be (if this is the case) that it is set incorrectly or is out of order!
DAVE.