I have an Ideal H18 boiler which is about 18 months old. It’s controlled by a Hive thermostat. Recently the central heating has been coming on with no demand from the thermostat. After a while, it will turn itself off. im pretty sure it’s not the thermostat as you can hear the micro switches when they turn on and that doesn’t happen. If I power down the whole system for 20 mins or so it seems ok for a while, sometimes days at a time, but eventually turns itself on again. The boiler has an on/off knob and if I turn it to off(so the boiler still has power) I’ve noticed that the central heating pump continues to run. The boiler is under warranty still but nothing else is - the pump is about 20 years old. Is my problem likely to be with the boiler itself or another part of my system?