Honeywell CM67 thermostat and Ideal mini boiler

[snb]

you need to check that optimisation is disabled. On the cm67 they come with it enabled. setting 15op needs to be set to 0.

if not the unit will try achieve the desired temp by the time you have chosen ( can come onor switch off up 2 hours prior to time)

so you would end up with worst case senario the following



boiler comes on at 04.20 till 06.20
switches off at 06.20 till 15.30
switches on 15.30 until 18.00

 

[Cptkenny]

Thanks for your response - the problem is it not coming on, it does not go off - the radiators are scorching all the time when my boiler is set at 70 and my CM67 set to auto when it should be cooling them down but it doesn't

Think I will just have to keep the stat on manual and adjust the boiler as and when until i can afford an engineer.

Thanks again.

 

[shambolic]

There is frost protection built in to one of the thermisters if out of calibration it will keep boiler on (lights should flash to signify this)