CH not switching off

[naeyis]

Could someone please help me with a problem which has just developed with my central heating around about the time I topped up the system pressure to approx 1.5 bar, although this may be just a coincidence.
My central heating stays on constantly even though I have the thermostat right down ( this seems OK as I can here it 'click off' ) and the controller is in the off position. The hot water system sees fine and is working normally via the controller. The boiler is a Vokera Mynute.
Many thanks in advance.

 

[godhelpus]

I have had this with my boiler running when timer off. Result was that a microswitch on a zone valve was sticking which back powers the boiler. Have a look at your zone valve for the central heating - they often have a small microswitch that makes once the valve is in position. I replaced my microswitch - cost £1.50 from Farnell.

 

[naeyis]

Thanks for the reply godhelpus but, after speaking to a plumber I know in the pub, I found out there was a frost stat associated with the boiler and right next to it hidden in a j/box. A wee tweek on this and voila problem solved.