Boiler fires up when heating off

[stevewright1988]

Hello. Wouldn’t if someone could help.

I have a boiler Downstairs in utility with a separate hot water cylinder upstairs in en-suite.

hot water is turned off at the controller, central heating is on at controller but thermostat is below room temperature. boiler is still firing up and running, 2-3 radiators close to the boiler are warm but rest of the house is off.
Is this due to a sticking diverter valve.?

kind regards and Thankyou for any advice.

 

[SJB060685]

2 port or 3 port? Could be the valve, could also be the stat

 

[stevewright1988]

2 port or 3 port? Could be the valve, could also be the stat

Thankyou for the reply. There is 2 valves. Both 2 ports I think. I have limited knowledge of this sorry.
I assume the stat is okay as it’s just a Honeywell analog stat. Does click on and off okay. When on all radiators warm up but when off they all cool down apart from a couple that are staying constantly warm.

have attached a photo of the airing cupboard where tank is.

 

[SimonG]

Do you have a frost stat on it with it being in the utility?

 

[stevewright1988]

Do you have a frost stat on it with it being in the utility?

No frost stat installed on it

 

[SJB060685]

Thankyou for the reply. There is 2 valves. Both 2 ports I think. I have limited knowledge of this sorry.
I assume the stat is okay as it’s just a Honeywell analog stat. Does click on and off okay. When on all radiators warm up but when off they all cool down apart from a couple that are staying constantly warm.

have attached a photo of the airing cupboard where tank is.

Yes you have 2 2 ports my friend, one for HW, the other CH. This is an electrical issue somewhere so advise you getting a competent guy/girl around. Firstly I'd be checking in the wiring centre to see if stat is actually shutting down, if it is I'd be checking if the end switch is sticking keeping a live to boiler.