Central heating continued when switched off

[DIY67]

I have one of those horrible little Flomasta remote thermos controller boxes with the tiny spongey buttons. It's very complex to program so I only have it set on manual on/off. I have just ran the heating for a few mins and turned the box off which shows nothing on the led display. The heating continued to run which has never happened before. The only way to stop it was to turn the box on and off again.

Can anyone please tell me why it would fail to turn off the boiler when off ?

 

[Jurassicspark]

How long did the boiler remain on for? Could have been pump overrun.
It can be that your thermostat needs a clean from the inside, oil and debris may have gone inside the buttons and its preventing it from making a good connection.

 

[45yearsagasman]

Please describe your boiler and system type to get a more accurate replay. 9 times out of 10 its an external control of some type that is sticking and causing the boiler/pump etc to continue.

 

[ericmark]

The V3 micro switches inside motorised valves seem to be prone to sticking in. Unfortunately can't really change micro switch, need to change whole head, but I would say that is most likely the problem, but still only a guess.

 

[DIY67]

It just kept going and the display on the boiler showed the radiator blinking indicating it was on. The flomasta was completely turned off, with nothing showing on the display so it was definitely off. The boiler was serviced only last month with no issues.

It's a Glowworm Ultimate 30c

 

[Jurassicspark]

Yeah if the fault persists ill go for the motorised valve.

Do you have test equipment?

 

[DIY67]

Only a multimeter. And I can't open the boiler as not qualified.

 

[Jurassicspark]

Yeah its better to call a gas safe engineer in.