Radiators randomly came on and wont turn off.

[j4g3d]

Hi guys,
Thermostat is in the OFF position but the boiler is on and the radiators are piping hot.

If i turn the hot water on the boilers light turns on for the RADS but lights up as it should for the HW. If i turn the HW off, the light for HW turns off, as it should but, the radiator light is ON again. Eeek.

Whats going on here? internal fault in the boiler?

 

[terryplumb]

Make and model of the boiler would be helpful.

 

[j4g3d]

Make and model of the boiler would be helpful.

It would, wouldn't it lol.
BAXI COMI 28 HE

Although googling that model shows one that appears to be different. Mine looks like this:

http://www.home-boilers.co.uk/Baxi-Duo-Tec-28.html

 

[ianmcd]

Post a pic of your thermostat so we can see what you have

 

[j4g3d]

Post a pic of your thermostat so we can see what you have

https://imgur.com/a/9jhtWlD
https://i.imgur.com/Mac2QuF.jpg

 

[muggles]

What happens if you move the slider on the programmer from "CONT" to "OFF"?

 

[picasso]

Might be Frost protection kicking in which means main thermistor fault, if you turn selector dial to summer mode and boiler stops then frost protection most likely fault.

 

[j4g3d]

What happens if you move the slider on the programmer from "CONT" to "OFF"?

If I do that then the hot water is back. Radiators aren't on BUT.. if i then turn the thermostat ON, the radiators still don't come on..

What do you think? Faulty thermostat? it doesn't actually feel right when i turn the dial, normally it clicks when you turn it on but now it just click like a button.. its odd, definitely doesn't feel right.

 

[j4g3d]

Might be Frost protection kicking in which means main thermistor fault, if you turn selector dial to summer mode and boiler stops then frost protection most likely fault.

Which ones summer mode bud? I normally keep it on CONT.

 

[muggles]

Yep, sounds like a faulty thermostat to me. Worth testing with a multimeter before replacing though

 

[j4g3d]

Thermostat replaced and all working again. Thanks