Temp will not rise when thermostat dial is turned higher

[magick73]

No changes made whatsoever.
The rads are luke warm 10-15C max

 

[JohnD]

how about those photos?

I am particularly interested in the pump and electrically operated valve, since I think the water is not circulating properly

 

[D_Hailsham]

I am particularly interested in the pump and electrically operated valve, since I think the water is not circulating properly
If the pump was not working, the boiler would overheat and cut out.
If the pump was running too slow the same thing would happen and if set too fast the water would not reach temp. But the OP says he has not changed the pump speed.

If a motorized valve was not opening fully, you would get the same effect as a slow pump, i.e overheating.

I think it may be either a faulty boiler stat or the heat exchanger furred up.

 

[magick73]

Hi John - I have attached some pics which I hope my give clues...

Untitled

• magick73
• 10 Sep 2008
• 1

Untitled

• magick73
• 10 Sep 2008
• 1

Untitled

• magick73
• 10 Sep 2008
• 1

 

[JohnD]

feel the pipes going in and out of the pump and the electric valve, see which are hot.

feel the pipes going in and out of the hot water cylinder, see which are hot.

look at the cylinder and take a photo showing the thermostat which will be strapped to the side of it. Se what number it is set to, and of it clicks when you turn it up or down. The idea is that once the cylinder is hot enough, the hot water starts going round the radiators.