Water too hot!

[OllyJC]

Recently I noticed that our hot water was getting far too hot and that the boiler was continuing to heat this after the programmer indicated that the heating and hot water were off. The pump continued to run. The continuous heating and pump running was fixed by fitting a new two-way valve (although the plumber who advised me how to connect the wires seemed a bit unsure). Anyway, whilst this seems to have fixed the pump/boiler continuous running issue, the water is still getting too hot.

I have fitted a new cylinder thermostat and turned this down to 40% and this has made no difference.

Is it possible that the two way valve has not been wired correctly and that this is causing the problem.

(The immersion heater is not on by the way!)

Any ideas?

 

[seco services]

if the pump/boiler are not running where is the hot water coming from?

 

[OllyJC]

The pump and boiler are running - but as it should, only when the programmer is set for the heating and hot water to come on. The problem before the new valve was fitted was that the boiler and pump continued even when the programmer showed the heating and water as off.

 

[seco services]

so all works ok but water is still to hot.

if the hw on at programmer and cyl stat is calling does turning the cyl stat down shut boiler down or does boiler keep running ?

 

[JohnD]

I gather you have an electrically-operated valve to divert the heat to/from the cylinder?

Feel the pipes and see if it is staying open when it should be shut.

That might be a wiring fault (but old, worn ones sometimes leak)

A photo of the valves and pipes may help.

 

[OllyJC]

I'll need to check when I get home, but I'm pretty sure that turning down the thermostat on the cylinder does not stop the boiler from running.

I suspect that the new valve is wired up incorrectly.

 

[seco services]

let us know if it don't its not wired into valve correct.

 

[gavinda]

the valve is obviously letting by with heating demand. show us the valve and you may get away just changing the guts on it rather than a bung job body change

 

[OllyJC]

After a bit of head scratching and trial and error, I have fixed the problem!

As suspected, the new valve was wired to the board incorrectly. The grey and orange wires have been swapped over and the problem is solved.