Radiators warm when heating off - valve stuck maybe?

[hughjayteens]

Hi All,
I have an Ideal Mexico boiler which feeds my system via a Grndfos pump and then a couple of 2 port valves. When i turn the heating off at the stat and timer, but leave hot water on, the rads still get a little warm. Am I correct in guessing it is probably a sticky valve?

If so, would it be the one on the feed into the side of the Hot Water tank, or the other (which I assume feeds the rads?).

Also, the pump seems to be hot even when the heating is off - should it be working when I just have hot water select on the timer?

Thanks in advance.

Chris

 

[seco services]

the pump will work on both hw / heating.

it will be the valve that feeds the rads that is sticking if the rads get hot when off.
check to see if the pipes either side of the valve are hot, if they are the valve is letting by. maybe sticking or crund in the port restricting it to shut or the paddle in the bottom worn.

 

[hughjayteens]

Cheers for that - do I need to replace the valve or can I free it up somehow?

C

 

[Agile]

It depends on exactly why it is letting by.

For a start select heating about 10 times to see if that clears it. If not you will have to drain it and open to see whats wrong.

I replaced a fairly new one recently with a trainee and so investigated it in detail although that was only one problem and yours might be another.

The ball is expected to rotate and present new sealing surfaces to the brass port.

The ball was stiff with dirt deposits on the steel shaft. The ball had stopped rotating and was indented from always sealing at the same position. For fun, I cleaned and silicone greased the shaft and was able to free it up to rotate as easily as the new one.

Tony

 

[mikmik]

has the system always done this or have you just lately noticed it to do this .or have you definately found this has happened lately..the reason i ask is because if you only lately noticed this happening it might have been happening all along due to the return pipe fron the hot water and the central heating being common i.e ..only one return pipe from both systems may sometimes one pipe circulation i.e ..the heating system being slightly heated from the return from the d.h .water cylinder..