Why are my radiators Hot?

[topgazza]

As its 27 degrees outside this is a bit uncomfortable.

I have an unvented pressurised system and the central heating is turned off. Its only a couple of rads, downstairs oddly but it is odd. They are not boiling but quite hot.

Is it some kind of heat transfer ?

 

[Al-Glasgow]

Have you been using any hot water recently ?

Al

 

[chrishutt]

what boiler do you have?

 

[topgazza]

Wow, that was quick.

1. yes bath for my daughter and washing up

3. Potterton Profile about 14 years old but still passes BG yearly check for saftey....

 

[chrishutt]

Suspect a stuck microswitch on a motorised valve. Do you have a 3 port motorised valve, or 2 x 2 ports?

 

[Al-Glasgow]

Im not familiar with your boiler, maybe Chris can shade some light.

My assumption would be your mid-position valve is leaking across to CH, or an internal boiler component like the heat exchanger.

Alan

 

[topgazza]

Thanks guys.

It looks like theres 2 x2 valves near the Ariston unvented tank. One is on the side coming ouit of the tank. The pipe goes downstairs but has an end as well with a bleed nipple and the other appears to be in the circuit with the pump and the loop into the central heating pipes. The one on the CH pipes has returns to home position if I push the lever, theres resisitence as well. The other one has no resistence and can be pushed back and forward.

Any of this making sense?

Boiler is a Potterton Profile 50...

 

[ollski]

yes the ch valve dont shut completely. Turn everything off and then when cold fire up your hot water, if the other side of the valve gets hot (a few inches on) then its passing.

 

[topgazza]

Ok. Just double checked. Picture shows the bottom (to CH valve) and the one at the top has no resitance. The pipe from the bottom valve goes in the CH and is hot on the pump side but not quite as hot on the other side . Could this be the leak you are talking about causing HW to circulate by convection through the rads? Again the bottom valve has resistance and does appear to return to its "home" position.


If you suspect a faulty valve I can use my BG House policy and get them out to fix it. Although I have changed valves before and it is easy I might as well get my moneys worth....

 

[ollski]

It's not really anything to do with the resistance on the arm but the fact that the ball in the valve which shuts the pipe off has swollen, or scale has built up in the valve so as to not allow a complete seal. Yes Bg do it on the cover, might even turn it round to make it a bit more accessible.

 

[topgazza]

Cheers guys, I'll get onto them today.

 

[wilhelm]

kevplumb..... have you been holding soldering lessons again?

thought so..

 

[topgazza]

Are you implying he is the Stevie Wonder of plumbing, only without the Motown recording contract ?

 

[wilhelm]

errrrr nothing that deep.

i was merely taking the p£ss

 

[topgazza]

That'd do it...