cold rad

[kjam]

3 months ago i had a towel rad fitted in bathroom, has been working fine but slowly getting colder and colder. It started off from the top but now the whole thing is cold, i have \\\"bled\\\" it many times but still no luck. all the other rads throughout the house are hot bar this one
It seems like a common problem. what should i do?

 

[Bahco]

Turn all other rads off , bleed this one.
Make sure valves are open

 

[kjam]

still not working, any other ideas.

 

[JerryD]

Did you bleed it with the heating turned off (i.e. pump off)?

If so, did any air come out of the bleed valve?

If so, did any water then come out of the bleed valve?

Try bleeding it with one valve shut, does it still bleed?

Try bleeding it with the other valve now shut and the first valve open, does it still bleed?

Since installing this towel rail, have any other rads in the house been turned on that were previously turned off?

 

[kjam]

i have bled it with boiler on/off. no air comes out now it did before ..just clear cold water comes out of the bleed valve now.

i have just tunred of all the other rads and left the cold one on... to see if that works.

it only has a thermo valve on one side, and a cover on the other one.. do i need to take the cover off and turn it on/off..

all rads have always been on.

 

[JerryD]

well if water is coming out that's a start! However if one of the vales is blocked (or off) then you'll still get water out but no circulation hence me suggesting trying bleeding with alternate valves open/shut. This will determine if one of the two valves is blocked.

Take the head off the trv and ensure that the pin in the valve springs up (try pushing it back down with a coin or something). The pin uppermost means that valve should be open.

Take the cap off the other valve (lockshield valve) and spanner it shut (count the number of turns needed so you can later return it to its original setting for balancing reasons)

You now have the trv full open and the lockshield fully shut. Can you now bleed it and still get water, let plenty out as the bulge effect of the rad will push some water out of the towel rail even with both valves shut. If you're happy that there is plenty of 'flow' from the trv side on the system then you need to re-fit the trv head, turn the trv fully off, fully open the lockshield and bleed again. You should get identical results, i.e. plenty of water out of the bleed valve.

If all is ok, leave the lockshield fully open and also fully open the trv. This now makes the towel rail 'fully open' to the system with minimal restriction. Now manually turn off all your other rads but leave the central heating running (make sure it is running by turning up the room stat to max - this ensures the pump is running)

The towel rail now should get hot!

If it doesn't then you may have a blockage somewhere or a Bahco says below, trv faulty.

 

[Bahco]

Sounds like your Trv is playing up.
Take the head off and tap pin gently to see if it frees it off.
You will know if it is the Trv playing up if you turn all other rads off and find that the supply and ret pipes feeding it are hot

 

[kjam]

cheers buddy,

will try again in the morning sounds abit complex as never done owt like it before.