Cold towel rail

[BarkingMadBarking]

Hi, I've got a cold towel rail. This what I've done so far:

1) Closed all over radiators except towel rail and run heating until boiler nearly knocks off - and then turn boiler stat dpwn, but leave room stat up and pump running. Hot water should be circulating and shouldn't have problems with balancing. It's a traditional hot water cylinder system with 3 way valve.
2) Bled towel radiator. Bleed valve shows water and is located above flow inlet.
3) Tried all combinations of flow and return valves; both full anti clockwise; both full clockwise; one full anti+other clock.
4) With both full anti (I think this means they are open - like turning on a tap), the inlet valve gets warm but the radiator immediately above the valve is slow to warm up (or just cold).
5) I've noticed the valves don't seem to move far. The flow moves from 12 o'clock (full anti clockwise), to 9 (full clockwise - without passing 12). This doesn't seem far - compared to valves on other normal radiators. Also noted that the movement seemed to increase as I was preparing the photos.
6) The return valves moves from 12 to 2.

Any ideas what is wrong? I assume full clockwise means the valves are closed. I think the valves may be faulty / blocked? Perhaps I should take the rad off, to inspect the valves and perhaps open the flow whilst pump is running to check the flow/comfirm valve is working.

I've attached a picture of the valve. Can I undo nut B and look at the spindle mechanism?

Thanks in advance.

First two images are flow (full a/c, full c); second two return (full a/c; full c); last valve with "B" arrow pointing left.

1. Flow - full a-clockwise

• BarkingMadBarking
• 28 Oct 2012
• 1

2. Flow - full c/wise

• BarkingMadBarking
• 28 Oct 2012
• 1

3. Return - full a-c/w

• BarkingMadBarking
• 28 Oct 2012
• 1

4. Return - full c/w

• BarkingMadBarking
• 28 Oct 2012
• 1

5. Valve

• BarkingMadBarking
• 28 Oct 2012
• 1

 

[mcmoby69]

one of my customers had exactly same problem with those valves. i drained the system, stripped the valves cleaned them and reassembled.

worked fine after that.

 

[BarkingMadBarking]

one of my customers had exactly same problem with those valves. i drained the system, stripped the valves cleaned them and reassembled.

worked fine after that.

Thanks. I think it is a sticky valve because since the post I've managed to turn the inlet valve further a/cwise, from 12 to 9. To strip them down, once I have removed the valves, so I need to undo nuts A and B in my picture or just A?

5. Valve

• BarkingMadBarking
• 28 Oct 2012
• 1

 

[mcmoby69]

B will get the guts out of the valve. once thats out you will be able to see if there are any obvious problems.

 

[BarkingMadBarking]

Thanks.

And since this radiator is the highest one in the house, then if I drain this one, by loosening B, I should be able to unscrew B without disconnecting the body of the valve from the pipe or raditaor. Correct?

 

[mcmoby69]

yes, make sure you turn of the water supply to the CH either by tying up the ball valve in the loft or turning off the cold water main.