Leak on Rad return

[Wazz]

Hi All,

I took an upstairs radiator off so I could fit the new skirting board behind it, however, I have 2 issues from this. The first... the rad has a thermostatic valve and I turned it to the icikle, but now realise that this is not off!! (I have a brown patch on my loung ceiling) It started to dribble in the night.. how do I stop this? Can I cap it or remove the thermostat?

Second... During this removal and refit the joint on the return copper pipe must have been moved and also started to dribble. I gave the nut an extra quater of a turn but this hasnt solved it and I need to change the olive. but how.. If I turned off the boiler and let some water out so the pressure drops (combi boiler system) and close the valves on the radiator in question, could I then just undo the return off the rad and fix it.. Would I get much water out of the return pipe? Or is there an easier solution?

Thanks

 

[ChrisR]

REmove trv head (with rad ON), insert a small disc like a 5p coin, and replace head.
If rad is off, buy some caps for the rad union from a plumber's merchant, or drape hot towel over trv head!

To change a valve in a sealed system, if you close the auto air vent in the boiler, and let the pressure off at a drain cock, you shouldn't lose any water with only one end open. Wrap ptfe tape round the olive if you're going to reuse it.

 

[Slugbabydotcom]

Remove trv head (with rad ON) , insert a small disc like a 5p coin, and replace head.

He means with heating turned off and rad connected in position but TRV set to max which is usually #5

Good tip there Chris .... Never thought of that one.

It has spawned another idea. If you have difficulty getting the 5p or whatever in place under the TRV head, a tiny blob of blu tack could be handy

Can I cap it or remove the thermostat?

Cap it yes........ 1/2" BSP cap ends unless you have the much rarer 3/4" valves
Remove the stat and the water will come out of the valve. theres a pin underneath that needs to be kept pushed down to keep the valve closed.

Assuming you have 1/2" valves you could temporarily fit a bit of copper between the two valves if the distance isn't too great OR a bit of copper and an olive sticking out could have a stop end on it if you cant get hold of a cap end.

With rad OFF the wall open the valve and empty water from the system into a bowl. Then work on the valve as Chris says. Turning flow and return valves off under the combi is usually easier than closing off auto air vents for many combi's

Keep a carrot handy as an emergency plug if you are worried.

With the rad on the wall you may still be able to drain off the excess pressure at the rad if you can get enough play on the pipe. Close off the valve at opposite end to the valve you are working on. Most the time I get away with loosening the nut under the leaking valve wrapping a load of PTFE tape round and re-doing the nut.
If it gives you lots of grief ie wont seal don't rule out the chance of a hairline crack on the fitting or the nut.
If the olive and the end of the pipe is all chewed up by overtightening you may have to cut off the bad bit of pipe. In a really bad case you may have to renew some of the pipe.

 

[Wazz]

Thanks for all your help, I have sorted that little dribble out... However, I have taken off and re fitted two more rads today so I can get skirting behind them and I have encountered the same problem. the cause of this can only be when im undoing the nut between the valve and the rad that im letting the valve move on the coper pipe. Im trying to brace the valves as I crack the nut and they barely move, yet this seems enough to cause it to leak... is this normal? Is there a technique to this?

Also, I have a slight leak from the trv union nut(right terminology?) but I cant tighten the nut anymore... is it ok/normal to wrap these in ptfe tape? I only ask as I have never seen it done.

Thanks in advance,
Wazz

 

[Wazz]

As no answers does this mean that it was a simple/stupid question?
I am going to fix these tomorrow, anyone any advice?

on the plus side, the plumber came round and fitted a drain cock for me... this also leaks.... so it even happens to the pro's, which makes me feel better!

 

[Slugbabydotcom]

Scraping the brass fittings on a concrete floor as you move the rad about often knacks up the rad valve fittings. PTFE tape is one way of remaking the joint. Beware a faulty fitting which may have a hairline crack in it. If you have logically sealed everything thats likely to leak then its wise to recall that dodgy parts do exist

To the action of turning the nut you need an equal and opposite reaction on the valve so that it does spin. I tried explaining that to Albert Einstein but you know what hamsters are like, they just don't listen!