how do i isolate a leaking radiator?

rapunzel · Joined: 12 Apr 2006 Posts: 2 Location: United Kingdom

Hi. I have a radiator that has sprung a leak at the base. It is dripping quite badly. Unfortunately, my usual plumber has gone on holiday and I have no real diy experience. I have closed what I believe is the lockshield valve (removed the white cover and turned the spindle clockwise with pliers until it was tight). The other valve is a honeywell trv for which I do not have a decorator cap. I closed the trv down to zero expecting the flow to at least slow, but after several hours it still seems to be dripping at the same rate. I have read that trvs remain open for frost protection, but this seems unlikely as it is not that cold. Should this have worked? What else could I do? Should I try to get hold of a decorater's cap - if i can get one is it obvious how it goes on? Please help if you can, bit of a damsel in distress here.

JPC · Posted: Wed Apr 12, 2006 6:25 pm

the trv should be ok at zero. i learnt on this forum u can on some models place a penny between the trvhead and pin to push is further down and therefore it wont open no matter what temp...

all that is by the by. close both valves off as you have done. the rad is still full of water at this stage. u can place summit under the drip till it stops (depends on size of rad etc) or u can undo the rad valve and empty it that way..into a pan or paint tray etc ...opening the bleeding valve allows the water to come out quicker. this should take about 10 mins ?(size of rad dependant) and then the rad should be empty and no more water should come out ......as long as ur rad valves are closing properly

rapunzel · Joined: 12 Apr 2006 Posts: 2 Location: United Kingdom

Thanks JPC. To remove the trv head, is it just a case of undoing the collar at the bottom and pulling it off? The trv looks like this http://www.plumbworld.co.uk/776-2960. Cheers.

kevplumb · Posted: Wed Apr 12, 2006 7:28 pm

sure is

jobloggs · Posted: Wed Apr 12, 2006 10:31 pm

Fernox do a leak sealer. It has had mixed reviews on this forum but may be a cheap fix if leak is not too bad.

However leak usually due to corrosion so you need to look at flushing and adding inhibitor to limit any corrosion damage elsewhere.

JohnD · Posted: Wed Apr 12, 2006 10:54 pm

Good point Joe. Fernox LSX is the stuff, a sort of extra-fast setting rubber paste. It will stick to wet surfaces, provided there isn't pressure squirting the water out. It will also stick to your fingers until it wears off a week or two later.

Like Joe says, you probably have a rusty radiator which needs changing; LSX may get you out of trouble until you can have a new one fitted. Unfortunately all the other rads are probably rusty as well. ask your plumber about flushing and inhibiting to stop your new replacement rads going the same way.

P.S. on those TRVs, I believe that if you press the little button you can turn the head beyond its normal range. that might help you screw it down further.