Weeping radiator lockshield valve spindle

[Dave Baker]

In deep dudgeon today after my c*ck up with the leaking washing maching fill hose because I'm too stupid to realise there should have been a rubber washer at each end I'm determined to not let this new house go to shit like I the old one after I neglected things.

There's a small weep from the spindle of the lockshield valve on one of the rads. The plastic cap is such a tight fit though it's containing things and I've left it well alone for now. Google thinks I can lock the valve down, undo the spindle nut, wind a couple of turns of PTFE tape round the spindle, pack this in with a small screwdriver, apply a smear of silicone grease and refit the nut without having to drain the whole system down. That would be a major pain because the header tank in the loft is really hard to get to involving crawling through a maze of roof trusses and a chipboard wall with the tank at one end of the loft and the hatch at the other end 50 feet away.

There's also really good anti corrosion stuff in the system which is very slippery to the touch when I get some on my fingers when I bleed the rads and I don't want to waste that and have to replace it all.

Is Google correct about the spindle valve? I really don't want to have to replace the whole lockshield valve.

What might my "slippery to the touch" anti corrosion stuff be?

[harryagain]

Most TRVs have a tiny O ring seal on the shaft. (It has to be low friction in order to work propely) In days of yore a few had bellows. Finding a replacement O ring is the trick and usually the valve has to be dismantled and the spindle pulled out. Even if you replace it, quite often the shaft is scored and still leaks. Safest is to replace it. They are pretty cheap.

You can turn of the cold water stop tap and drain the tank and system down, into containers/buckets if neccessary to save the chemical. The trick will be getting it back in the system (nomally done by tipping it into the header tank).

[Dave Baker]

It's not a TRV. It's a lockshield valve like wot I said.

[Roger Mills]

Indeed. And yes, if it's the sort with a packable gland round the shaft, undoing the nut and sliding it up the shaft, adding some more packing and then replacing the nut will probably do the trick.

In the past, I've used hemp - or even string - but not PTFE tape. PTFE tape *may* work, but something which swells a bit when moisture is present would be better.

[DerbyBorn]

Roger Mills wrote in news:ce3ma9Ff6e4U1 @mid.individual.net:

Turn off the valve at the other end as well to isolate the radiator. Release any residual pressure with the bleed valve. You may get away with just tightnening the nut - but if it has already bottomed out then follow the advice about making a string of PTFE tape. Think about which way you wrap it so that refitting the nut doesn't unwrap it.

[Andrew Mawson]

MUCH better to replace the offending lock shield valve!

This is where my pipe freezer comes into it's own. Screw the TRV down, close the lock shield valve, release radiator pressure via bleed valve, freeze pipe leading to lock shield valve. Replace lock shield valve with a new good one (not all are!). If you are lucky no need to pull olive off pipe if fitting thread is same as old one.

(In all honesty you probably would get away closing ALL your rads, releasing system pressure at a suitable point, then undoing the offending lock shield with a wet & dry vac standing by to cope with anything that escapes)

Andrew

pst - want to hire a pipe freezer :)

[Scott M]

Where Dave is he just needs to turn the heat off and open the door for a while...

[John Rumm]

Yup it will normally work. PTFE string is better than tape in this case but tape works especially if you twist it into a string before you wind it round. Pack in a good ten turns or so if you can.

Fungal slime?

(any of the normal inhibitors I have used don't seem to change the feel of the water - although I suppose some of the antifreeze ones may)