Plumbers Challenge!!

simonhgreen

Hi Guys

I have a radiator which recently started leaking from the spindle on the valve.

Thanks to some advice from this site I tried to tighten the nut, but the leak still persists.

The weird thing is that when the heating is on and the valve is hot it doesn't leak, and when it goes off and the valve cools the leak starts. Adjusting the valve spindle just increases or decreases the flow but doesn't stop it.

I have an engineer coming tomorrow to service the boiler & have a look at the rad.

I was after a bit of advice to ensure the engineer doesn't perhaps "embellish" the cause of the leak, with the consequent hike in cost.

The logical thing that occurs to me is that there is some sort of washer in the valve that maybe has become warped/split, causing the leak, but expands when hot, sealing the leak/split.

I was after some feedback from anyone with more knowledge than me (i.e. everyone!).

Does this sound like a likely scenario, or are there other possibilities?

Any advice would be much appreciated.

Thanks

jobbingmusician

OH says yes, it's the valve. It doesn't leak when hot cos the metal expands.

Depending on the age of yr rad, it can be packed with hemp or the valve may need replacing.

HTH! :rudolf:

grumpyoldgit_2

Hi

I think you are right - this may help - taken from HERE:

LSV with cover on LSV with cover removed

[font=Verdana,Tahoma,Arial,Helvetica,sans-serif][size=-1][/size][/font]
[font=Verdana,Tahoma,Arial,Helvetica,sans-serif][size=+2]Q:How do I stop a leaking radiator valve dripping?[/size][/font]

[font=Verdana,Tahoma,Arial,Helvetica,sans-serif][size=-1]The stem, that the shut-off knob pushes on to, tends to have a few drips come out of the top, as the internal washer moves from the top to the bottom of the valve seat. This is usually nothing to worry about. If it does continue after a short while, then tighten the small nut on the valve spindle SLIGHTLY (it will only move a small amount anyway, but if the seepage does NOT subside, it is best to replace the valve). [/size][/font]

Cheers
GoG

moneysavingplumber

The type of rad valve illustrated above is the cheaper variety which are not 're-packable', so the nut around the spindle shouldn't be tightened or attempted to be tightened (on another point, there shouldn't be any PTFE tape around the union threads either, the joint is made between the two faces of the unions and there should just be a little jointing compound on the faces only). The leaking will usually subside if the valve is fully open, but will resume if you make any adjustment, but it will not get better on its own. I'm actually replacing rad valves throughout someone's house next week for this very problem, he had a swimming pool in his living room on Boxing day after trying to turn a rad down.

I only use Myson Matchmate valves which are good quality, reasonably priced, and have a re-packable gland so this would not become a major problem. It is possible on a gravity fed system to change a single rad valve without draining the whole system using a bung kit in the f & e tank, but you have to know what you are doing, but using this method it is only thirty minutes work and won't require you to re-treat the system afterwards.

Most modern quality valves now use a nut and olive as opposed to a union joint and you would need to change the tail as well, requiring the correct tools for the job.

grumpyoldgit_2

Sorry to pinch this thread for a while but can msp elaborate further on this point:
"It is possible on a gravity fed system to change a single rad valve without draining the whole system using a bung kit in the f & e tank, but you have to know what you are doing, but using this method it is only thirty minutes work and won't require you to re-treat the system afterwards."
As I want to put TRV's on some more of my rads but have put it off thinking I would have to drain down whole system - sounds like this may be the answer if you can add a bit more to the how?
Cheers
GoG

alanobrien

grumpyoldgit wrote:

Sorry to pinch this thread for a while but can msp elaborate further on this point:
"It is possible on a gravity fed system to change a single rad valve without draining the whole system using a bung kit in the f & e tank, but you have to know what you are doing, but using this method it is only thirty minutes work and won't require you to re-treat the system afterwards."
As I want to put TRV's on some more of my rads but have put it off thinking I would have to drain down whole system - sounds like this may be the answer if you can add a bit more to the how?
Cheers
GoG

Its the drain easy kit link below to the instructions on how to use it.

You put one bung in your vent the other in the header tank and it creates a vacuum stopping the water from
draining out of the system

Very simple and reliable for unpressurised systems only !


http://www.invensyscontrolseurope.com/lwwcm/connect/Invensys+Controls+Europe/Home/Products+%26+Services/Product+Selection+Tool/Drayton/Ancillaries+%26+Spares/Drain+Easy+Kit

grumpyoldgit_2

alanobrien wrote:

Its the drain easy kit link below to the instructions on how to use it.

You put one bung in your vent the other in the header tank and it creates a vacuum stopping the water from
draining out of the system

Very simple and reliable for unpressurised systems only !


http://www.invensyscontrolseurope.com/lwwcm/connect/Invensys+Controls+Europe/Home/Products+%26+Services/Product+Selection+Tool/Drayton/Ancillaries+%26+Spares/Drain+Easy+Kit

BRILLIANT - Cheers Alan
GoG

plumb1_2

grumpyoldgit wrote:

LSV with cover on LSV with cover removed

[font=Verdana,Tahoma,Arial,Helvetica,sans-serif][size=-1][/size][/font]
[font=Verdana,Tahoma,Arial,Helvetica,sans-serif][size=+2]Q:How do I stop a leaking radiator valve dripping?[/size][/font]

If you ever see a plumber installing a Rad valve, as above pics, throw him/her out of your house, it clearly the work of either a DIYer or cowboy chancer.
As MSP has stated, use only jointing compound on the face's, only need to use ptfe on the Valve tail (part you thread into the radiator)
Rant over.

The leaking valve could also be a Belmont type(large grey top) valve with O rings, which will just need repalcaing,and no amount of ptfe tape will stop it from leaking.
Rad valves tend to leak, if you have converted your system to a combi(pressurized) higher working pressure.

Best course of action is to change the valve, and also check all the valves on your system,and if any show signs of leaking (past/presant).
it would be a good idea to change them while you are at it.

1- Drain Down system, replace valve, replace inhiditor.
2-Turn off the other rad valve to the rad, and frezze the pipe with fauty valve, and replace.
3- use the bung type system
Only if you are confident


As MSP said use a good replacement valve Myson matchmate available from Plumb Centers, or use a Pegler valve(my choice)

gromituk

I'd have thought that it would be easy to replace a valve in a sealed system. All you have to do is remove enough water to bring the pressure down to zero. This can be done by operating the safety valve manually. You're then in the same position as if you had fitted a bung kit to a conventional system.

plumb1_2

gromituk wrote:

I'd have thought that it would be easy to replace a valve in a sealed system. All you have to do is remove enough water to bring the pressure down to zero. This can be done by operating the safety valve manually. You're then in the same position as if you had fitted a bung kit to a conventional system.

The safety valve should not be used to drain down the system, as you will have small amounts of debris passing through, and if any lodge on the seating, it will not operate correctly, and will let-by.
It is a saftety valve not a drain off.

gromituk

Good point - use a drain !!!! if there is one, or just catch the water from a valve you're removing!