Leaking rad valve

km79

Noticed a pool of water under downstairs rad last night (central heating has been off for a few weeks)
It's coming from one of the flow valves . I have the nut a turn clockwise with the spanner last night but the towel underneath was wet this morning.
Will I try that again (I'm afraid of over tightening it ) or just call a plumber

Wearb

Is this a valve that you regularly turn on and off ? Usually a little turn on that brass nut cures it.

If not get a bit (about 70/80mm) of ptfe tape and twist it around its axis to change it from ribbon shape to string shape. Remove the nut and pack the ptfe around the spindle. Replace the nut and gently tighten.

As with all such jobs: Have lots of towels handy and know how to turn off the heating water supply before working on it. Thing do go wrong sometimes and it's best to be prepared.

Sleeper12

Can you post a photo

km79

Wearb wrote: »

Is this a valve that you regularly turn on and off ? Usually a little turn on that brass nut cures it.

If not get a bit (about 70/80mm) of ptfe tape and twist it around its axis to change it from ribbon shape to string shape. Remove the nut and pack the ptfe around the spindle. Replace the nut and gently tighten.

As with all such jobs: Have lots of towels handy and know how to turn off the heating water supply before working on it. Thing do go wrong sometimes and it's best to be prepared.

Had been turning most rads on and off for first last few years until I noticed a slight leak in a diff one before so I stopped doing that
So this would not really have been touched this year.
Left towel under it last night and it's wet this morning so prob need to sort it this evening .
One thing I noticed is that the spindle nuts on this rad appear much more corroded than any of the others
Also it's a sealed pressurized system if that makes a difference to switching off water supply ?

Wearb

Doesn't make a difference that it's sealed. You will be so glad that you can turn it off if needed that a little water on a few towels won't matter.

As sleeper said, post a pic.

My ptfe solution should work and doesn't cost much to try. Btw you don't need water off to do that, just know how to turn it off .... just in case.

km79

Wearb wrote: »

Doesn't make a difference that it's sealed. You will be so glad that you can turn it off if needed that a little water on a few towels won't matter.

As sleeper said, post a pic.

My ptfe solution should work and doesn't cost much to try. Btw you don't need water off to do that, just know how to turn it off .... just in case.

Ok thanks I'll try and nip home and post a pic in an hour or two
Should i also turn the valve to off?
I left it in the middle as in the off the pressure was building up behind it anyway

km79

Where should I be looking at turning off heating water supply ? Is it in the hot press

mrskinner

You need to watch "how to repair a leaking radiator valve" on YouTube. It probably is not the compression nut that needs attention but the spindle. Just tighten this a tiny bit and see if leak is cured.

km79

mrskinner wrote: »

You need to watch "how to repair a leaking radiator valve" on YouTube. It probably is not the compression nut that needs attention but the spindle. Just tighten this a tiny bit and see if leak is cured.

It is up around the spindle that it's coming alright I believe

Wearb

mrskinner wrote: »

You need to watch "how to repair a leaking radiator valve" on YouTube. It probably is not the compression nut that needs attention but the spindle. Just tighten this a tiny bit and see if leak is cured.

Isn't that what I have been writing about ....

km79

Wearb wrote: »

Isn't that what I have been writing about ....

it is
Going to try that this evening but will post pics first and also post pic of what I think is the water heating cut off valve if I can find it !

km79

That is the offending valve

km79

This the valve on the other side which also appears to have had a dribble of water at some point but not as much

Also the CH pipes in immersion
There is no red stop cock. Maybe it is in attic as the two cross cross pops go up the way
The only red stop cock is on opposite side on a pipe running from bottom of immersion up

Sleeper12

It looks like the gland nut needs tightening. Just a pinch, maybe a quarter turn.

km79

Sleeper12 wrote: »

It looks like the gland nut needs tightening. Just a pinch, maybe a quarter turn.

Will try that so
I'm afraid of damaging it though !
Quarter turn clockwise ?
Just to be doubly sure this is the one in question

km79

This one

Sleeper12

km79 wrote: »

Will try that so
I'm afraid of damaging it though !
Quarter turn clockwise ?
Just to be doubly sure this is the one in question

Yes, clockwise. Just a tiny bit. If still leaking then a tiny bit more etc.

The gland nut can loosen from turning valve on & off over the years.

km79

Sleeper12 wrote: »

Yes, clockwise. Just a tiny bit. If still leaking then a tiny bit more etc.

The gland nut can loosen from turning valve on & off over the years.

Ok will try that again so
Also bought some plumbers tape
Regarding the water switch off is that likely to be in the attic now ? May as well figure it out now While I'm at it

Sleeper12

km79 wrote: »

Ok will try that again so
Also bought some plumbers tape
Regarding the water switch off is that likely to be in the attic now ? May as well figure it out now While I'm at it

I think you said its a closed pressurized system? The water should already be off if this is the case.

km79

Sleeper12 wrote: »

I think you said its a closed pressurized system? The water should already be off if this is the case.

Yes closed pressurized system
To top up I need to open 2 valves beside boiler
That's what I was hoping was the case but someone else mentioned I had to switch it off somewhere else

Wearb

Post a pic of the two valves. One usually does the job.

km79

Wearb wrote: »

Post a pic of the two valves. One usually does the job.

Wearb wrote: »

Post a pic of the two valves. One usually does the job.

There is a red mains stop cock
And then one black one under gauge to control the flow into the system I think
I've topped it up occasionally before
Pressure has now dropped to near zero so will have to bleed etc I assume
Monitoring the rad for a few hours/ days first as leak seems to have stopped ........

km79

Leak is now just an occasional drop
Maybe one every half hour or son
Not fully sorted but improved
However the nut is fairly stiff. I really don't think I should force it anymore ........
Is it possible the leak has only stemmed because the water pressure in the system is now so low ?

Wearb

Will probably leak a bit more when pressure is increased. There really isn't a need for the red valve in that situation. The black valve should be used as on and off and the opposite end of that assembly should be adjusted so that when the black valve is fully opened, the pressure doesn't go past 1.5 bar or there abouts. That way when bleeding a radiator, you can leave the black valve open until finished. The pressure will be controlled (if set correctly) by the valve and all that needs to be done is to turn off the black end when finished.

The need for regular bleeding will damage your heating system and the cause should be sorted, as you are now doing.

km79

Wearb wrote: »

Will probably leak a bit more when pressure is increased. There really isn't a need for the red valve in that situation. The black valve should be used as on and off and the opposite end of that assembly should be adjusted so that when the black valve is fully opened, the pressure doesn't go past 1.5 bar or there abouts. That way when bleeding a radiator, you can leave the black valve open until finished. The pressure will be controlled (if set correctly) by the valve and all that needs to be done is to turn off the black end when finished.

The need for regular bleeding will damage your heating system and the cause should be sorted, as you are now doing.

Thanks
I had needed to bleed regularly before as I had stupidly been opening and closing the refs in various rooms for a few years until I spotted one of them leaking when it was off so I stopped doing it

As regards this valve now . The nut is very tight. I'm really reluctant to try and force it anymore . Maybe I'll go for the tape assuming I can take the nut off without the place flooding ?
Or else call a plumber !

Wearb

Removing that nut wont flood the place unless something VERY unusual happens. You now know where to turn it off anyway and as said have a few towels ready. You may have to do the ptfe thing a few times until it stops it, but is is quick and easy to do.

km79

Wearb wrote: »

Removing that nut wont flood the place unless something VERY unusual happens. You now know where to turn it off anyway and as said have a few towels ready. You may have to do the ptfe thing a few times until it stops it, but is is quick and easy to do.

Those stop cocks are always set to off so therefore the central heating water supply is always off is my understanding ?
I'll give it a go at the weekend I think
Many thanks to ye both for all the help

Wearb

km79 wrote: »

Those stop cocks are always set to off so therefore the central heating water supply is always off is my understanding ?

Yes, then it's always off, as it should be.

km79

Successfully stopped leak in that valve
However there is a leak in the other one too
I repacked it as I did the other one BUT the nut on top won't thread back in properly
After inspecting it I think one of the threads on it may be damaged
Is it possible to buy nut or doni need to buy entire valve ?