Rad valves - Sweating?

[PinkFloyd]

I've fitted four new radiator valves (Myson Petite) and one is appearing to, what can only be described as 'sweating' There's no water runs down the pipe, but around the nut at the base a little water seems to collect. I've given it a few tightens (1/16) of a turn and that initially creates a little more!

Any solutions? I really can't be bothered draining down the system again to take it off, fits new olive etc..... Or is it nothing to worry about? In fairness the system was completely drained, filled and only briefly run up, so the water is likely to be cold in there. My combi indicates its sitting at 1 Bar.

 

[treefitty]

It's unlikely to be sweating unless the room is very hot and the pipes very cold causing condensation.

Almost certainly a slight leak, I always found as many others on here will say its a bit of an art form using PTFE tape on radiator tails (if it is the tails that are leaking) some people say 5 wraps is enough some say 30.

If its the olive you may have crushed it through over tightening, some people also put PTFE around the olives. I don't but would give it a try if I was struggling.

 

[PinkFloyd]

It's unlikely to be sweating unless the room is very hot and the pipes very cold causing condensation.

Almost certainly a slight leak, I always found as many others on here will say its a bit of an art form using PTFE tape on radiator tails (if it is the tails that are leaking) some people say 5 wraps is enough some say 30.

If its the olive you may have crushed it through over tightening, some people also put PTFE around the olives. I don't but would give it a try if I was struggling.

The radiators are actually still off so the water is sitting in the pipes up to the valves. The valves and olives are new, but it's old pipe. I spoke with a mate who used to plumb full time, but now works offshore. His suggestion was to put some ptfe tape around the olive. Frowned upon by some, but he stated that without cutting a section of the pipe out, fitting new pipe along with another new olive, it was unlikely to stop.

I took off the valve and the olive and pipe look OK, not split or anything. So....went for the ptfe option and it appears to have worked. Fingers crossed. The pipe that the leaking valve was on has historically had little leaks as it is corroded and green. I cleaned it up as best possible before fitting the new valve, but must just be unlucky.

On the one hand I totally understand the purist view of not using ptfe tape, but on the other, what choice do you have when you get a little leak like that?

 

[JohnD]

PTFE on olives is great.

 

[PinkFloyd]

PTFE on olives is great.

I knew John would chime in with that If it works, it works

 

[Dan Robinson]

Aye, but we don't know what percentage of greatness .

 

[Armo74]

Always use it on old olives never had any real problems to be fair.

 

[PinkFloyd]

Aye, but we don't know what percentage of greatness .

Well I've got a month until the decorator arrives and the room is put back together with a new radiator also. If in that time it leaks I'll get a plumber out to fit a new bit of pipe etc, as the access hatch is easily accessible right now. I think my central heating insurance covers my pipework anyway.

That aside it could drive me batty worrying about what's leaking now as you realise how easy leaks occur, and how easily they're missed.....