Leaking radiator tails - new install

[diy_dude]

I installed a radiator in my kitchen last night - a single panel from screwfix. The valves are Danfoss RAS-C2 complete with lockshield.

I wrapped PTFE around the tapered screw on the tails and tightened them into the radiator about as tight as I would do a compression nut. Plumbed it is and it leaked about 1 drip every 10 seconds from the radiator - tail join. So I tightened up the tail again and it appeared to stop leaking.

Next morning the floor was a bit wet, I would guess half a dozen drips had come out, so I tightened it again - as tight as it would go. It leaked again this morning, but only 1/2 drips.

I am doing something wrong? I don't like tightening it up quite this much and don't want to damage anything.

 

[burygas]

Taping the thread is pointless as it is the olive that creates the seal.

Put some jet blue or similar around the olive and re-do.

 

[Rico99]

Hi there,

Common problem easily sorted.

Firstly Burygas, he is taking about the tial into the rad not into the valves.

Diydude, problem is not enough PTFE on the tail threads.

Shut of your rad valves disconecct and drain the rad.
Remove the offending tail and reapply the PTFE tape. It takes load to get the right seal about 10 normally does it.

Put enough on there so that you can only just get the thread to bite in the rad and then tighten up as much as possible.

Rico

 

[diy_dude]

I think I was a bit frugal with the PTFE, I only put 2-3 turns on.

I have put loads on this time, as you said just enough to bite the thread in the radiator. No drips yet, but will have to wait until the morning to be sure.

Thanks Riko99

 

[TicklyT]

Some taper joints like radiator tails require a heck of a lot of PTFE tape.
The threads cut in radiators are often so poorly finished they resemble a ploughed field rather than a clean, smooth thread with nicely rounded crests.

The rags and burrs of metal hanging off the threads rip straight through the first few layers of tape until they get choked up with the shavings they cut. Only when they can no longer cut into the PTFE any further do you start to get anything like a seal in the joint.

 

[Axel]

Back to traditional methods: I am growing lots of hemp in my garden. No more PTFE for me.

 

[kevplumb]

yer cant smoke ptfe

 

[diy_dude]

All is better now. I think my original attempt must have a made the thread cleaner as it all went smoothly with lots of PTFE. Do drips for the last couple of days so I am a happy man.

Thanks for the advice.