Cast iron radiator - how to ensure the valve body is tight

17 Nov 2008
Reaction score
United Kingdom
A very simple question to answer by someone in the know but anyway here goes!.
I have a cast iron radiator with valve bodies that screw directly into the radiator. I applied what I thought was copious amounts of PTFE tape to the valve thread (10 turns) but when the valve is screwed in and aligned as it needs to be, it is tight but not so tight that it can't relatively easily be twisted and thus I suspect it may leak - am I missing a trick here?
Sponsored Links
Not enough tape,and possibly not wound correctly in the same direction as the thread
Definitely wound in the right direction but noted about not enough. Rather than PTFE, would a compound be better?
PTFE is usually sufficient ,and a smear of LSX for belt and braces.
Sponsored Links
7 wraps of Gas PTFE tape but it's horses for courses, ask 4 different guys and you'll probably get 4 different answers.
Cord, normal tape, gas tape, etc .... just whatever works but they all will
Thanks all. I went with 15 wraps of PTFE with a smear of compound in the end. Won't know if it was successful for a while yet though!

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local