Hi everyone, ive recently replaced the kitchen tap and have noticed the isolation valve is leaking ever so slightly. Ive tried to tighten it as much as i can but its still dripping slightly. whats the best way forward? Would i need to get some PTFE around the thread? Thanks
That type of fitting is not designed for thread tape or sealant, it should seal as the olive is compressed around the pipe as it is tightened into the fitting. That's the theory, however, sometimes they do leak and although it is a bit of a cheat, you can apply sealant around the olive. This could be a couple of wraps of tape or a non-hardening compound (my preference). Note that it does not go on the threads but rather around the olive itself as that is where the sealing will happen between the olive and the internal face of the fitting.
‘I’ve tried to tighten it as much as I can’ - maybe a quarter turn at first is best option usually, note that over tightening the fitting can also cause it to leak ! The ‘magical’ plumbers tape won’t work here by winding it around the threads as the water is getting past the olive Get a spanner / grips / onto the flats of the fitting and ‘nip up’ a little the offending nut Dry with paper towel and see how things go at this stage Can turn valve off and remove the leaking end, take a look where olive sits on pipe and see if pipe has been ‘crushed’ under the olive (by over-tightening) As above, this can allow water to pass between olive and pipe - worth checking
Have a look for this "FLOMASTA GAS & WATER JOINTING COMPOUND 250G" on Screwfix website. Its great stuff and I've used it to resolve exactly the kind of issue you are having. As before, apply it to the olive or the face of the firting, not the threads. Another option of course would be to change the fitting and/or the section of pipework if it is easy enough to do so. A few fittings would probably cost less than the sealant.
Yes that will do fine, just a smear over the olive though, dont want it entering the pipe or on the threads.
If not used for a while, it’s probably instantly set solid in the tube ! Annoying for us diy’ers as not in regular use and seems expensive for a 1 off hit (but cheaper than getting a plumber round I realise)
To be honest, PTFE around the olive is a bit of a bodge. Lots of people do it though and if it works on a small water leak then no real harm done. Give it a try, it will probably work fine and will be a cheap fix.
Check as well it’s not weeping from the slotted part u turn, and forming on to the nut to look like it’s leaking from there. They are notorious for it. If so u would need to change the whole valve.
i see. From looking at it, it might have been leaking for a while without me knowing about it. See attached photo the condition around the nut.
If you can, isolate the water and undo the compression fitting near the elbow to see how the olive has compressed. Take a photo and post on here. As it is a kitchen tap, you probably want a WRAS approved compound so something like what was mentioned in this post or LS-X (has a long set time).
It is best to let it set if u can but in the real world u normally have to turn water back on asap. It’s brilliant stuff and will normally cure any small leaks on olives even without waiting two hours.