Plumbing; replacing a ballvalve - talk me through this.

Hello all.

I am pretty handy when it comes to DIY and although I think I know how to do this small job, as I’ve never done this before I thought I’d seek advice first! I have all the necessary tools.

The cold water inlet ballvalve feeding the toilet it leaking (water escapes from the joint precisely where the tip of the arrow is). I don’t know if the washer or the valve but I plan to replace the whole brass ball valve. I am able to stop the escape of water by turning the ball valve (possibly this suggests it’s the washer not the valve that is leaking?).


https://i.ibb.co/wLFkNmQ/3761-EFFE-5...60-FBBFD23.jpg

https://i.ibb.co/Qn3rh8v/6862-D31-A-...B50-D2-EA0.jpg

I will stop the water at the mains. I will open the cold taps. I will drain the toilet cistern.

Is it then a case of simply unscrewing the nuts top and bottom and swapping old for new?

Should I use PTFE tape? And special precautions screwing brass to plastic? Any other clever tips of the trade before I flood the house?

Many thanks!


https://i.ibb.co/PxvcB8J/CB0938-F1-C...96-CA32207.jpg

Not an expert plumber by any stretch of any bodies imagination but I’ve never seen a shut off valve like that before and can’t figure out what or how the bit that fits into the plastic threaded pipe works?

Off to do some Googling [emoji3]

Found it, it’s called a straight service valve, learn something new every day [emoji3]

https://www.screwfix.com/p/straight-...E&gclsrc=aw.ds

So turn the water off at the mains, ensure that there is no real water pressure at the pipe work you will be opening up, drain out any existing water and open it all up.

The valve will come with an olive for the copper pipe end and a washer for the plastic pipe end but I’d put couple of turns of PTFE tape on the plastic pipe, the plastic pipe will need to perfectly butt up to the valve to make things watertight but if it doesn’t then hopefully the tape will help.

Don’t over tighten either end, you can always nip it tighter if there is a small leak.

Because the valve sits in the pipes at either end you might also need some lateral movement to remove and fit the new.

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Originally Posted by IAmATeaf

Found it, it’s called a straight service valve, learn something new every day [emoji3]

https://www.screwfix.com/p/straight-...E&gclsrc=aw.ds

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You’ve already helped me because I was looking at the wrong valve on the B&Q website! The one you show is exactly the right one; THANKS!

Oh another thing, for the lower fitting you probably won’t be able to remove the metal olive and therefore the lower fitting so may have to use the old. If this is the case put a couple of turns of PTFE tape around the old olive and toward the cut end of the pipe. Will help as you’ll be using an old olive in case things don’t quite align and seal.

Quote:

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Originally Posted by IAmATeaf

Oh another thing, for the lower fitting you probably won’t be able to remove the metal olive and therefore the lower fitting so may have to use the old. If this is the case put a couple of turns of PTFE tape around the old olive and toward the cut end of the pipe. Will help as you’ll be using an old olive in case things don’t quite align and seal.

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Thanks again. Just been googling techniques to remove old olives without special equipment; I think either way I can overcome that problem now: thanks!!!

More often than not, the original nut and olives are fine to use again. Personally, I wouldn’t advise the inexperienced to remove the old olive, unless necessary.

Be careful not to cross the threads on the plastic, don’t over tighten and you should be fine.

Don't forget to flush the loo (as you say, drain the cistern) after you have turned off the supply or you will have a tank full of water leak out as you remove the valve fittings!

I don’t know what others think but I’d be inclined to get rid of the plastic threaded toilet fill valve while You are at it. Fit a metal one.

Most likely to be the washer. The fibre ones break down over time and leak. If it is that it's a simple fix, isolate the feed (assuming mains fed so shut supply off there as the valves themselves can leak if you shut them off after they haven't been used for a long time). If you have enough play in the pipe run after you uncouple then just remove what will be a broken fibre washer and pop another on the end. If not flush the toilet to remove most water, then carefully remove water from the rest of the cistern. That will allow you to loosen retaining nut for filler valve and create enough space to switch the ring washer over.

Sounds complicated but 5 min job if that's what it is. Then do NOT overtighten the nut going back onto the plastic thread. Seat it by hand to avoid cross threading, you can also nip it a little tighter if it weeps when you turn the mains back on. As others have said, you might want to switch to one with a brass thread whilst you've got it isolated, the fluidmaster pro series are decent and very easy to set up

Thanks all!!!

It was indeed the washer…

https://i.ibb.co/kDCfB8W/5495-DBE0-7...-B1-C323-F.jpg

But I replaced the whole thing (including the olive; the old one I hacksawed off)…
https://i.ibb.co/GT6Rcxk/512-AA045-2...-F12-EF3-E.jpg

Including all new internal parts; a new fill and flush valves
https://i.ibb.co/LZBDGJP/ED614196-E7...8917582-B2.jpg

Did two toilets for £30 and about 2 hours in total. A plumber quoted me £50 to just change the washer! Glad I asked here for advice! Feels great to do such a job :)

Good work, you are hired!

Well done - sense of achievement.?

Can't believe I read through this post but am glad I did, what a helpful bunch of fellows dwell here, well done all concerned.

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Originally Posted by lewie

Well done - sense of achievement.?

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100% !

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Originally Posted by notnowkato

Can't believe I read through this post but am glad I did, what a helpful bunch of fellows dwell here, well done all concerned.

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TZUK has never once let me down. Thanks all :)