Working on bath hot water pipe

[dido24]

I changed my bath shower mixer tap in my upstairs bathroom at the weekend but my pipework is imperial three quarter inch and I couldn't stop the tap connector from leaking. The access is really tight so I couldn't get the PTFE tape to the threads despite trying for hours. I spoke to a friend who recommended cutting the pipe down and using a flexi tap connector how stupid was I to take that advice the compression joint to the pipe appears to be ok but when I turn the water back on it still has a very slight leak. I tried PTFE around the olive which worked but then the water very slowly seeped out of the top of the nut. I read this forum changed the olive and bought some LSX. Now the slight leak is back at the olive. I will probably go back to using copper pipe but my problem is that since I cut the pipe there has been water which sits at the top of the cut and if I soak it up the water goes down the pipe for a second then comes back so I have to work with a bath towel and various cloths which become saturated really quickly. This seems like a gravity problem but I don't understand why there is so much water. I have made sure that the hot and cold valves on the cylinder are turned off completely and have left all the hot taps in the house open but it makes no difference. Does this mean that my shut off valve isn't working properly or could something else be going on.

 

[SimonG]

I honestly think you should bite the bullet and get a plumber in. Post your location, somebody on here may be close enough to help.

 

[dido24]

Thank you for your reply but I am not in a position to do that. I am quite competent at pipework and changing taps and valves. I just need to understand what is going on with the water in the pipe.

 

[PlumbBobBob]

it does sound like your gate valve on the hot side is letting by

 

[SimonG]

Best of luck.

 

[Bernie2]

Hmm! Are you using an imperial ring when you connect the metric fitting on to the imperial pipe? I know metric nuts and rings fit on imperial pipe but you have problems with leaks like you seem to be having. Some compression fittings you may have to change the back nut as well.

 

[Paulus]

Have you opened your downstairs taps to drain off the water retained in the pipes?

 

[dido24]

Hi, thanks for your reply. I am using a 22mm to 3/4 inch flexible tap connector and the olive is therefore imperial size.

 

[dido24]

Yes I opened all the hot water taps upstairs and downstairs. Thanks anyway.

 

[dido24]

Thanks for your reply. I did think that this might be the problem but hoped that it was accumulated water in the pipes somehow being caught in a vacuum and that there might be a solution.

 

[dido24]

it does sound like your gate valve on the hot side is letting by

Thanks for your reply. I did think that this might be the problem but hoped that it was accumulated water in the pipes somehow being caught in a vacuum and that there might be a solution.

Read more: http://www.ukplumbersforums.co.uk/p...orking-bath-hot-water-pipe.html#ixzz22lRCSR7f

 

[JCplumb]

Hi, thanks for your reply. I am using a 22mm to 3/4 inch flexible tap connector and the olive is therefore imperial size.

The olive in a 22mm to 3/4" tap connector is on the 22mm side and therefore not imperial. The 3/4" bit is the part that connects to the tap and has a washer in, not an olive.

 

[petercj]

Have you opened up any showers on the system - put the shower head in the tray or the bath so that it drains.

Also, have you tried opening and closing the valves several times - gate valves in hard water areas are buggers for letting water pass when they haven't been used for a while.

If you've done all of the above with no success - switch off at the main stopcock and drain the system.

As for the leaking olive, I'd be inclined to start again with a new olive - clean the pipe with some wire wool, make sure the surface is good, and then wack it up tight with a new olive and forget the tape.

If that fails, go for a good quality 3/4" push fit.

 

[dido24]

The olive in a 22mm to 3/4" tap connector is on the 22mm side and therefore not imperial. The 3/4" bit is the part that connects to the tap and has a washer in, not an olive.

The olive was a very snug fit on the pipe before compression. Once compressed I undid the connector to check that the olive was properly compressed and it was. Thanks anyway

 

[dido24]

Have you opened up any showers on the system - put the shower head in the tray or the bath so that it drains.

Also, have you tried opening and closing the valves several times - gate valves in hard water areas are buggers for letting water pass when they haven't been used for a while.

If you've done all of the above with no success - switch off at the main stopcock and drain the system.

As for the leaking olive, I'd be inclined to start again with a new olive - clean the pipe with some wire wool, make sure the surface is good, and then wack it up tight with a new olive and forget the tape.

If that fails, go for a good quality 3/4" push fit.

Thanks, I'll give this a try

 

[petercj]

If you are handy with a blowlamp, another way could be to leave the flexi in place, and put it to a piece of 22m, and then use one these to join the 22m to the 3/4 copper. Cheaper and less hassle.

Conex - Primaflow - Crosco Solder Ring Imperial - Metric Adaptor ( Copper Fitting: 22 mm x 3/4)

 

[Bernie2]

If the ring (olive) is copper they often squash up to much. As JT said the 3/4" usually applies to the 3/4" bspt threads of the tap not the 22mm of the pipe. Usually a brass imperial ring with a bit of jointing paste does the job. Lets be honest if its tight behind the bath no way do you really want to be taking a blowlamp behind there. If the bath is made of Acrylic you may very well be setting it alight. And it seems you can't get all the water out of the pipes so compression would seem the best way to do it. Just to be sure ask the merchant for a 3/4" brass imperial ring or olive.

 

[petercj]

Or put something between the torch and the bath, if it is plastic, which no doubt you are quite capable of working out for yourself.

 

[galaxy_plumbing]

can you post a pic how it looks now?

 

[petercj]

Even if the OP can buy 1 x 3/4" olive, it might not work with the nut on the flexi.

 

[kirkgas]

Hi, thanks for your reply. I am using a 22mm to 3/4 inch flexible tap connector and the olive is therefore imperial size.

i think the label on the flexi is confusing you, 22mmx 3/4" will refer to pipe size as 22mm and female end for the tap as 3/4"
so as you are competant with pipework what you need is to dump the flexi, and buy a 22mm compression straight coupling, a 22mm x 3/4" olive (which goes onto the old pipe instead of the one in the coupling) then get a 3/4" x 22mm tap adaptor and a small cutting of pipe, you could use the flexi but they are mince, haha, the tap adaptor comes with a fibre washer but some are not great and i do tend to use ptfe tape as well, a wee tip to put ptfe on an inside bath tap is to get a pencil and wrap some ptfe tape round it, then you can unwrap the ptfe onto the tap by turning the pencil round and round the tap ( guff description to be honest but try it and you will see what i mean)

 

[petercj]

If the OP is going to remove the flexi and use ptfe, he just as well use the original pipe-work and make the one joint.

 

[REDSAW]

Thank you for your reply but I am not in a position to do that. I am quite competent at pipework and changing taps and valves. I just need to understand what is going on with the water in the pipe.

sounds like it!.

unless you live in london? for £40 best getting someone in as there may be problems later on.

otherwise, slap a push-fit to 3/4 flexi on it...

 

[Best]

Yes, to be honest, you are obviously well out of your depth. A proper 3/4" olive (better a heavy type) will seal no bother at all. If you used a 22mm olive, as it seems, then danger of it twisting on pipe & as said, if it's a copper olive, it can be crushed flat if overtightened. I would recommend paste also.
Water in the pipe is usually a valve passing, so either bung the c/w tank or drain all. I would add that a classic mistake for a diyer is to try to work at hot pipe when an immersion heater or boiler is heating the hot tank at same time & keeps expanding the water into the hot pipe!

 

[dido24]

Update
I replaced the gate valve on the hot water supply pipe which cured the water problem.

I then bought some imperial olives, used LSX above the olive and on the tap connector thread just to make sure. It's been two weeks and it's all dry as a bone!

Thanks very much to all of you who posted helpful suggestions - I really appreciate your advice.