Isolation Valve For Dishwasher Connection

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Hi, I have been trying to install a dishwasher, to replace a faulty one. So, it should be just one out, one in. However, on the end of the cold water copper pipe, there is an isolation valve (I think it's called), with one of those little blue levers on it, which you turn to stop the water. When I screwed the new dishwasher flexible plastic pipe onto it, then turned the lever, water started to come out of the valve. I assume I need to change this then... never done this before, please could you tell me -

1. Shall I just buy another of these levered shut off valves, or is there something better?
2. When fitting the new one, shall I use PTFE on it, or am I right in thinking that it's a compression joint, so none should be used.
3. I assume that when I remove the old one, there will be an olive trapped tightly to the pipe, how do I get this off?
4. Are these valves prone to leaking?
5. Is it just a case of taking the old one off and fitting a new one, or do I need to prepare the copper pipe in some way?

I have a further issue in that I have no way in the house of turning the water supply off. I have to use the outside stop tap in the ground but this doesn't turn it off totally, so I shall have to change the valve with the water still dripping slightly.

Sorry to be a pain, plumbing is an art form, it has to be done right or it just fails!

Any help appreciated. Thank you.

 

[Hugh Jaleak]

Whereabouts is it leaking? If the spindle is leaking then new tap is the only option, but worth checking it's not trickling back from the hose joint. In answer to your questions:

1. Same again, designed for the job.
2. Dont need PTFE.
3. Leave olive in situ. Should be able to use existing nut and olive with new tap. If not, carefully hacksaw olive off or trim pipe back and start again.
4. Properly fitted it shouldn't leak.
5. Should be a straight swap.

Try to avoid overtightening, this will crush the olive and can actually make it leak! If outside stoptap wont shut off, worth a call to Water Authority. They may replace outside stoptap FOC for you.

 

[TicklyT]

Some valves will leak water around the handle as they are turned, but seal again as soon as they are fully 'on' or 'off'.

Sometimes the rubber washer in the hose connector gets omitted or lost, allowing water to leak around the hose union threads.

You should be able to fit a new valve onto the existing pipe olive, using the existing nut (which is held captive behind the olive anyway).

A quick clean up with a pan scourer pad is enough to remove any limescale deposits or old sealant from the olive before reassembly.

Some like to add a smear of sealant or a turn of PTFE around an olive, but I have found little need for it. There is definitely no need for any sealant or tape around the nut threads.

Removing an olive can be tricky, that's why most would re-use the existing one. If you must remove it, try cutting a slot most of the way through it with a hacksaw blade. Insert a screwdriver in the slot, and twist to crack the olive. Don't cut too deep, or you will score the pipe and your new olive won't seal.
Alternatively cut the end off the pipe and fit your new olive on the now shortened pipe.
Make sure there are no dinks or scores in the pipe where the olive will sit, and clean off any paint first (pan scourer or steel wool)

 

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Great replies, thank you, I appreciate it. I think the valve is leaking around the blue lever somewhere. In fact, when I took the old dish washer out and turned that handle off, water was still trickling out of the now open end. I had to tweak the handle back a little bit to minimise it, but it still wouldn't stop completely. I cut a very small section of pipe off the old dish washer and screwed it back on, with a clamp on the cut off end, as my quick home made water stop, until the new one arrived. That is back on now until I decide what to do. Think I shall get to B & Q tomorrow and have a go at putting a new one on, leaving the olive in place as you guys have suggested. I live in hope of not having to call out a plumber, if I can sort it myself.

The stop tap (which won't fully shut off) is on my driveway, in the ground. I'm thinking that they will make me pay for a new one but will check. I really need a stop tap in the house, will need a plumber for that. I actually have two, which turn off different assorted taps, but neither will do the dish washer supply!

 

[calorific]

There will be a stoptap in the house somewhere

 

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As I mentioned before, there are two... both in the kitchen, which shut off various assorted taps, but not everything. I think that different plumbing jobs have been done at different times, and the easiest quickest route was often taken, and done as they saw fit. Meaning I have no common stop tap.

 

[Hugh Jaleak]

There may be some play in the plastic handle, if you remove it, a small adjustable spanner can be used to (carefully!!!!) turn the valve spindle slightly to shut valve off fully.
Dont go too mad, 90deg is difference between fully open and fully shut, you'll get a good shower if you turn it too much!

 

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Well, I bought a replacement valve today and thought I'd have a go at this. But I've failed unfortunately. I can't even get the old one off, can't believe how tight it is and the copper pipe is moving and bending so much it's worrying me. I did manage to turn the nut a little bit, but the rest of the valve body moved with it. And I think that's damaged it, now as well as the valve handle being faulty, it is weeping at the nut too. And I have no way of isolating the supply. Will hopefully find a plumber in the next couple of days who can sort it. Thank you for all the replies.

 

[CBF]

you need two pairs of grips/spanners you need to support the valve to stop it turning when you un-do the nut & the same when fitting the new one

 

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...worth a call to Water Authority. They may replace outside stoptap FOC for you.

Well we contacted them, and just like you said, we have managed to get them to replace it. They will remove it from the driveway where it is now, and put a new one in the pavement outside. For free. Thanks for the suggestion, at least I will be able to turn the water off to the house now properly, hopefully.
Still trying to find a plumber to change the isolation valve, am hoping to get someone early next week, it's not easy.

 

[Hugh Jaleak]

Water folk are always worth a try, worst case scenario, they say no! I dont think they mind so much if you have the old type stoptap, fitting the new plastic type sets them up for fitting a meter at a later date so I suppose does them a favour in a round about way....

 

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I was a little worried that, with them moving it outside I would lose some control over it, and that they might fit a meter at will, or I won't be able to freely use it at as I can now, or whatever. But I'm hoping this won't be the case. Had a right argument with the guy at first, he refused to arrange to have a new one put in, kept saying the old one was fine, even though it won't completely shut the water off to all the outlets. He told me to buy a freezing kit! In the end the argument got that heated, he stormed off, having already turned the stop tap off with his heavy duty key and left us with no water aside from a trickle in some of the taps. I had to phone them up again and complain, for him to come back with his boss and turn it back on. It was then, that I was told they would change it after all.

 

[Hugh Jaleak]

I dont think they can fit a meter at present unless you request it, but I think its on the cards that metering will become compulsory at some point in the future.

Not a very good representative for the Water Supplier though, he shouldn't have stormed off and certainly shouldn't have left the water at a trickle! The existing tap is not 'fine', ultimately it needs to be sorted, if they were unwilling to pay for that to be done then he should have explained the options calmly. I can only comment on my experiences with Anglian Water, but they have always been pretty good when i've come across this problem, either replacing a stoptap, or in some cases, fitting one where there wasn't one previously.

 

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I guess that, if meters are to become compulsory, then they would be fitted no matter where the stop tap was sited. Yes, the water guy was very antoginising and frustrating. Couldn't believe his reply of 'get a freezing kit' when I explained that the water couldn't be cut off to fix the dishwasher supply!

 

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All sorted at last. Managed to get a plumber out, great guy, and only charged £10 to fit the valve I had bought. Kept the old olive as suggested. Thanks for the replies and help.