Isolation Valve replacement - tips, advice. warnings??

[Stall]

Hi,

First time poster here and not a plumber at all.

I noticed a small leak, more of a weep, on the isolation valve which leads to the cistern. The leak is at the top of the nut, so closing the valve effectively stops the leak, but obviously renders the flush inoperable. Fortunately I've got a couple of bathrooms so having one out of order for a few days isn't too much of a problem.

Anyway, having spent all afternoon yesterday looking at the problem and considering it, on the face of it I reckon its an easy fix? Please advise if its not. Basically, before I do this I'de like to ask the advise of the pro's on here as to what I need to do, what I need to watch out for, whats the worst that can happen etc.

Picture of the offending valve attached.



So, I'm thinking the following steps:

- Turn off the water at the mains
- Drain the system by opening all down stairs taps
- unhook broken valve
- put on new one
- turn the water back on.

Is it really that simple? I've bought a 15mm compression isolation valve from homebase. I don't need to do any soldering or anything?

Also, will it interfere with the heating? Should I shut that off first? And what about the hot water, do i need to drain that too? I've got the water clicking on at 5pm so its warm before we get home from work. If this needs drained as well, then I'll take the timer offline before I leave for work in the morning.

Im planning on doing this on Wednesday night, any hints, tips, advice, warnings etc. before hand will be much appreciated. I don't want to flood this house, particularly this close to Christmas.

Thanks in advance

 

[buckley plumb]

Hi,

First time poster here and not a plumber at all.

I noticed a small leak, more of a weep, on the isolation valve which leads to the cistern. The leak is at the top of the nut, so closing the valve effectively stops the leak, but obviously renders the flush inoperable. Fortunately I've got a couple of bathrooms so having one out of order for a few days isn't too much of a problem.

Anyway, having spent all afternoon yesterday looking at the problem and considering it, on the face of it I reckon its an easy fix? Please advise if its not. Basically, before I do this I'de like to ask the advise of the pro's on here as to what I need to do, what I need to watch out for, whats the worst that can happen etc.

Picture of the offending valve attached.

View attachment 9457

So, I'm thinking the following steps:

- Turn off the water at the mains
- Drain the system by opening all down stairs taps
- unhook broken valve
- put on new one
- turn the water back on.

Is it really that simple? I've bought a 15mm compression isolation valve from homebase. I don't need to do any soldering or anything?

Also, will it interfere with the heating? Should I shut that off first? And what about the hot water, do i need to drain that too? I've got the water clicking on at 5pm so its warm before we get home from work. If this needs drained as well, then I'll take the timer offline before I leave for work in the morning.

Im planning on doing this on Wednesday night, any hints, tips, advice, warnings etc. before hand will be much appreciated. I don't want to flood this house, particularly this close to Christmas.

Thanks in advance

sort of but if its dripping from the top nut it will be the fibre washer . be careful as the chrome nut can easily strip the plastic thread on the float valve .

 

[mike-c]

Not being funny but have you tried tightening it?

 

[stevetheplumber]

probably going to need a new ballvale as its posible the plastic tail is cracked get one with a brass tail

 

[R1CKY]

As Buckley Plumb said, most likely a fibre washer that needs replacing, again repeating what he said, be very careful when re-tightening as the plastic threads are very easy to cross thread.

Bit of advice, wind the top nut on to the plastic thread before fully tightening the lower compression nut. That way the valve will be loose and have some play so you'll less likely to strip the plastic thread.

 

[secret squirrel]

What I'd do is turn the water off to the house and then replace the whole thing with a flexi hose and a new isolator.

I despise, yep, despise those connectors, I have nothing but trouble with them.

 

[Stall]

Not being funny but have you tried tightening it?

I tried that yesterday, it seemed to make the leak worse. It was either the tightening or the water getting released back through it, but the weep was definitely harder after I tightened it.

 

[Stall]

probably going to need a new ballvale as its posible the plastic tail is cracked get one with a brass tail

If it is cracked and that bit also needs replacing, does that start to get into the realms of beyond the skills of the average non plumber?

 

[Stall]

As Buckley Plumb said, most likely a fibre washer that needs replacing, again repeating what he said, be very careful when re-tightening as the plastic threads are very easy to cross thread.

Bit of advice, wind the top nut on to the plastic thread before fully tightening the lower compression nut. That way the valve will be loose and have some play so you'll less likely to strip the plastic thread.

Do you mean fully tighten up the top section to the plastic pipe, before going to work on the bottom connector?

 

[Avatar]

it isnt a standard isolation valve anyway as it looks like 15mm compression at the bottom with a 1/2 inch female at the top to screw onto the toilet valve.

it may well be who ever fitted it did not do so carefully and has fouled the plastic thread. It is possible at a pinch to saw the end off but if you remove the connector you will be able to see it this is so . . ..

Worse case its time for a new fill valve as well!

 

[Veggie Dave]

it isnt a standard isolation valve anyway as it looks like 15mm compression at the bottom with a 1/2 inch female at the top to screw onto the toilet valve.

It's a standard service valve.

 

[Pipedream]

If the plastic thread on the inlet valve is damaged you will need to replace it. It is worth buying one with brass shank, less chance of crossing the thread

 

[Avatar]

it is not a standard service valve which I mean 15mm compression both ends . . . ..

You wont get one like he wants from homebase thats for damn sure!

 

[Dotty]

it is not a standard service valve which I mean 15mm compression both ends . . . ..

You wont get one like he wants from homebase thats for damn sure!

It is a standard service valve. You're thinking of a compression to compression ballafix valve. But as said previously, New 1/2" fibre washer, possibly new ballvalve.

 

[Plum Bob 66]

If the plastic thread on the inlet valve is damaged you will need to replace it. It is worth buying one with brass shank, less chance of crossing the thread

flidmaster pro (brass bread) £11.98 on flea bay, job done.:wink5:

 

[Plum Bob 66]

flidmaster pro (brass bread) £11.98 on flea bay, job done.:wink5:

Dohh (brass thread) !!!

 

[Stall]

Guys, thanks for the responses, much appreciated. In particular the heads up that the parts i need might not be standard.

I really fancy doing it myself, but it wont be tonight if i dont have the bits, and considering christmas coming soon i might have to weigh up getting a plumber in. Last thing i need is the wife going mental because iv flooded the house just before Christmas.

Brother in laws got a mate who is a plumber, might be worthwhile investigating if he wants a homer.

Cant imagine it would take a real plumber very long to fix it.

 

[TomLane]

Guys, thanks for the responses, much appreciated. In particular the heads up that the parts i need might not be standard.

I really fancy doing it myself, but it wont be tonight if i dont have the bits, and considering christmas coming soon i might have to weigh up getting a plumber in. Last thing i need is the wife going mental because iv flooded the house just before Christmas.

Brother in laws got a mate who is a plumber, might be worthwhile investigating if he wants a homer.

Cant imagine it would take a real plumber very long to fix it.

Probably a good idea to get a plumber in. In some circumstances there's no replacement to getting a professional in who you can rely on to fix the problem. I'm sure in the long run you'll agree. Perhaps if you had a little more time & at a less pressurised time of year you could spend your time doing it yourself, but for now an expert is the best course to take.