Repalcing Cold water Tank Float Valve

[sheslookinhot]

Quick question please.

I assume the replacement of this valve is straightforward. 3/4" part 1 HP. I also assume the cold water pipe slides into the brass float valve. However I would like to know what seals the copper cold water pipe to the brass valve body . Is there an olive below the screwed ring holding the cold water pipe in place or is it by plumbers tape ?

What size of olive would it be ? The Float Valve was supplied by B&Q and came without an olive.

If it was an olive could I chance slackening the nut withdrawing the pipe from valve, replace valve and re-tighten ?

Thanks

 

[gavinda]

it depends, sometimes it uses a 15mm compression connection, if present just use a smear of sealing compund on the old one.

sometimes however it uses a skinny 1/2 fiber washer, which you MAY get away with reusing, but should really be replaced.

 

[TicklyT]

Most use a tap connector with a fibre washer as the seal.

You might not need to replace the washer, but get a few spares just in case.

Drop one washer down the hole in the ceiling the water pipe comes through, and lose two in the loft insulation.

Fit the fourth one to the float valve, restore the supply and check everything is working.

If you have any washers left over, drop them inside the cold cistern where they will be out of reach until they get drawn down the pipework and cause a blockage one evening. It's best if you can arrange for this to happen just as the rest of the family arrive to spend the Christmas break with you.

 

[HERTS P&D]

Or turn the water off and just replace 1/2 of the valve that is inside the tank.

I normally do this live if the water can not be turned off, it helps to have the cold kitchen tap and garden tap open.

Andy

 

[sheslookinhot]

I'll get a few washers and replace one. Is there a standerd size ?

I want to replace the whole thing althought likely to be a simple reason it is dripping.

It leaks from the outlet into the tank, even although the float arm is held up as far as possible.

 

[Burnerman]

If the connection has a fibre washer, then its a typical tap connector one - 1/2". B&Q etc do a variety of these in packs.
Its possible, but less likely, that the feed pipe has an olive (15mm) behind the back nut - only a pic will help here! If it has, use the old nut / olive with some sealant.
Type 2 valves are easier to adjust, and have a spout that can alter the flow from the valve.
If the original is type 1, there's a good chance that you only need a plain rubber washer to fix this...the split pin is pulled out, the float arm drops and the plunger, with washer, follows.
Either way, you need to ensure that the new - or repaired valve - drops vertically with the water. Its surprisingly easy to twist them during reassembly!
John

 

[sheslookinhot]

John

what do you mean the valve drops vertically with the water i.e the water flows vertical down from the valve ?

 

[Burnerman]

What I mean is, the float must rise and fall vertically as the water level changes....after messing about with the valve, its easy to twist it from its original position without realising - especially if its difficult to see into the tank!
John