Dripping float valve in loft

[MyNameIsUrl]

The cold water tank in the loft has a drip about once per second, not enough to overflow as the hot water is used frequently.

I’ve read that it’s simpler to replace the whole valve than change the rubber, but I only want to do this if it’s the most robust and reliable solution.

Might the seat be cut in the same way that a tap seat can cut? Where should I get a new one – Wickes are cheap but reviews aren’t always good. My valve is 25+ years sold – will a modern one be better or just be cheap rubbish?

[bungeejumper]

These aren't rubbish, and they're not plastic either: https://www.screwfix.com/p/pegler-float ... rt-1/90110

There are many things that cause float valves to fail, and worn washers or membranes are only one of them. Hard water can encase the whole thing in one great stalactite. And the constant movement can slowly wear the brass components so that they don't move freely, and then they stick, and then suddenly the washer/membrane isn't sitting straight on the jet, and then it drips.

That said, it'll probably be simpler to swap the valve than to faff around trying to get something that'll fix a 25 year old valve. But if you still fancy a simple fix, check the split pin on which the arm swivels. If it's sticking or worn or twisted out of line, you can fix that for nothing.

BJ

[pendas]

I always replace the plastic seat at the same time as the washer. They often come together in a pack along with a new brass split pin and are colour coded for low and high pressure use. You will need the blue one for mains water pressure.

[bungeejumper]

Of course, it could be something as simple as a bit of grit (or scale, or copper swarf) under the washer. The downside of it is that, by the time you've discovered that, you might as well have replaced the whole damn thing anyway. But try holding the valve fully open for a few seconds to see whether it expels any crud. You never know, I suppose?

BJ

[jfgw]

If it is really old, it will be a part 1 valve. While these can be repaired with a suitable washer, I would recommend replacing it with a part 2 valve: https://www.screwfix.com/p/pegler-float ... rt-2/27627 .

IIRC, part one valves are still legal to connect to the main supply when used with a tank (not a toilet) if a check valve is used. Part 2 valves, by the nature of their design, incorporate their own backflow prevention so an additional check valve is not needed.

Julian F. G. W.

[Howard]

Apologies if you have already thought of this. Do you have a maintenance contract for your central heating? I have just had a replacement valve fitted in the header tank free of charge.

It was covered by my central heating maintenance contract. The plumber replaced the ball valve as a preventative measure because it was noisy when refilling after he had partly drained the system to replace a pump.

I ask because it is easy to forget what a maintenance cover includes in addition to the annual boiler service.

regards

Howard

[kiloran]

Does it still drip if you lift the arm up a bit? If that stops the drip, you might just be able to bend the arm so that the float is lower in the water, and so puts more leverage on the valve.
Not as good as a proper fix but may be good enough for now.

--kiloran

[jackdaww]

if you are clambering into the loft , install a new valve.

i've used this type with a vertical float --- no problems so far .


https://www.wickes.co.uk/Fluidmaster-Si ... Responsive

[MyNameIsUrl]

Does it still drip if you lift the arm up a bit?

No, doesn't seem to.

Not as good as a proper fix

Agreed, I'll do a proper fix, but your suggestion is useful in the meantime, thanks.

[quelquod]

Does it still drip if you lift the arm up a bit? If that stops the drip, you might just be able to bend the arm so that the float is lower in the water, and so puts more leverage on the valve.
Not as good as a proper fix but may be good enough for now.

--kiloran

Eh?

The float sets the target water level so surely if you bend the arm down a bit all that will happen is that the water level where the valve shuts will drop. No net (long-term) effect on the force on the valve itself?