Drip, drip, drip. Overflow pipe gets on my "To Do"

[FataMorgana]

I went into the attic and took a couple of photos of the small tank from where the dip down the over flow pipe originates.

What I suspect is that there is a small drip into the tank from the ball cock and was thinking of simply replacing siad ballcock assembly.

Do I need to take the whole assembly out and unscrew (?) it from the tank in its entiretity or do I replace the ballcock as there is a split pin which seems to suggest that I can simply replace this part.

If I undertake to remove the whole assembly I assume I turn off the mains first!

See 2x images for the tank as it looks.

Thanks
Mr NotPlayedWithThePlumbingBefore

 

[ChrisOxford]

Best plan is to replace the whole lot, i.e. the ball cock (more usually known as a ball valve, or ideally, a float valve) and the float. They're cheap enough.

The type I prefer for tanks are the "part 2" ones, see here: http://www.screwfix.com/p/pegler-prestex-float-valve-part-2/27627

Float itself here: http://www.screwfix.com/p/round-ball-float/19902

As you say, you'd need to isolate the water coming into the float valve, then unscrew the "tap connector" which attaches the pipe to the float valve. Then, unscrew the nut which secures the float valve to the tank and remove the old float valve.

Fit the new one to the tank in the same way. You'll need to use a nice new 1/2" red fibre washer on the tap connector (and make sure you scrape off the old one) to ensure a good seal between the tap connector and the new float valve: http://www.screwfix.com/p/fibre-washer-pack-of-100/33589

Adjust the float so that the water shuts off when the water's up to the right level... usually an inch or two below the level of the overflow/warning pipe. You can bend the arm of brass float valves if necessary, but support both sides of the bit you're bending to prevent stressing the bit where the arm's hinged.

Double check that there are no drips from the tap connector and keep an eye on it for a while before you leave the house, just to satisfy yourself it's all fine.

Not a difficult job, but some lofts are horrible to work in and the consequences of a leak in the loft are obviously potentially quite severe so get an expert in if you're not confident. At the very least, do it when there's someone else in the house (to switch off the water in a hurry if there's a problem), with good lighting, and at a time when the DIY shops are open in case you need more parts.

Good luck.

 

[Charnwood]

A tip for the future; putting black tape over an overflow is not a good idea.

 

[ChrisOxford]

Good point, just seen the pics

 

[JohnD]

if the new valve assembly is the same as the old one, you can often do a quicker job by undoing the large nut that holds the valve onto the spigot that comes through the side of the tank.

A useful tip is to take the old one downstairs afterwards, clean and rewasher it and put it in a plastic bag next to the tank ready for next time you have this problem. It is far easier to rewasher it at your leisure when you are in no hurry and have plenty of light.

You can get a cone, washer and new split pin as a repair kit very cheaply if it is a brass valve. The plastic ones are so cheap they are hardly worth repairing.

BTW you say it is "the small tank" It looks like the Feed and Expansion Tank for the boiler and radiators. You can recognise it because it will be about 2 ft x 1ft x 1ft and will have a thick layer of mud at the bottom. In your case, the drip will have washed away the anti-corrosion chemical, so your radiators will be going rusty from the inside. If you can do basic DIY plumbing this is not difficult to deal with. The chemical will cost about £15 (plus the same if it has been dripping for long and you need to do a chemical clean to remove the rust particles and sediment from the radiators). If you are lucky there will be a sticker, label or empty bottle to show what chemical was used before.

Sediment in the CH system is the cause of a great deal of blockages, failures and grief, so do it before winter comes.

To disagree with Chris O, as it is the CH F&E tank, adjust the float so the water depth is about two inches above the feed pipe near the bottom. This gives plenty of room for expansion and reduces the risk of pumping-over. Bale out all the mud and sponge the tank clean while you have the water turned off. Clean out all the rust flakes as well or they may cause a blockage. Put a lid on it to keep out dirt and drowned wildlife.

 

[ChrisOxford]

The plastic ones are so cheap they are hardly worth repairing.

I agree, but the brass ones are so cheap in real terms too that, if you're up to it, replacement is more likely to effect a longlasting cure than refurbishment, IMHO.

To disagree with Chris O, as it is the CH F&E tank, adjust the float so the water depth is about two inches above the feed pipe near the bottom.

Thanks for the tip