Constant dribble from overflow - help!

one-non-blonde

What started off as a small drip has now become a constant dribble of warm water from the overflow pipe to the outside of my flat. The pipe is at ground level and comes through to the outside via an old air vent at the base of the wall from the same room as the gas boiler (which is behind the gas fireplace). There is also one radiator in this room. The floors are wooden but I've not managed to find any planks that could be easily lifted to have a look to see where the overflow pipe comes from. The dribbling is going on even while the heating and hot water are turned off.

Obviously I'm worried about this causing a damp problem and the expense involved in the loss of all this hot water! Could someone please give me a clue as to where the overflow pipe comes from and what I could do to stop it?

Baz_Bee_2

What type of heating installation, boiler, etc do you have? And what type of hot and cold water installation do you have? Do you have water tanks (cisterns) in the loft(?) or a combination tank, hot water cylinder or what?

It is unusual to have warm water coming from an overflow pipe, although some hot water systems do have them which is why it may help if you can give a bit more information.

one-non-blonde

Eek... now you're asking! :eek:

I have a Baxi Bermuda gas fire in the lounge behind which is a back boiler leading to a pump in the cupboard beside the fireplace then to 5 radiators, all of which have thermostatic valves. There is a Howden copper hot water cylinder in the hall cupboard outside the lounge. The hot water can also be heated electrically via a switch in the kitchen.

As for cold water, I'm not really sure. The flat is a conversion of which I only have the ground floor, so there may be a cold water tank in the attic (which belongs to the flat upstairs) or may be mains - I don't know how to tell!

I had the boiler checked and serviced just after I moved in last summer.

plumb1_2

it will be a tank overflowing,there will be 2 tanks,1 for heating and 1 to supply the not water cylinder,they will quite high up,attic is a good starting point.
the overflow pipe might be boxed in with the heating pipes,at the side of the fire place,then go under the floor to outside.

is there a hatch on the top floor,out side the other flat above you,if not you will have to ask your neigbour to see if the access is in their flat

Baz_Bee_2

As plumb1 says, with the installation you have there should be two overflow pipes. One from your cold water storage cistern (tank) and the other from the feed and expansion tank.

Do you have two overflow pipes coming out or just one (in fact there should be two per flat if they all have a similar installation). These two cisterns will probably be in the loft and you will need to gain access to them to check which of them, if any, is the problem. It is unlikely that you will be sharing these tanks with the other flats, but it is possible. So you may want to speak with your neighbours in the other flats. Do you know the overflow that is dripping is yours or are you just guessing?

Anyhow, whoever the coistern belongs to or is used by the problem is likely to be the ball valve. It will either need adjusting if the water level is getting too high, or if it is faulty it will need replacing. Replacing a ball valve is a reasonably starightforward DIY job asuming you can turn your mains water stop !!!! off. Or a decent plumber should be able to fit a new one in less than an hour.

So your first port of call should be the loft to see if you can examine the cisterns to see which of them, if any, has too much water in it. You can then arrange for remedial action as necessary.

dougk_2

The ball valve has possibly just got encrusted with limescale
Mine used to do this every few years and the solution was to just clear away the limescale with a stiff nylon brush! I could have replaced the ball valve but there wasn't really anything wrong with it!

robowen

unusual to have an overflow at ground level coming from an attic space.

Normally they would just run them out of the wall at high level.

Has this drip been around since the boiler was serviced ?

one-non-blonde

dougk wrote:

The ball valve has possibly just got encrusted with limescale
Mine used to do this every few years and the solution was to just clear away the limescale with a stiff nylon brush! I could have replaced the ball valve but there wasn't really anything wrong with it!

Thankfully limescale doesn't feature in this part of the world!

It is possible that I have a cold water tank in the folk upstairs' attic but I've never asked and we (to put it very mildly) don't see eye to eye. :wall: (OMG, I hope there isn't one... think what they could be putting in it!! :think: :eek: ) Ideally I was hoping the solution was something simple I could do without involving them (even if it did involve wrestling with the floorboards!). As the water escaping is warm I don't understand why it could be coming from the attic anyway as my hot tank is at ground level...?

Thank you all for giving this some thought and please forgive me for being DIY-ly challenged and too skint to even consider employing a plumber

one-non-blonde

robowen wrote:

unusual to have an overflow at ground level coming from an attic space.

Normally they would just run them out of the wall at high level.

Has this drip been around since the boiler was serviced ?

No, I really don't think so, but for the first few months I was here the garden was covered in yikky red chips, so any drip would probably have gone unnoticed (as it would have filtered directly down to wet the lovely concrete underneath with the surface appearing dry). It's steadily got worse since I did notice it a few months ago and is now a constant stream of water, the actual rate of flow varying (exactly when and why I haven't yet established).

This particular pipe disgorges at the front of the house which in itself I thought unusual and must therefore be positioned due to it's proximity to wherever it was coming from (and not for aesthetic reasons!). The flat upstairs have an overflow at the back coming from their bathroom but I've not noticed any others.

robowen

I think a little detective work is in order.

Assuming you can find where this overflow comes from.
and assuming there is a feed and expension tank somewhere and a hot water cylinder in someone's flat.

IF...the warm water comes from the small expansion tank, it is likely that the cylinder will have a damaged coil inside, or the coil may be split.

Because the cold feed tank is higher than the expansion tank, cold water will feed into the cylinder and be warmed up, it will then seep through the split in the coil and be pushed up into the expansion tank and then overflow.

But that's If you have the above plumbing !!

rob
p.s, can you pm me on how to do the smilies in the text, there seem to be loads of them I've not seen before.
Thanks