Water dripping from outside wall when heating on

Scotbot

Noticed a leak on the ceiling last week. Under the bath bur its the external wall where the leak is worst. The wall outside behind the waste pipes is also wet. Called plumber out yesterday and he said the overflow pipe under the bath had become detached. 

This morning stain on wall getting bigger. Went outside and noticed steady drip from the hopper where the pipes are and water running down the wall. The heating was on. Turned it off and the drip stopped. Turned heating back on drip starts again.. Pressure on boiler low

 The plumber was expensive and didn't give me a receipt so wary of using him again.as if it goes above excess on house insurance I can claim.as I am covered for water damage. Boiler under contract with heating company.also have another plumber booked Tuesday to replace weeping heated towel rail

Any idea what the leak is and who should I call?

grumpy_codger

I think you have to explain everything better and possibly post some photos... 

Ceiling, wall, inside, outside, hopper...- ??

Have the plumber fixed the detached pipe?

Does the hopper drip because of overflowing? Is the boiler on the first floor? Does the condensate pipe from the boiler go to the hopper? ...

Vortigern

1. Check hopper for blockage.

2. Top up boiler pressure, bleed radiators, top up again.

3. Check your condensate pipe. Usually plastic pipe. Does it discharge into the hopper?

4. Check PRV discharge pipe. Usually copper and turned in to the wall. Should not drip but frquently they do.

Scotbot

Hopper not blocked. Condensate pipe goes into hopper. Boiler on 1st floor

FreeBear

The downpipe is blocked. You have a significant amount of water overflowing the hopper and soaking the wall.

Clear the downpipe and any underground drainage, and let the wall dry out.

Scotbot

FreeBear said:

The downpipe is blocked. You have a significant amount of water overflowing the hopper and soaking the wall.

Clear the downpipe and any underground drainage, and let the wall dry out.

The downpipe is not blocked I have e already checked that

ThisIsWeird

Scotbot said:

Hopper not blocked. Condensate pipe goes into hopper. Boiler on 1st floor

Useful pics. And you've cut an inspection hatch in the ceiling. So, what do you see up there?!

That is clearly significant water ingress, and could be coming from the left, the right, or straight ahead :-) So, what do you actually see up there?

Lorian

Get a watering can of water and pour in the hopper and see what happens.  Looking at the marks when it's over topping some will be going in that air brick.

grumpy_codger

Scotbot said:

FreeBear said:

The downpipe is blocked. You have a significant amount of water overflowing the hopper and soaking the wall.

Clear the downpipe and any underground drainage, and let the wall dry out.

The downpipe is not blocked I have e already checked that

Then it's some pipe that is leaking - one out of five going to the hopper. And if it drips only when the boiler is on, then it's the condensate pipe.

Scotbot

Thanks w8ll get plumber to check condensate pipe