URGENT HELP PLEASE! boiler dripping

longwalks1

my combi boiler is dripping from the small copper overflow pipe that goes through the external wall and outside... cant actually see where its leaking from, but its dripping indoors from one of the 90 degree bends prior to it exiting the house. Could this just be where the outside part of the pipe is frozen, and the excess water/steam/condensation cant escape anywhere? Its a condensing combi boiler (WBosch). i cant get up to see the pipe outside as its 3 storeys up (maisonette)

can i warm it up any way to hopefully thaw the outside part of it? was thinking of taking a hair dryer to it?

paulsad

Yes its probably frozen - you should get it lagged or an engineer can fit a wire and sensor that auto heats the pipe to stop freezing although this is expensive. Normally you'd pour hot water on it from the o/side to melt the ice

keystone

If its a 15mm copper pipe thats leaking thats normally the output from the pressure relief valve which implies that the PRV has lifted due to too high pressure. Whats the current pressure on the system? I can think of no reason why that pipe would freeze under normal operating conditions so no reason to warm it up. If its dripping internally as well that implies that the joint hasn't been made properly.

Presumably your boiler has a condensate drain too and if anything freezes its normally that. Are you sure you picked the correct pipe?

In case this develops into something beyond my competance please advise make and model of boiler for others. Ta.

Cheers

longwalks1

Thanks people

keystone (and others) its a Worcester Bosch GreenStar 28i condensing combi bolier.

I think it is called the outlet for the pressure relief valve actually keystone, when had it serviced last year they pointed out it didnt have an 'end piece' on where its outside, and explained if pressure built up, and it released outside, it would just squirt over anyone passing, so they gave me a mushroom type fitting for the end of it, so it deflects the water bac kagainst the outside wall of the property...

The pressure is currently just over 2bar, im guessing thats quite high? It has always been around 1.4-1.5 bar, but dropped recently to 1 bar, and water pressure was pretty poor so i opened the tap on a pipe under the boiler to increase pressure a bit, if its too high, how do i lower the pressure?

Thanks again everyone for your help!!

keystone

Ahh sounds like you've possibly created your own restriction for ice to form up against and block the pipe.

The real issue is that the PRV needs checking. Once they've lifted they inevitably get carp in them and then don't reseat properly. The result is that they pass and in these temps just that small amount of water in that pipe will freeze.

It sounds as though you may have put too much pressure in causing it to lift. Presure should be between 1 and 1½ bar when cold and 2 - 2½ when hot. When it reaches 2 - 3 bar the PRV lifts so if the boiler was cold whe you topped it up to 2 thats probably the root.

You need to get someone in to check your PRV I'm afraid.

Cheers

maninthestreet

keystone wrote: »

Ahh sounds like you've possibly created your own restriction for ice to form up against and block the pipe.

The real issue is that the PRV needs checking. Once they've lifted they inevitably get carp in them and then don't reseat properly. The result is that they pass and in these temps just that small amount of water in that pipe will freeze.

It sounds as though you may have put too much pressure in causing it to lift. Presure should be between 1 and 1½ bar when cold and 2 - 2½ when hot. When it reaches 2 - 3 bar the PRV lifts so if the boiler was cold whe you topped it up to 2 thats probably the root.

You need to get someone in to check your PRV I'm afraid.

Cheers

OP states the pressure is just over 2 bar, so this is within the 2 to 2.5 range you mention.

keystone

maninthestreet wrote: »

OP states the pressure is just over 2 bar, so this is within the 2 to 2.5 range you mention.

OP said he topped it up. He didn't say if the system pressure is 2 bar when cold. If it is then I'll bet a brass farthing the PRV has lifted when the system got hot. In any event no water will flow out of that pipe unless the PRV has lifted so, with respect, I'm not sure I see your point TBH.

Cheers

longwalks1

thanks again everyone, right, heating is on now and its now between 2.5 and 3 bar, what should i do? dont want it blowing up tonight and leaking everywhere, leave it on, or turn it off completely?

Also, how would i lower the pressure in it? is it something i could do? (seeing as i raised it myself- never again)

help!!

booty40uk

Hi
Sounds as if there may be a problem with the PRV and possibly the internal joint on it also.

In the meantime, you could lower the pressure in the system yourself by letting some water out of the system via a bleed valve on one of the radiators. Just hold a bowl under it and let say a cupfull out or enough to drop the pressure to around 1.5 to 2 bar. If you let too much out, you can always top it up via the filling loop........................which you already know how to do

CLIVELESTER

Hi Keystone

" Once they've lifted they inevitably get carp in them "

Exactly how do fish get into the boiler,will they smell ?
:rotfl::rotfl::beer:

keystone

Never mind Clive, never mind.

Cheers