Water leaking from the boiler

[mcmoby69]

if i am right in assuming its a condensing system boiler have you checked if the condesate pipe is running while the boiler is pressurised and switched off?

if the condense pipe is running whilst the boiler is off then you have a problem with your heat exchanger. to check this, pressurise the system then turn the flow and return pipes off underneath the boiler. if the pressure drops then the leak is in your boiler . as agile said check this before you get the thermal imaging camera. much cheaper.
it would be very unusual for the heat exchanger to have gone so quickly.

 

[blueagle78]

if i am right in assuming its a condensing system boiler have you checked if the condesate pipe is running while the boiler is pressurised and switched off?

if the condense pipe is running whilst the boiler is off then you have a problem with your heat exchanger. to check this, pressurise the system then turn the flow and return pipes off underneath the boiler. if the pressure drops then the leak is in your boiler . as agile said check this before you get the thermal imaging camera. much cheaper.
it would be very unusual for the heat exchanger to have gone so quickly.

Its Vaillant ecotech Plus 630. Ok I looked at the boiler and I can see three copper pipes coming out of it. Looking at the diagram/arrows I'm guessing one is inlet, then gas pipe and then outlet. So I should pressurise the system to say around 1.5 bar and then turn off both inlet and outlet valves ? Please confirm before I do this because I'm not a plumber so don't want to end up doing anything which might cause more damage. Thanks[/b]

 

[bell824]

That is coorect the two outer pipes with what looks like drain valves on them, you can isolate these with a 4mm hex/allan key they are quarter turn, i would suggest a higher pressure though maybe around the 2 bar mark,
If it has long runs of consensate you may be able to pull the pipe off just to check if its leaking.

Just to recapp pressure to 2bar isolate boiler leave of for about 6 hours, check pressure on boiler if it has dropped then boiler fault ,if not open isolation valves if it drops at that point then system fault, this should get you closer to your answer.

 

[blueagle78]

Bell thanks for very clear instructions.
I've pressurised the system to 2 bar and have turned off both valves. Would post back after about 6 hours.

 

[blueagle78]

Update: Boiler didn't lose any pressure at all while the valves were isolated but as soon as I turned the valves back to their original position, pressure dropped to 0.6bar.
Bell thanks for helping me to eliminate the boiler. So now I know its not the boiler that's cause of this pressure drop. Is there anything else I can do to eliminate say either upstairs or downstairs pipes?

 

[leytonjc]

if you have existing pipework buried under a concrete floor that is more than likely where your leak will be, probably a weak soldered joint leaking due to the increase in pressure with the new system i.e conventional system (f and e tank) to pressurised sealed system. as Agile said i would recommend an infrared thermometer, you may be able to hire either from your local tool hire shop.

 

[DP]

Often simple advice leads to results than overcomplicating the issue.

Fact. System was OK until carpets fitted.

This is the area I would be looking at initially. Pressurise system to just under 3 bar. Look for leaks (could be under the carpets), even listen for 'hissing' noise which could well be the leak. Walk across the floor bare feet- you may be able to locate the leak that way. Look for marked paint on the ceilings or blistered ceiling paper (if ceiling papered). Use you judgement to speculate where the leak might be.

 

[leytonjc]

Fact. the ceiling would have colapsed by now if he is losing that amount of water, maybe coincidence that the pressure dropped when the carpet was laid or maybe not.

 

[blueagle78]

I look for a sign of damp at the ceiling every single day but there's no sign of dampness anywhere so I very much doubt the leakage is upstairs but I could be wrong. The theory plumber told me "not sure how correct that would be" that possibly the nail (from carpet fitters) is in the copper pipe which means water is leaking slowly and when copper pipes are hot leaking water is almost fading/getting burnt out.
I'll work on the suggestion by DP and would post again tomorrow.

 

[blueagle78]

I've got couple more questions with regards to this.
Firstly, I've noticed there's one radiator upstairs which always has more air than any other radiator in the house. Could the leakage be around that radiator? Ceiling underneath that radiator/room isn't damp from anywhere.
Secondly, I'm thinking of hiring this one from HSS http://www.hss.com/g/49420/Damp-Meter.html.
Would it work from the top of a fairly thick carpet and 11mm underlay? Leakage is more than likely some where on the ground floor because there's no dampness in the ceiling anywhere to be seen by the naked eye. I've been filling up the boiler almost every day to warm up the water and the house but there's still no sign of leakage anywhere to be seen

 

[Agile]

That link does not work.

You can buy a cheap one probably for less than they would hire one to you. I have cheap ones with three lights which I sell for £5.

I would not expect that to find the leak. But it might.

I would hope that an infra red thermometer as sold by Maplins and others for £20-£30 might identify a cooler area resulting from evaporation of moisture.

Tony

 

[blueagle78]

Sorry I added a dot at the end which screwed up the link. Its http://www.hss.com/g/49420/Damp-Meter.html
I can't seem to find any infrared ones. They all have the two needles at the end. Is there an infrared one you could recommend? I really want to sort this out this weekend. Thanks

 

[Agile]

Maplin have a typ[ical one at about £29 which is regularly on sale at about £19.

Similar ones on Ebay probably around £20 plus an extortionate over price for postage like most things on Ebay.

 

[blueagle78]

Maplin seems to have few but this is the only Infra-red one I could find. http://www.maplin.co.uk/infrared-thermometer-223005
Will it do the job for me?
Thanks

 

[blueagle78]

There are still no signs of leakage to be seen anywhere in the house. I've purchased the infrared temp reader from Maplin but it'll take me a lot of time to go through all the rooms (I don't know how the pipes are running in most of the house so scanning pretty much the whole floor space). My father-in-law's plumber has suggested trying a sealer but I'm not too sure. Would you recommend I try something like? Fernox F4 Express Central Heating Leak Sealer
Please advise. I really want this leakage to be sorted ASAP now because I'm tired of pressuring the system twice a day, bleeding the radiators before I can put the heating on.