Baxi combi pressure

[Texpis]

Hi all
Newby here hope you can help.

I have a Baxi combi 105e over the last few months it has needed regular topping up of the pressure I have searched all the obvious points but could not find a leak. Problem is all the downstairs pipes are in concrete floor. The pressure will not stay up at all I pressure to 1.5 bar and it drops within 30 mins or less. It seems to take gallons of water but no signs of water anywhere in the house. With the amount of water going in I cant believe it wouldn't show up anywhere. I have a home care from the gasboard who are adamant it is a leak under the concrete and of course this isn't covered. I have tried filling the boiler and isolating the heating valves and the pressure still falls this point to me to the boiler. Is it possible to have a leak from the central heating to the hot water? is there anything else I can check?

Mick

 

[namsag]

check pipe that goes outside is not drippin is it an E or HE as if later it may be leaking through condensate pipe

 

[Texpis]

Thanks for the reply there are no drips from the outside pipe. The amount of water I am putting in I would expect to find something if external.

Mick

 

[baxpoti]

If it is a HE boiler

Isolate power to boiler

Take the front cover off and drop down the panel

Charge to 2bar and observe the condense trap, is water trickling through?

If it is a Standard efficiency

Check the PRV pipework this should be dry

 

[tonybhoy]

Could be water is going into the condensate waste that is if the boiler is a condensating boiler?

If it is then your heat ex is burst or recouperator (latent HEX)is burst.

When you fill up the boiler take the waste apart to see if water is going into the condensate waste.

 

[Texpis]

Hi All it is a 105e not a HE is there a test I can try on this system?

Mick

 

[tonybhoy]

Perhaps your iso valves at the boiler are passing?

You need to ensure they aren't when you test the boiler.

Sounds like a burst pipe to me mate.

 

[namsag]

JUST checking it is the 2 isolaters on the outside 22 mm pipes you are turning off

 

[Texpis]

Is there nothing to leak from CH to hot water then?

Mick

 

[namsag]

If it was going to leak it would be the other way domestic to CH not CH to domestic due to different pressures

 

[Texpis]

Thanks for the reply sounds like a leak under the concrete then is there anything that can pinpoint a leak electronicaly?

Mick

 

[tonybhoy]

Easiest way is to pressure test the pipework/rads with the boiler isolated from the pipework ,i.e. temp capped off.

You'll need a pressure gauge connected to the pipework somewhere convenient too.

That should tell you what's what.

 

[Texpis]

Can I run the hot water with the CH circuit isolated/caped off the guy from the gas board said I couldnt it would destroy the boiler?

Mick

 

[baxpoti]

Can I run the hot water with the CH circuit isolated/caped off the guy from the gas board said I couldnt it would destroy the boiler?

Mick

No problem at all

 

[Texpis]

Hi Baxpoti
Thanks for the reply

No problem at all

trying not to be to cheeky are you qualified to give me this reply just dont want to blow up my boiler

Mick