Baxi Combi boiler losing pressure

[Lloyd Mercer]

Hi,

I have an issue where the combi bolier is losing pressure.
In around 3 hours will go from 2 Bar to less than 1.
If I pressurise the system all appears to work correctly, hot water, central heating etc.

I've isolated the boiler by turning off the feed to Rads and the Hot water and then re-pressurised, the issue still remains so doesn't appear to be a leak in the radiator system.

While the pressure is dropping there is no leak from the Condensate out pipe or the copper over pressure pipe, and no obvious leak from the boiler itself.

Any ideas? surely that amount of water has to be going somewhere, any help appreciated.
In that time frame it must be losing a couple litres of water?

 

[Lloyd Mercer]

Update, when I turn heating back on the pressure jumps quickly to over 3 bar and water comes out over pressure pipe

 

[townfanjon]

Lloyd , you need a GS guy in to check something.
Sorry but its the rules

 

[king of pipes]

GSI needed bud . kop

 

[Lloyd Mercer]

Ok I understand that but in the meantime while waiting and finding someone, can I just I keep filling it up or what? Like I said there is no leak I can see anywhere

 

[Harvest Fields]

Ok I understand that but in the meantime while waiting and finding someone, can I just I keep filling it up or what? Like I said there is no leak I can see anywhere

There is a leak out of what you call an over pressure pipe. Get a gas safe Engineer in. He will fix it for you.