Central Heating-Air Getting in and Water Getting Out

Bob_Kirkham

We have a sealed heating system in our bungalow consisting of a gas fired boiler and a Flexcon expansion Vessel and are suffering from air getting in and water getting out.

The bathroom radiator collects any air in the system and now needs needs bleeding every 2-3 days, the pressure in the system also drops from 1 bar to 0 in the same period.

The problem is there is no sign of any leaks, I have put a container under the expansion pipe from the expansion vessel and there is no discharge and I have chacked the majority of the pipework for leaks, a mixture of 1960's copper in the old part and HP20 in the extension, about 4 years old and no sign of anything.

I have been told it could be the expansion vessel needing to be recharged to equal the pressure.

I am fairly practical but this has been going on for about 12 weeks and has got worse to the current position. Any help would be most gratefully recieved.

Bob

Canucklehead

Hi


You might find it's not air getting in but the product of corrosion, hydrogen.
As you say the expansion vessel discharge pipe is dry the I would say it's ok and doesn't need charging up.If you want to check it then wait until all the pressure is gone, then check to see if it's about 3/4 of a bar 14 psi .You need to have somewhere on the system open to allow the pressure to escape when pumping up or you'll get a false pressure reading.Do not use the pressure relief valve as an means of draining.
If you have suspended floors (floorboards) I would start taking some up and see if you can find a leak.Maybe start where the new pipework was connected into the old.
If you have solid floors then is the pipework in the roof? Do you have auto air vents up there .They will allow air in as well as out.
The longer you keep filling with fresh water the more the system will suffer from corrosion.It might need to be flushed through and definitely inhibitor added.

Corgi Guy.