Boiler Pressure Loss?

[mbird59]

I have a problem where my boiler keeps losing pressure. I have had a new boiler fitted in the last few months but have/had the problem with both the old and new boilers.

It seems that when I go around and bleed the radiators etc. the problem becomes even worse in so much as when we get up every morning the boiler pressure has dropped to zero. Then over a period of months the problem becomes less acute and we just have to top up the boiler a little every week. I went and bled the radiators again and one particular rad had a LOT of air in it (just as before) which I bled and now we are back with the problem of the boiler pressure dropping to zero.

Is it possible that the radiator that keeps requiring a lot of bleeding could in some way be the problem be causing the pressure problem?

I do not have any water being discharged through the overflow and I have searched high and low but can not find a leak anywhere.

Any help much appreciated.

Michael

 

[twgas]

if you have the same probs with new boiler as old it must be a leak on system somewhere. try removing plastic caps of rad valves to see if there is any weeping through the glands

 

[ChrisR]

YOu shouldn't have to keep bleeding radiators. That points to either micro-leaks or persistent corrosion - probably the latter. Add inhibitor and see if things improve. If not then I'd add leak sealer, but see your boiler instructions about that.

 

[mbird59]

I don't know if this helps in narrowing down the problem but every time the boiler loses pressure and I top it up you can hear a great deal of air being pushed out of the boiler.

 

[mbird59]

Some people have suggested that the pressure vessel might be at fault as the boiler (Vokera) is brand new and as I had the problem on the old boiler is it still likely to be the pressure vessel?

The combi boiler only heats the water for the showers other than this it has a traditional copper cylinder/emersion. I have searched everywhere for a leak is it possible the leak could in some way be in the cylinder?