(under) pressure question

[OliF]

I was wondering if anyone can help.
I have a multitherm electric boiler in a sealed system. We recently had a blow out and had to replace the heating element, thermostat controller in the boiler and the pressure guage. Once the system had been turned on again and the pressure set to 1bar cold everything seemed to be fine. But through the evening the pressure in the system dropped. When hot it never goes above 1 bar and when cold is slowly drops to now just under 0.5 bar. I can feel that at least one of the radiators has air in it. Could this be the problem? and if so should I just re-pressurize and bleed the radiators till I get the system to 1bar cold?

I don't know if this is just part of the system settling down again or if it is something else. I can see no leaks and am not sure where the air may be getting in.

Many thanks for any help you may be able to give.

 

[ChrisR]

Surely it HAS to be leaking? Is there any sign of the pressure relief pipe having let any water out? ( Put some dry tissue in the end and leave it there)

 

[OliF]

Not seen any water leaking but will try the paper thing.

Don't mean to sound dumb but you do mean the pressure relief thing that's with the pressure guage? We had to have a new one fitted when the boiler was fixed as the steam and hot water melted the last one when it went tits up.

Oli

 

[OliF]

Nice one!! Found the leak and got a mate with a blowtorch to come round. We soldered the join and flushed out the air in tehy system that was causing the original problem.

Many thanks for your help Chris.