Sealed system grabbing air

[Matt0029]

Any ideas why a sealed system with a combi could be grabbing air. The upstairs rads have air in and the system reads 3 bar cold. When the air is bleed out the system returns to 1 bar or less. It's an ideal instinct boiler basically a logic.

 

[Matt0029]

I think I have had it before and the expansion vessel read a high pressure when cold/drained

 

[king of pipes]

I like the adey products, the expansion vessel pressure should read 0.7 - 1 bar when drained of water and pumped up . Kop

 

[EvilDrPorkChop]

Fernox, apparently their inhibitor is the only one that's PH neutral (Will gladly be corrected on that one!)

 

[Matt0029]

I like the adey products, the expansion vessel pressure should read 0.7 - 1 bar when drained of water and pumped up . Kop

Thanks the system has had some work on it new trv valves so will of been drained recentlyish. But no cleaner. I was going to try cleaner flush from all drops. And re charge vessel