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 would add cleaner but also have a look at any towel rails sometimes they can cause bad corrosion if there cheap

No towel rails. But the system is fully copper 6 years old new build. Had inhibitor in. But never flushed originally. Was drained down recently for new rad valves.

 

[king of pipes]

Have you physically checked the pressure in the system ? it could just be a faulty gauge or partial blockage in the tube , I'd suggest and good hot flush then a chemical clean and mains water flush check then expansion vessel is charged to 0.7 -1 bar add a couple of litres of quality inhibitor before filling slowly and avoid trapping air in the system even fit manual air vents on high spots if necessary. Kop

 

[Matt0029]

Have you physically checked the pressure in the system ? it could just be a faulty gauge or partial blockage in the tube , I'd suggest and good hot flush then a chemical clean and mains water flush check then expansion vessel is charged to 0.7 -1 bar add a couple of litres of quality inhibitor before filling slowly and avoid trapping air in the system even fit manual air vents on high spots if necessary. Kop

I didn't no, I just bleed the gas/ hydrogen out. Which took the system back down to below one bar.

 

[king of pipes]

Hhmm was there a smell when vented did water come out? test the water there's many Kits available and we should really be doing it . I would say it needs a clean and possibly a new vessel you may possibly get away with not doing it ? , but if you're gonna be there a day why not do it and avoid another trip later your customer only has the one bill then and just gives a bit more peace of mind you've done the job best you can. Kop

 

[Matt0029]

What cleaner would you recommend. I was going to try depressing and recharging the vessel if possible

 

[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