Lots of air in central heating system but pressure not dropping

[alwaysproblems]

Hi All,

I'm aware this has been discussed a lot previously but couldn't find anything exact.

I have a closed loop central heating system. 2 radiators upstairs, one towel and one standard, fill with air frequently. By frequently I mean I have to take the air out once a week. If I leave it for a few weeks it can hiss for several seconds. Strangely the pressure doesn't drop, even when I let the air out. I've bled every radiator and yet the system still gurgles and pops when next used. I've checked every joint thoroughly, even wrapped in tissue paper but can't see any leaks.

When the rads are off and cold they still pop and ping, not a lot but I do notice it, especially at night.

Any ideas what's going on here? Could the system have a build up of sludge? (Radiators cooler at bottom but only noticeable upstairs)

Would it be worth getting a fennox water quality test?

Appreciate any assistance with this.

 

[Madrab]

It may not be air, rather Hydrogen created by excess corrosion. Is the system water dirty?

 

[alwaysproblems]

Cheers madrab. That's what I thought. Will see if I can do the cup / fire test. Water looks clean but it's only what comes out of the bleed valve. System is only 5 years old.

Can I just add inhibitor or should I get the system flushed?

 

[jeff the gasman]

I think your gauge is broken.