Greenstar 28i Water leaking from AAV

[michaelconroy]

After bleeding the radiators the pressure on the boiler dropped below 1 bar. I had to partially refill the boiler. I realised then that water was escaping through the vent hole on the cap of the aav. I tightened the cap to stop the leak. Now I find, when the CH is on, that the water pressure is usually around 2.8 bar, but sometimes exceeds 3 bar.

Does this sound as though I need a new aav?

Should I normally leave the aav open slightly?

Thanks

Mike

 

[Gasguru]

Need expansion vessel re-charging - see FAQs.

Need new AAV...should be left only to allow air venting.

And now due to excessive pressure rise you probably need new pressure relief valve....check the pipe outside for drips. It's a fun job on this pile of carp.

Just a tip for diyers....DON'T bleed radiators unless you know what you're doing.

 

[bengasman]

The whole problem probably started because your system was poorly installed, and equally poorly maintained, which resulted in corrosion.
You should get the system cleaned when there is corrosion, otherwise the same problems will come back.