I have increased the water pressure to 1.5bar and slackened off the aav bleed screw and the noise is 90% gone now :)
A final question, does this bleed screw need to be permanantly slackened off? As it was tightened up when found..
Many thanks for all quick responses
Thanks for your reply Gaz. I unscrewed the black plastic screw on top of the aav,some air came out for a while but the noise still remains. I noticed some green gunge on top of the brass aav unit.
How do I tell if the vent needs replacing,can it be removed and cleaned? Do I need to drain down...
I have a 3 year old Baxi 105he instant with a noise problem. After using hot water demand, eg shower, and the water is turned off, the boiler goes into a frenzy of gushing and squelching sounds for about 2-3 minutes. The pressure gauge drops about a third of a bar to .75 while this is happening...