In the spring when i switched off the heating everything was working ok.All rads working boiler no unusual noises pressure staying steady.
Since then i had a radiator replaced downstairs for a bigger one and an other one added to the system in the kitchen.Some setinel x100 was added.
Now that i have put the heating back on i have had to replace the AAV which is on top of the Expansion Vessel as it was leaking water.Now when i run the hot tap then turn it off ,and when the pump stops i can hear what sounds like water or air going through the boiler or the pipes. After a few days if i bleed upstairs rads i will get air in them all.Checked all pipework and can find no leaks.
Can the pump or any other part let air into the system?
Any help would be appreciated.