Air in Aqualisa 3 bar shower pump

[ShaneCummins]

Hello All, I hope you can help me.

I have an Aqualisa 3 bar power shower pump which has been giving me an issue for some years now.

There is an air lock in hot side of the pump, which clears after continuous running. When it was first installed the hot was connected by a t-piece from the top of the tank which I afterwards discovered was not the way Aqualisa advised.

After many plumbers and many theories, most disagreeing with Aqualisa, I fitted an essex flange with an angled pipe reaching up to the top of the tank and to my joy, problem solved.........jubilation short lived though, after about two weeks the problem returned only this time it is worse.

Originally it took about a minute for the hot to clear now it takes three to four minutes and when it does, It is perfect and very little difference in pressure between hot and cold.

It is a case of venting the pump? if so how would I do this?

Some additional information:

Independent 3/4 feed direct from cold tank in attic
3/4 feed direct to pump from tank via essex flange
Hot water feet at least I metre above pump.

Any advise is most appreciated,
Thank you in advance,
Shane.

 

[HERTS P&D]

I done this for a customer last week.

1. Take off shower head
2. Stick shower hose into a wet vacuum
3. Turn on shower, hot water side only.
4. Turn on wet vacuum.

The wet vac will suck out all the air within 20 sec.

5. Turn off shower and wet vac
6. Replace shower head and turn on shower when shower head is low down in the bath.

Job Done

Andy