Pressure loss in Heating System post fitting new Expansion Tank

[Hoppers]

Thanks for the advice John, very much appreciated. I will let you know how I get on tomorrow. Wife will kill me if I shut down the heating tonight and besides system will no doubt de pressurise itself overnight. Thanks ag

What pressure were/have you been you filling the system to after checking the pre charge at 24psi??.

Just above 1 bar

 

[John.g]

Hopefully, that's the reason for rapid de pressurization, if you wish, you can increase the pressure right now by say 0.5bar (hot) but not > 2.2/2.4bar and see what the pressure is cold in the morning, you can then (should) reset the pre charge/filling pressures tomorrow at your convenience when cold by depressurizing the water side, reduce the pre charge pressure to 1 bar and refill to 1.5bar.

 

[Hoppers]

Just above 1 bar

any mileage in renewing the AAV while I am at it?

 

[John.g]

I don't think so Alvin except that its leaking water, I actually prefer to see a slight leak as you know that the nozzle is clear and generally you can just screw shut the cap on top.

 

[Hoppers]

any mileage in renewing the AAV while I am at it?

I have just topped up to 2 bar as advised and will see how things are tomorrow. I will then do as advised. Thanks

 

[John.g]

Very good, anyway, if you have a leak somewhere, you will see that 2 bar pressure falling well before the night is out.

 

[Hoppers]

I have just topped up to 2 bar as advised and will see how things are tomorrow. I will then do as advised. Thanks

Got it, thanks John. Mind you my AAV has been missing its cap for many years now. A little fluff has gathered inside but I have cleared that out.

 

[John.g]

I don't like AAV's as, unless they are passing water, you don't know whether they are choked or not which easily happens, you might be able to pick up a manual type of if you prefer the automatic type then maybe renew it if it isn't or hasn't been dribbling the odd drop of water.

 

[Hoppers]

I don't like AAV's as, unless they are passing water, you don't know whether they are choked or not which easily happens, you might be able to pick up a manual type of if you prefer the automatic type then maybe renew it if it isn't or hasn't been dribbling the odd drop of water.

John, I don’t think I have ever seen any water dribbling from the AAV. I get a squirt of water when I depress the valve on top?

 

[John.g]

A AAV has got nothing to depress on the top to my knowledge, I have cleared them out with one of my sewing needles by sticking it down through the nozzle, can you post a photo?,

 

[Hoppers]

A AAV has got nothing to depress on the top to my knowledge, I have cleared them out with one of my sewing needles by sticking it down through the nozzle, can you post a photo?,

 

[Hoppers]

I depressed the white plastic insert and water squirted out. I was attempting to lower pressure when I first started to work out why I was losing pressure