Low Pressure on Halstead Ace High

[pinheadplanet]

doesnt matter where you leave the drain open but you must leave an open point somewhere, think about it, your EV is full of water , you need to get all the water out, then you can start to pressurise the vessel, you will be surprised how much water comes out before you actually start to pressurise the vessel

So I just keep pumping? How do I know when the water is out of the EV? And then once it's out do I deflate the EV from the Schrader valve again so that I can then fill it to the correct pressure (0.75 bar)? That sounds slightly counterintuitive, if I release the air from the EV doesn't that just get replaced with water from the system again?

 

[Gasguru]

There's a rubber diaphragm inside the vessel...you presurise the air side with the schrader valve. The air pressure forces the diaphragm fully over towards the water side.
Then you re-presurise the boiler side allowing some water back into the vessel. The air side then keeps the system presurised and allows the water side to expand in volume by a few % as the water is heated.

 

[ianmcd]

Once you have completely emptied the water from the EV, no more water will come out of your chosen drain point, then you pressurise the bladder to whatever the correct pressure should be, then close the drain valve and pressurise the water side of the system and you are good to go

 

[pinheadplanet]

Once you have completely emptied the water from the EV, no more water will come out of your chosen drain point, then you pressurise the bladder to whatever the correct pressure should be, then close the drain valve and pressurise the water side of the system and you are good to go

That all makes sense to me, however this is what's happening:\
The water stoped coming from the drain point - fine (I left it open)
I pressurised the EV to the correct Bar - fine
Yet the boiler is showing about 0.4 bar pressure surely this should be at zero shouldn't it? Or is this pressure it is receiving from the EV? Surely with the drain valve still open it should be zero shouldn't it?
Thanks

 

[ianmcd]

Yes it should be, but these are very cheap parts and not always accurate, possibly just a bit of system dirt, wouldnt worry too much

 

[pinheadplanet]

Gentlemen thank you very much. I've had the heating on for 45 minutes or more and it's come to the point where it has switched itself off automatically as it's up to heat and the pressure has not gone over 1.5 bar at any point. Before it would have gone up to/over 2.6.

I'll do another bleed of the rads all round the house later once it's cooled off and top up if necc but looking promising at the moment.
Thanks