Final Couple Of Exp. Vesel Questions.

[youdontwanttodoitlikethat]

My ongoing saga with Turbomax, and blown ev. I'm piping up a new external (Reflex brand/Screwfix) ev to the boiler tomorrow as a replacement on the return pipe.

1) The new ev is 12 litres and precharged at 1.5bar, the Vaillant's is 10 litres - charge should be .75bar. Is it OK to let pressure on new ev down to .75bar?

2) The new ev's instructions says it's prefilled with nitrogen. If I need to top up in future, can I just put air in?

Thanks to all.

Fred

 

[youdontwanttodoitlikethat]

Ok, before anyone got to me, I've successfully installed the new external 12ltr ev, and everything seems fine.

2 more questions in addition to the ones above;

I took the risk, and reduced the new ev's pressure to .75 bar. With the heating on, and boiler's radiator dial set to three quarters, the boiler's pressure stays the same as when cold. It's pressurised to 1.2 bar cold, and stays at that even when fully up to temp. Is this OK?

Do I need to bleed the Turbomax's pump following drain down and refill?

Many thanks

Fred.

P.S. No more questions.

 

[telegan]

i would have left ev at supplied press , yes you top up press with air from a car foot pump
listen to the pump it will cavitate if full of air and be quite noisey. the air in theory should go to the highest point in the system- keep us posted

 

[The831Bunny]

Did you cap off the old vessel? Good chance it will leak on the seam if you don't isolate it.

Personally I'd have the vessel charge at 1Bar, adjust the system pressure to 1.5 Bar cold, and on a 12L vessel you should get no more than 0.2 Bar rise on a typical 8/10 rad system. Jobs a goodin'

 

[youdontwanttodoitlikethat]

Thanks for your replies.

TELEGAN
Pump was slightly noisier for first few mins after start up following work. Fine now. Doesn't seem to trap air like pumps on vented systems.

831BUNNY
No, didn't cap old vessel. I saw the joint for it, behind control panel and dhw plate HE at the back. Is this 15mm compression, can I just put a comp cap on it? I might just leave it until it leaks. Hopefully it will be a pin hole, not a sunami over the electrics.
Will top ev pressure up a bit. Only a small system, 1 x long double, 3 x medium singles and a small single rad in bathroom.

Since new vessel has been plumbed in, PRV seems to be holding - one less thing to buy!