Sealing an open vented system

[lordyjordy111]

Hi lads....

Had a customer last week with an open vented system. system was sludged a few of the rads downstairs not working well at all.

anyway, powerflushed system and installed new pump which helped but still the rads downstairs where not working great.

the guy that I worked for told me to seal the system which i did. The rads downstairs now work a treat!

Cant get my head around why though? and my boss is quite vague in his explanation.

anyone know the reason why sealing it up has helped... do you guys seal open vented systems in similar situations

let me know

cheers

 

[Ermintrude]

Vertical drops on microbore . It's probably higher pressure drop through rads than it is to the headder so system ends up pumping over. Can't pump over on a sealed system

 

[lordyjordy111]

thanks for the reply...

problem is it wasn't a microbore system it was 22mm and 15mm copper?

 

[Ermintrude]

Air lock

 

[zzzjim]

Pump speed ? ( flushed out air lock on poor layout ?)


( but I don't convert -as need to know all safety issues )

 

[kris]

Might be that system worked mediocre for years (not to full potential) then someones maybe added something or sludge sttarts to fill system due to poor circulation and position of the cold feed and vent pipe , so by sealing them off theres either no air been drawn in down the open vent causing air locks ( which can be the cause when folks think its sludge) and thus allowing the pump to work with out restriction,

 

[stevetheplumber]

unless it was pumping over previously i cant see how sealing it could make any diffence other than a higher filling presure which could shift an air loc,k pump presure and flow rate will not change

 

[PhoenixServices]

If there is nothing in the screed then I seal it. But usually if I seal a system with pipework in the screed it either shows up a leak or creates one.

 

[Nishikigoi]

We spend all day every day from now to Easter finding leaks and the most common customer comment is:

"We had a new boiler and now it's a pressurised system"

30 year old plumbing + Powerflush + Pressurised to 2bar = Leaks

By then some bright spark has tried to stop a 12 hour leak with a couple of cans of leak seal and we're having a proper game when the trace gas sets it like concrete!

Rant over....nurse!!