Air sucked in system

[gas4you]

The only 2 options I can think of are;

1) change cold feed to 22mm and let it t in to top of 28mm, making a 'H' shape.

2) Fit a 28mm aerjec or similar.

Theory states that the cold feed should hold around 3% of the system volume.

Pump should be as close as possible to the aerjec or 'H' arrangement.

 

[Dan Robinson]

Why don't you seal the systems? Or have I missed something?

 

[giblets]

Why don't you seal the systems? Or have I missed something?

That's the job for next week.

 

[Dan Robinson]

 

[chrishutt]

When the rad circuit comes on the level in the feed tank drops by about 10mm. When the rad circuit is turned off (and pump stops) the level in the feed tank returns to normal but a quantity of water is expelled from the vent pipe into the feed tank.

That can be explained by there being a large volume of air trapped in one or more of the radiators. When the pump comes on this air is compressed by the higher pressure allowing the feed tank water level to drop. When the pump shuts off the air expands again and pushes the feed tank level back up.

The air may be entering upstream of the pump after the feed and expansion connection (neutral point), particularly if there is a blockage (e.g. between pump and neutral point) upsetting the normal pressure gradient. Air will enter if there is potential air leak and the negative pressure generated by the pump is greater than the static pressure, so generating sub-atmospheric pressure. The general principle of pumped circulation is illustrated by this diagram.

 

[bobby_la_mesma]

Guys

Thanks for all the help. Combining the Vent and cold feed has solved all my problems. Thanks Agile. What a super star you are!

Rob