Converting To Sealed System - How To Purge Air When Refilling?

[plumbandplumber]

I'm toying with the idea of changing my vented system to sealed. I'm OK with what needs to be done, apart from one thing. At present, when refilling, obviously air is driven up and out of the vent.

If I seal the system, is it normal to fit an automatic air vent on a high point? The boiler has no way of releasing air.

Many thanks.

 

[IDCHAPPY]

Yes, stick a pair of AAV's on the highest point of the flow and return 🙂

 

[Centralheatking]

Why ? CHking

 

[thompsonbrown]

Once its filled and working, I dont see the need to allow for air.
What boiler do you have?

 

[AWheating]

auto air vent by the pump if you want one, no need for one on the system. a thumb vent would be fine.

 

[Ermintrude]

Or don't fully solder joints ?

 

[efficiencyman]

auto air vent by the pump if you want one, no need for one on the system. a thumb vent would be fine.

I`m thinking of doing a sealed system but it has an air eject unit on the flow. Would it be a case of chopping the expansion/vent pipe and fitting the air vent (one option) as above ? Obviously with an expansion vessel for the new condensing system boiler.

 

[Ermintrude]

System boiler might have exp already built in. Fit a jet one , you can remove head and fit new one when pressurised........ Apparently!

 

[mirekone]

I assume you have a ticket to do this? Manual air vent is preferred as AAV sometimes fail and pull in air.

 

[AWheating]

I`m thinking of doing a sealed system but it has an air eject unit on the flow. Would it be a case of chopping the expansion/vent pipe and fitting the air vent (one option) as above ? Obviously with an expansion vessel for the new condensing system boiler.

remove the air seperator from the system, its probably sludged up.

 

[happyflyer]

Or don't fully solder joints ?

Now come on Ermi, that's not the way, use compression and leave all the nuts slack, you can always tighten them when the water comes through the ceiling, no fool like an old fool:crazy:

 

[efficiencyman]

remove the air seperator from the system, its probably sludged up.

There is NO sludge. The reason it was fitted years ago was air locks being a pain. Has worked so well self venting on every occasion when refilling & never had any air locks since. Why remove it when the air separator works so well ?
The sealed system will be manual instead of self venting from the seperator expansion pipe fitted with new thumb screw ?

 

[AWheating]

It's not needed for a sealed system, it will prob sludge up over time if left in. Scrap it.