system design and air problem

[gassafe]

Go to a sealed system...

The air separator is likely to be full of sludge & cold feed sounds like it'll soon be blocked too... That's British Gas for ya

 

[Nobbyone]

I'm getting confused with references to combined vent and fill. Forgive me if I'm misunderstanding the situation but if using the separator the 22mm outlet at the top should rise vertically with the sole function of being the vent pipe and the cold feed from F&E tank connects directly to the 15mm port that tees in, just past the main body.

I thought that if I am going to change the pipework that I would go down the route of doing it using the boiler manufacturers preferred layout which is combined vent and fill but also include the air separator as the tee connection. I am concerned that the air separator does seem to be a good design for a sludge catcher. The pump that is fitted is a Wilo without a vent screw just a setting on the pump which I suspect just pump the air out by reversing the pumping direction. I think that, when it does vent, it is also disturbing and moving sludge around.

I am still confused about the required use of an air separator. Can I remove the air separator completely regardless that my pump is pumping downwards?