Air Separator or combined unit ?

[goateater]

Do I get an air separator or a combined deaerator and dirt remover ?

I was looking at the Spirovent 28mm, but spiro don’t do a combined 28mm unit

I don’t want the plastic bottle unit

Whenever I drain/refil the system I always get air trapped, it takes ages for it to clear

And now I’ve started reading about air separators I wonder if I should get a combined deaerator & dirt remover

Do I get a 28mm combined unit and fit it near the boiler or get the Spirocombi 22mm and fit it to pipework in air cupboard ?

Any advice is welcome


I have an F&E system with oil boiler and pump by the boiler,

28mm pipework up to the airing cupboard where it splits into 3 circuits

1, hot water tank indirect

2, upstairs radiators

3, downstairs radiators

There are 2 air vents fitted on the pipework in the airing cupboard