Air being drawn into system after removal of back boiler

[Golfball]

Hi guys

I moved into a bungalow and recently removed the hearth,fireplace and back boiler

The back boiler used 3 tappings

The top tap is the flow to the cylinder
The bottom 2 are the heating flow and return

To give me heat and water I connected the 2 flows but now there is a massive amont of air being drawn into the system - at the start of every day I could bleed the 2 rads first on the system almost completely

I reckon it is coming in through the open vent at the header tank

So

1. am I right

2. Can I put an automatic air vent on the open vent(problem being I don't know if these allow steam out in case anything did ever overheat at the cylinder but it would cure the intake of air surely ?)

Many thanks for any help

 

[kevplumb]

To give me heat and water I connected the 2 flows

to what ????????????????

 

[Golfball]

I linked the flows

 

[kevplumb]

The top tap is the flow to the cylinder
The bottom 2 are the heating flow and return

now i might be wrong but your one adrift there

 

[Golfball]

The return is capped off at the injector tee