Automatic bleed valves

Hi Guys N gals

Need some advice. I have fitted a new central heating system, because my house has concrete floors i have run the supply and return pipe in the loft (plastic 22mm) and dropped plastic 15mm pipes down to the radiators. Do i need to fit a auto bleed valve at the highest point of the system and if yes do i need to fit it on both the supply and return or will one do. I have fitted a magna clean type filter which has a bleed screw on it , would this be enough to bleed the air. I am using speed fit fittings.

Cheers

Confused . com

I'd love to see a picture.

But yes. Put auto ones on the top. You'll need to prop them up so that they don't flop over

Is that on the supply and return?

Yes, FLOW & Return. You might only use them for initial fill then close the caps because they tend to leak. After a day or two air should stop collecting.
Use short upstands of pipe to hold some air, away from the circulating water.