Topping up closed heating system

afatbollix

I had to change a couple of radiators and now need to fill up the system.

I bought a central system filling loop. But my connections to the system are bigger.

Could you give me some advice should I change the filling loop or can I buy a connector or something to connect to it? It says 15mm on the silver filling loop.

I've attached some photos.

NewClareman

I’m not a plumber, but that looks like a connector for a garden hose, like you’d see on a garden tap. You get a screw on connector for the fitting that you can push the hose up onto.

K.Flyer

There is most likely a filling loop on the system somewhere that you haven't located.
The white connection appears to be some type of drain valve.
But if filling it through it is your only option, you need a 3/4" female bsp --- 1/2" compression fitting.
Go to a supplier and ask for a 3/4" female x 1/2" compression 312.
Bring the filing hose to ensure it goes onto the 1/2" end after removing the nut and ring.
Put about four wraps of ptfe tape on the threads of the white valve, screw on the fitting, screw on the filling hose and you're set up.