I've got an injector, don't know if it works, but if it doesn't I'll either make it work or get another one. My patent way of filling the boiler is to connect the mains water to the injector overflow, or the pump suction. Then open main stop valve to let the air out. Much easier than pumping away furiously.
Hand pump is just for that panic moment when the water is low and the injector packs up.
Edited By duncan webster on 01/07/2023 19:50:21