I think the pump is working fine and I think it's full of water, when working is not making any funny noise, I can hear the water running through. By the way how do you bleed the air from the pump? I can't see any bleeding valves on mine
My heating system is a open vent with storage tank upstairs in the bedroom, and boiler in the kitchen. Last week had a leak on a radiator pipe on the hallway, and had to replace the pipe (plastic pipes). After fix the pipe, I bled all the radiators to remove any air on the system. After that...