I've had a full bathroom instal done however I now have no central heating.....Firstly the overflow valve at the outside of the house was open so when the water was turned on in my tank in the loft it went straight through the full system and all ran out. Subsequently I had air in every single radiator - all radiators have now been bled but my pump is making a straining noise. I have tried to bleed this (while switched on and off) I hear no air being released and there is also no excess water coming out of my pump. When switched on the pump now sounds better but I still have no heating ....There is one radiator I have not bled as the valve is stuck but I don't believe this would affect the whole system....I am unsure what to do now - any help would be greatful.