Hot Radiators But No Hot Water

[RayGreen]

I Have a balanced flue boiler (an old Thorn M56/76), There has been ketteling sounds in the past.

Tried to flush the system through, this just caused airlocks and did not improve the hot water.

On looking at other DIY sites, Im led to belive that I may need a new Check Valve as the upstairs Rads get on in summer with the heating off!

The upstairs Rads need constant bleeding.

Does this sound like the death of a Central Heating System?

Is there a big fuel saving cost if I replace the boiler with an upto date one?

Any assistance is appreciated.

 

[ollski]

Do you mean an anti gravity valve as you are on gravity hot water?

 

[RayGreen]

I think so. The boiler is down stairs, when it was on hot water only, the upstairs Rads would get hot. I had to switch them off!

 

[RayGreen]

Im on the hunt for the 3 port valve now.....