Hot water in f+e overflow pipe constantly

[John.g]

Can't see how a unbalanced shower mixer can cause any problems for the heating system as it is a completely separate system.

 

[Azza41]

Can't see how a unbalanced shower mixer can cause any problems for the heating system as it is a completely se

Can't see how a unbalanced shower mixer can cause any problems for the heating system as it is a completely separate system.

Im only under the assumption its the f&e tank I'm thinking the cold is pushing the hotvwater up the expansion pipe into the header tank

 

[John.g]

It could possibly push hot water into the cold water storage (CWST) tank but no way into the F&E tank, just establish which tank is overflowing.