Myson Marathon 80c floor mounted boiler:
To avoid a further stitch up price which a widowed friend of the family recently suffered £840 for 8 bog standard rad valves.
Problem: c/heating tank over flow pushes out water intermintent when boiler on.
the water inlet to the tank is ok it shuts of 2" below overflow. There is a hook shaped pipe about 1" dia over the tank could this be expelling water every so often. I think it's what's termed a 'Vent" pipe looking at central heating diagrams. What would the cause be and what is the solution and rough £'s cost many thanks.