Ariston DIA24

[Hypnoman]

When the hot water is being drawn the return on the central heating heats up, therfore heating radiators. Divertor valve has been replaced and all other inernal pipeworkand fittings checked for restrictions. Help please

 

[ChrisR]

I have seen this before but on a differnt combi. That time it was a built-i bypass valve letting water the wrong way, You need a good schematic diagram or thorough understanding of pressure sensing tubes and the like on your particular boiler.
Start with everything cold and draw hot water, then go feeling all the tubes for warmth. Keep the water running, because when you stop the diverter will send hot water round the heating on overrun, which will mask what's going on.

INteresting one - would like to know the outcome on this one!

 

[Hypnoman]

Thanks for the contact, No internal bipass fitted to this model. Any other ideas. It,s the fact that the return is feeding the CHW that I can't get my head round.Would fitting a non return valve in return line be an acceptable solution.
Thanks