Still looking for one of these please, if any of you CH engineers might happen to remove one, whilst swapping to perhaps a combi system...
I have altered my heating system from using a SD 2701 (for which I have a few spare heads), to a system using a Sunvic SDM 1901 three port valve head/ actuator. I am well accustomed to the these heads suffering failures, hence my keeping spares for the 2701 and repairing them as necessary. The 1901 head seems a much better/ more reliable design, hence my changing my system to suit, but being now a little actuator paranoid - I like to have a spare to hand, ready to fit.
So I am now looking for some surplus to needs Sunvic SDM 1901 heads, faulty or working, to repair up as spares please. Obviously I don't want any seriously water damaged, or blasted ones. Happy to pay postage, plus a couple of beer tokens.