Hi all,
house came with this old fancy type of heating and one thermostat stopped working.
I had a spare one of these:
https://www.amazon.co.uk/dp/B00QGKSTD8/ref=pe_27063361_487055811_TE_dp_1
that simply takes three wires - red, black and yellow/green.
But the existing one has 6 wires:
a) one...