Help replacing old thermostat with new

4 Oct 2020
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United Kingdom
Hi I have a new thermostat for our central heating which I'd like to install, however I'd like some guidance on wiring it in.

I have some experience in electrical work, and have taken precautions to isolate the wiring, and checked with my multimeter, so everything is safe to work with.


This is the old thermostat and wiring.


This is the new one, and instructions. I assume the existing live and neutral go to pins 7 and 8 as shown, but then does the control wire go to one of 3 and 4?

Thanks for your time.
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