Swapping out honeywell Sc9420c programmer and wireless thermostat

Wayne67

I'm looking to replace my wired honeywell programmer and it's wireless thermostat Sc9420c
https://www.screwfix.com/p/honeywell-home-sundial-channel-wireless-rf2-pack-2-wireless-timeswitch/73241?kpid=73241&cm_mmc=Google-_-Datafeed-_-Heating%20and%20Plumbing?kpid=KINASEKPID&cm_mmc=Google-_-TOKEN1-_-TOKEN2&gclid=CjwKCAjwp8OpBhAFEiwAG7NaEg5cMz_zEIhuuyEbbC4iCeQSfGQbH9GhZpA6Zb42Vc6nzyl3K1Cu5RoCQKYQAvD_BwE&gclsrc=aw.ds


The programmer has hopefully the standard back box with 4 wires 1 & 2 for power and 4 & 5 control back to the boiler. I've been told due to this it is a simple terminate the wires on the new tado with no other work on the "boiler" wiring box has anyone swapped out the same set up?

Thanks

wateroakley

@Wayne67 This is straightforward for a competent DIYer. We replaced the Honeywell ST9400 with the Tado wireless starter kit. Reach out to Tado support for their wiring instructions. It should be 1-1 wiring and two new links L to COM (CH) and COM (HW).

You'll need to power everything off, remove the Honeywell controller from the backplate and label the wires. Disconnect the wires from the back plate, remove the back plate. Fit the wireless receiver (or wired stat) to the wall, the screw holes aren't in the same place. Reconnect the wires to the Tado box, and add the correct (2) links.

If in any doubt, consult a professional.