Tado V3 upgrade

FoxyChris · 2026-03-14T22:13:34+0000

I was going to replace my current Honeywell BR91 with a Tao v3. The picture is my current working with a live loop to connection A. Can anyone confirm if I’m correct in saying the wiring to the Tado v3 would be the looped wire from L that goes to A would now go to CH COM and B to CH NO?

Many thanks

ericmark · 2026-03-15T00:04:27+0000

A and B replaced with Com and NO, N and L same with both, but there are different versions of Tado. The main reason to swap is often to use the OpenTherm so what boiler and system you have can change how wired.

CountryFan · 2026-03-15T09:07:53+0000

FoxyChris said:
Can anyone confirm if I’m correct in saying the wiring to the Tado v3 would be the looped wire from L that goes to A would now go to CH COM and B to CH NO?

Yes this is correct. If you have opentherm capability on your boiler then it would be better using that, if not go ahead with what you want.

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Tado V3 upgrade

FoxyChris

ericmark

CountryFan

DIYnot Local

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