I have a Smart Thermostat installed called Tado, with a pretty standard UK heating and hot water set up. In my airing cupboard there was a timer that controlled when the hot water and heating was to be on, and down stairs there was a old Honeywell thermostat.

I replaced the timer with a unit from Tado, and bypassed the Honeywell thermostat by crossing 2 of the wires in the actual thermostat so it was always on. That way the new Tado box could control when to turn the heating on or off based on its own wireless thermostat.

This all worked fine, until our decorator removed the Honeywell thermostat, capped of the cables and then boarded, plastered and painted the hole. Now the circuit is no longer complete the heating obviously doesn't work anymore.

Is there anyway for me to do something at the Tado box end in my airing cupboard to complete the circuit again, or am I going to have to tear open the hole in the wall and join the cables again? I have attached some pictures of the wiring below:

This is the thermostat. To make the circuit always on I placed the wire from {3} in to {1}

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This is the Tado Box in the airing cupboard, this is how it currently looks;

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And finally this is the small diagram in the Tado box if it's helpful:

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Is there any configuration of wires I can do at the Tado box end to get the heating back on. Or am I going to have to rip open my wall.

  • Cross posting on multiple sites is generally frowned upon, as it can lead to a mess when questions are migrated. – Tester101 Jun 3 '16 at 18:14
  • @Tester101 I should have closed the other when I posted this one, I realised this was the more appropriate site. The other post has an answer, I'll delete this one... – superphonic Jun 3 '16 at 18:39


Figure 1. Most likely original circuit.

If you were really fortunate the live feed to the thermostat would have originated at the original switch. You could then have connected it directly to your new controller. Judging by the photos there is only one live wire so this isn't the case.


Figure 2. New live feed.


  • Get a new live feed from the original breaker to the controller.
  • Break through the wall and restore the original connection.
  • Try to find the wires above ceiling by lifting floor in the room above or in the attic. Isolate the power, cut the wires and join them together again.

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