L wire into com connector

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I’m trying to replace an ESI wired thermostat with a tado wired thermostat.

There were three wires going to the back of the ES I thermostat, N, L, and NO.

On the tado installation guide it tells me to put the NO into the NO connector and put the L into the COM connector and to put the N into the P1 connector, having spoke to a plumber friend of mine he told me not to put the L wire in the com connector as that would just push power back into the boiler and blow it up can anyone help me work out how to install tado with these three wires please, thanks

Answers

  • Hi,

    The Tado instructions are correct. COM is simply the common point of the switch in the stat. This is then switched between two outputs NC (normally closed) and NO (normally open).

    The N cable is unused so is just parked in the P1 connector.

    You old stat will not have been using the cable in the N connector either and did not have that NC side of the switch exposed to a connector as it was not needed.

    Gabriel