Installation wiring query

Just installing my new tado, and I've got a bit of a query regarding the wiring of the receiver.

My existing unit is a salus ep101 which, other than the normal L/N and earth wires, has 2 other wires going into slots 3 & 4

3 = switched live (output)
4 = 230v link from mains live

All five wired come from 1 cablezl, which I'm guessing goes off the boiler, boiler is (oil)grant vortex combo 21e

My question is where do these 2 connections go on the tado unit.

I think (lol) that:

3 goes to CH NO
4 goes to CH COM

Just checking before I dive in 😁

Any other questions, fire away


  • Totalnovice
    edited October 2022
    Hi did you get anywhere with this? I have the same boiler (grant vortex) & programmer/receiver (Salus EP101). I was hoping to just replace my wired thermostat (salus RT300) with the Tado wired smart thermostat so I can control/programme the heating using the Tado going forwards (leaving the receiver ‘always on’ - as I’ve done). However, despite replacing the themostat with the Tado wired one the system doesn’t seem to communicate with the receiver/boiler - so no heating control… or heating at all for the moment… any idea on what might be causing this?
  • Hi did you resolve the wires…that may explain where I have gone wrong. I have wired my 4 up to cH oN