What is the max amp of water demand signal

So if I wired the water demand output in the controller to a tank hot water thermostat controlling a valve (my hot water is gravity cycle to a tank) what is power output of this hot water trigger. Will it blow the receiver by drawing too much when the valve operates?


  • Tado can switch a maximum of 3 Amps.

  • davidlyall
    davidlyall ✭✭✭

    I *think* your valve should have it's own power supply so the current draw through the Tado is only telling the valve to move and not actually moving it. Certainly, that's how my S-plan system works using Honeywell valves

  • Thanks i will check out wiring although I thought that the thermostat just switched live to the valve head controlling a one way valve to allow a gravity feed from boiler. Maybe not since old control wire from boiler on different phase to power feed to valve so just a bit wary, hence thought to just power all from boiler.
  • GrilledCheese2
    GrilledCheese2 ✭✭✭
    edited June 8

    @Snowdon the full current required to energise the valve's motor will flow through the thermostat. The motor will have a permanent neutral, but the live is switched. The current is relatively low at about 0.04A, so well within the capacity of the thermostat. Not all installations are standard, so if you have any doubt you should really consult a qualified electrician.

  • Thanks. This is as I thought and plan was to just feed live from the hot water terminal in tado to gain timing control and switched through the tank thermostat to valve. It is an odd and old oil system with gravity feed through to cylinder heater circuit. But unlike modern boilers will probably go on for another 20 years!