Opentherm on 2 zones

I have a Potterton Promax Ultracombi 33 fitted with IFOS kit and 2 wired Tado thermostat (currently connected using relay on/off). The Tado thermostat offers weather and load compensation.
Boilers and thermostats support opentherm connection, which I tempted to go with, but wondering if the Tado will override the IFO kit or still possible to set the curve as usual.

I would be very grateful if you could share any insight you may have with similar setup.


  • johnnyp78
    johnnyp78 ✭✭✭
    You can’t usually use opentherm on a multi zone house because your Tado thermostats will be wired to the zone valves, which require a relay connection to open and close, rather than the boiler. I don’t know what ifos is though.
  • Montage
    Montage ✭✭✭

    IFOS is a weather (temp) sensor.

  • johnnyp78
    johnnyp78 ✭✭✭
    In that case probably best to stick with that.