Add smart thermostat to Danfoss HIU

[JohnLew]

Hi everyone.
I’ve recently moved to a new building with communal heating and hot water. Inside my flat I have a danfoss unit and a incontro meter/thermostat that works with switch2. Unfortunately the incontro thermostat is not able to connect to WiFi, so I can’t control my heating when I’m away.

I want to add a smart thermostat but keep the incontro smart thermostat working too if possible.

Ideally looking to add something that doesn’t need a hub, just a simple connection to WiFi and a app.
I’ve seen some MOES or Meross on amazon and wondering if they would work.

Below the danfoss unit there’s a junction box that I believe connects the unit itself to the mains, meter and thermostat. The unit only takes 3 wires, brown/blue/earth.

Inside the unit there’s another distribution box that splits the wires to what I believe to be a valve and a water pump.

Anyone could tell me what would be my best option to wire the smart thermostat, if possible at all? I would keep the thermostat next to the junction box so it stays hidden away.

Many thanks in advance

 

[Stuckinarut]

Probably going to need a WiFi switch/relay to keep existing thermostat, otherwise you’ll need a programmable thermostat.

 

[JohnLew]

Found an online wiring diagram for a similar unit to mine. If I wire the thermostat in the junction box as shown in the picture but leave the current one wired am I correct to think the thermostat won’t trigger the heating to start as the current thermostat will be in a off position ?

The wiring will be top one from the picture. The lower diagram is for underfloor heating.

 

[JohnLew]

Think I found how to do it.

The unit works simply with on/off power.

The junction box below where the 3 wires from the unit connects have the live on demand from the thermostat. If I swap the brown to a permanent live the unit comes on. Hope this makes sense.

I need a smart thermostat that works only with 2 wires, just like a switch on off Permanent live going and the power to the unit once the thermostat on. I can get a neutral and hearth if need too.

Anyone with a idea for a thermostat like this ? Thank you.

 

[Stuckinarut]

Plenty of 2 wire thermostats available, have a look at Drayton 2290b