Connection of modulating thermostat to boiler

canacchione
Posts: 21
Joined: 21 Sep 2022, 09:08

Re: Connection of modulating thermostat to boiler

Post by canacchione »

I hadn't read this anywhere. So in no way can the smart thermostat be connected to the classic two wires coming from the boiler even if connected on position 3-4 (opentherm) if not only through the relay ... which in turn will be fed. I ask you because in my case the boiler is positioned in a technical compartment but outside the apartment so if you placed it externally there would be the risk that it would not be able to communicate with all the solenoid valves placed on each radiator, even the most distant. So I will take advantage of the wires coming from the boiler up to the current position (in the center of the apartment), connect the relay and bring two wires to feed it. Only in this way will I be able to be sure that the relay will be able to communicate with all the solenoid valves of each radiator and with the modulating thermostat
sergeantd83
Posts: 84
Joined: 12 Nov 2020, 13:21

Re: Connection of modulating thermostat to boiler

Post by sergeantd83 »

It looks the optimal solution for your installation.
MarcV
Posts: 880
Joined: 22 Aug 2016, 09:01
Location: Schoten, Belgium

Re: Connection of modulating thermostat to boiler

Post by MarcV »

canacchione wrote: 30 Sep 2022, 08:46 I hadn't read this anywhere. So in no way can the smart thermostat be connected to the classic two wires coming from the boiler even if connected on position 3-4 (opentherm) if not only through the relay ... which in turn will be fed. I ask you because in my case the boiler is positioned in a technical compartment but outside the apartment so if you placed it externally there would be the risk that it would not be able to communicate with all the solenoid valves placed on each radiator, even the most distant. So I will take advantage of the wires coming from the boiler up to the current position (in the center of the apartment), connect the relay and bring two wires to feed it. Only in this way will I be able to be sure that the relay will be able to communicate with all the solenoid valves of each radiator and with the modulating thermostat
That will be my problem also...
...but I might be wrong...
GEORGzer
Posts: 2663
Joined: 14 Jan 2014, 18:14

Re: Connection of modulating thermostat to boiler

Post by GEORGzer »

Now that I had time to think about it, it makes sense that only the Relais can communicate with a data signal. For that, the Thermostat would need a wired power option and probably wifi onboard as well.
Home: Weather Station (V3 + Rain & Wind Gauge, 3 additional Indoor Modules, Shield), Valves Starter Pack + 7 Valves, Video Doorbell
Office: Thermostat (V2), Healthy Home Coach, Smoke Alarm, 2 2in1 Sensors

Not a Netatmo employee
sergeantd83
Posts: 84
Joined: 12 Nov 2020, 13:21

Re: Connection of modulating thermostat to boiler

Post by sergeantd83 »

Theoretically The thermostat can be an OpenTherm controller because OpenTherm supports “smart power” ( The boiler is able to feed with power the thermostat with the OpenTherm terminals, but don’t know if it is sufficient to support the wireless functions of the thermostat ). Moreover it wouldn’t be so easy to have 2 different OpenTherm controllers ( both Thermostat and relay ), the cost would be much higher and not all the boilers support this feature, actually there is not such a device in the market.
GEORGzer
Posts: 2663
Joined: 14 Jan 2014, 18:14

Re: Connection of modulating thermostat to boiler

Post by GEORGzer »

I personally always recommend to wire the Relais to the boiler anyways, only exception if it would be out of wifi range.
Home: Weather Station (V3 + Rain & Wind Gauge, 3 additional Indoor Modules, Shield), Valves Starter Pack + 7 Valves, Video Doorbell
Office: Thermostat (V2), Healthy Home Coach, Smoke Alarm, 2 2in1 Sensors

Not a Netatmo employee
sergeantd83
Posts: 84
Joined: 12 Nov 2020, 13:21

Re: Connection of modulating thermostat to boiler

Post by sergeantd83 »

I totally agree. This is the best practice especially if your home is equipped with the smart valves.
canacchione
Posts: 21
Joined: 21 Sep 2022, 09:08

Re: Connection of modulating thermostat to boiler

Post by canacchione »

GEORGzer wrote: 30 Sep 2022, 18:57 I personally always recommend to wire the Relais to the boiler anyways, only exception if it would be out of wifi range.
Do you mean both the opentherm connection and the relay power supply?? All coming only from the boiler??
GEORGzer
Posts: 2663
Joined: 14 Jan 2014, 18:14

Re: Connection of modulating thermostat to boiler

Post by GEORGzer »

Yes. You add the Relais brown and blue wires to the boiler‘s power supply and connect the grey and black wires to the OpenTherm terminals.
You can also mount an ordinary power plug to the Relais if you prefer that and a socket is nearby.
Home: Weather Station (V3 + Rain & Wind Gauge, 3 additional Indoor Modules, Shield), Valves Starter Pack + 7 Valves, Video Doorbell
Office: Thermostat (V2), Healthy Home Coach, Smoke Alarm, 2 2in1 Sensors

Not a Netatmo employee
canacchione
Posts: 21
Joined: 21 Sep 2022, 09:08

Re: Connection of modulating thermostat to boiler

Post by canacchione »

GEORGzer wrote: 03 Oct 2022, 11:50 Yes. You add the Relais brown and blue wires to the boiler‘s power supply and connect the grey and black wires to the OpenTherm terminals.
You can also mount an ordinary power plug to the Relais if you prefer that and a socket is nearby.
so in my case that I only get the 2 opentherm wires in the central point of the house, it would be better if I sent two more wires from the central point to the boiler to power directly to her, instead of connecting to two current wires anywhere, right?
Post Reply

Return to “General Questions”