Opentherm Thermostat

Forum about Opentherm, Hvac, House heating, Boilers

Moderator: hvxl

Opentherm Thermostat

Postby lifer » Thu Oct 13, 2016 1:55 pm


I thought about building an Opentherm gateway at first but then I realized that it might worth to add some more functionality (by incorporating a temperature sensor and some logic) to act like a standalone thermostat, too.

That's it, by reading the boiler parameters (in gateway mode), I could make use of instant flow/return temperatures and by logging the room temperature versus time (and setpoint / modulation level) I could compute a heating/coo!ing curve for my house.

I want to use an Arduino and a ESP8266 wifi board to get wireless functionality. I could further add various RF sensor nodes for outside and zone temp sensors.

Does anyone built/start such a project, to not reinvent the wheel? I've read and searched a lot but I didn't found anything.

Thanks in advance for any clue.
Starting Member
Starting Member
Posts: 10
Joined: November 2012

Re: Opentherm Thermostat

Postby Rokite66 » Fri Oct 23, 2020 12:02 pm

I am looking for the same thing. I have everything built, connected and working (opentherm gateway connected to boiler and homeseer PC, wireless temperature sensor inside and outside). Also I do not want to reinvent the wheel. What I need is an example of how to combine: inside temperature, requested inside teperature, outside temperature to control the boiler water temperature. I have also looked everywhere but all I can find is that it is not easy and that you need to implement a PID loop. Hope someone can point us in the right direction.
Starting Member
Starting Member
Posts: 2
Joined: October 2020

Return to Hvac, Heating Opentherm Forum

Who is online

Users browsing this forum: No registered users and 1 guest