The Ultimate home furnace/heater controller

Hi All,

Well maybe I don’t have the “ultimate” in heater/furnace controllers but I have not seen anything else like this for Home Assistant. Just a note from now on I will be calling it just a heating controller not a furnace/heater.

Parts Used
2 ESP8266’s/NodeMCU’s
4 way relay board
old scavenged Sonoff relay
2 USB power supplies
Old wall mounted iPhone 5
Car magnetic ball mount thing
3 Xiaomi temp and humidity sensors
Header Wires
Soldering stuff
Misc wire

My idea was to have my heater to be controlled by Home Assistant with individual temperature controls for each room/zone, My home has 24v electric dampers installed in the forced air system which gives me 4 “zones”. I wanted to do this since I always find my downstairs area very cold and the upstairs area hot or different zones too hot or cold. I wanted to keep the original switches on the wall so anyone could control the system without using a phone. I also wanted to have a touch screen interface to replace the old heater controller on the wall this is where the iPhone 5 comes in. I enables the homekit componentand used a magnet car mount to stick the phone to the wall.

How it works The Heater
Ok so this may become complicated but I will try and explain it very simply. First at the heater itself I have a ESP8266 running Tasmota this is where I use the Sonoff relay to connect or disconnect the two heater control wires together. Also running off this ESP is a AM2301 temp and humidity sensor this is placed in the return air duct to give me a temperature reading for one of my zones. Here are some pictures of the heater side

The red and black wires are the ones being connected and disconnected.
This is inside the project box the JST red connector goes to those two red and black wires and the 3 pin connector goes to the AM2301
Here’s the wiring diagram for my heater if anyone is interested. Its a Breamar TX420 if your interested.

So far all I currently have is a heater controlled by Tasmota which is great but I want to control the zones next.

How it works The zones
Ok so the zones are a little more complicated. Behind the original manual switches I have
installed a 4 way relay board and another ESP8266. The relay board has NO and NC contacts it is setup in a way that when power a relay the zone turns OFF when power is taken away the zone turns ON. This ESP is also running Tasmota to which i have connected the original wall plate to allowing manual control. To power the ESP I cut the end of an extension cord and got my father who is an electrician to connect it to the back of a nearby light switch. This then has a USB power supply inside the wall plugged into the cord then powering the relay board and the ESP.
Here are some pictures.

The back of the old manual switch’s. (I live in Australia so our switches are quite small allowing us to fir up to 8 switches in one switch plate. Simmiliar size to US switch plate size’s.)
Here is the whole system relay’s, switches and ESP.

The wall controller
On the wall I used a magnet to stick an old iPhone 5 to it running Apple HomeKit. This is then linked to Home Assistant allow individual control of each zone.

The controller on the wall.

Inside Home Assistant
image This is what is inside the forontend it is simple but works well. Each thermostat is a Generic Thermostat toggling Input Boolean’s which an automation then monitors switching on the main heater and then the corresponding zone. It then does the opposite to turn off the zone their is some more complex automation to go with it. If people would like to see the automations in more detail I can post them.

Well that was a long post! I hope I have explained my system well and someone can either use my idea or modify it for their use.


Hey Riley. Love the project and exactly what I want to do in my place. Could you share your code and automations by chance?

Hey Mate,

There isn’t much code to speak of. It was all done with Tasmota and Automations. I am happy to send you to them when I get home from work.

That would be great if you could send the automations!

Thanks very much.