Automate old Boiler Burner - suggestions?


Apologize if this topic is off-topic, but I am looking for recommendation from someone who might be an expert OH user.

Problem: I want to “automate” the old boiler/heater burner that my family has in their home…

Complication: the boiler/heater has two main components:

*** Hot Water system which is composed by a tank filled with hot water generated by the burner**

*** Heater System, which is pretty much composed by an Independent water circuit where the hot water is generated by the same burner**

The burner has some old electronics, which is not working that well anymore, therefore, in order to turn on/off the heater, my dad need to switch on/off the “winter switch” on the burner, which pretty much allow the hot water to flow in the heater pipes…

the problem is that all on-board electronics do jot work anymore, therefore there is no way to “regulate” the temperature… the heater is on or off…

my idea is to insert a device (maybe a nodeMCU) and bypass the “winter switcher”… this device should work as follow:

  1. turn on heater
  2. regulate temperature of home

From a device point of view, I think I need something that turn on/off the winter switch, accordingly to two inputs:

  1. you turn on/off the heater
  2. temperature is in “range”

I would love if all I described would be accessible via openHAB…

Does it make sense? any suggestion on how to connect the “dots”?

Many thanks



Is there a diverter valve in the boiler water flow, selecting flow to storage tank, or heating radiators, or perhaps both?

I think you should take a look at my solution. :slight_smile:


You can add a DH22 temperature sensor to it
Flash it with tasmota and follow:

Normally I’d advise to refrain from ‘intruding’ a working control loop, particularly for the heating system.
But as you said your electronics is broken already… I’m doing a similar thing to control my pumps.
Got temperature sensors and OH-controllable valves or thermostats in every room and I turn on the pump(s) whenever there’s a need for heating in any of the rooms that pipe is running through.
Pumps used to be activated by the heater electronics. I have inserted a zwave relay actuator, i.e. heater output now connects into actuator input and actuator output connects to pumps. That way it works when either the heater activates the pumps or I do via OH.
I think you can do the same with your winter switch.
Just remember you won’t want your heating system to fail in case of a OH malfunction, so plan carefully.
If you have an electrical signal cable at the heater’s place that turns ‘high’ in need of heat, you could setup a nodeMCU or Arduino to control that independent of OH, but if not you need OH to work anyway to be aware of a need to heat.
That actuator it’s a Fibaro FGS-222 in my home because I have Z-Wave working, but it could be any SOnOff or anything OH supports …

Purely for safeties sake…

Please… Either get the onboard electronics repaired, or ensure you have a certified fail safe mechanical thermostat in place to shut the boiler down when / if the system water flow temperature exceeds a safe level. ~80°c

Please consider the legal / insurance implications if your software / non-certified solution causes the boiler to break.

That said…

If all you’re doing is creating something that “calls for heat” from the boiler, and the boiler happily regulates the flow temperature, there are plenty of solutions and you’ll get first class support from some amazing people on this forum.


There is definitely something like that, because if the storage tank is “cold” (because I have showered for 3 hours LOL) and I turn on the heater, the priority is for hot water tank first, the the heater system…

Please get a plumber to have a look at it before tinkering with boiler hardware.
You’ll get a safe and accredited insurable heating system.

You can then play with openHAB and control it more effectively than with a simple thermostat if you want.

Thank you everyone…

I have a picture of the boiler… I think that all I need to do is being able to switch on/off the “winter/Summer Switch” based on a temperature prefixed…

is that too simplistic? (this is exactly what my dad is doing manually (on, when is cold… off, when is too hot :P))… he believed that the weekly/daily programming clock (where he used to turn off the heater at night), does not work anymore… and therefore the heater is on or off… that’s it…

Not possible to say from here, really. You’re kind of hoping the water tank, boiler, and heating thermostats are still providing sensible control of the system.

I wonder if the inoperative temperature sensor is the root of the trouble.