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Topic: Open communication, thermal actuator (Read 493 times) previous topic - next topic


Dear community

I am doing my own home automation project and the first thing I want to do is to place a temperature sensor in a D1 mini, that will control the heater of each room.

So, I need an "electronically controllable hand" that opens the valve of the heaters of my house (hot-water based radiators).

The first thing i thought is to have a relay in the D1 mini that  controls a dummy thermal actuator (an electric valve that you just put in the radiator instead of the manually handled valve)that opens/closes the heater valve, i.e.


However, i see two issues here

1) This home-made device could put me in a trouble if something goes wrong and there is a fire. (Yes, I know that this is not likely to happen but ... )

2) As far as I see, with those relay-controlled thermal actuators, you can only fully-open fully close the radiator, and I am not sure if this is the most efficient way to heat. Of course, I could do a kind of PWM, but the first point really scares me.

So, I was considering something like this:


Long history short, this is also an electronic valve that you put in the valve of the radiator, but 1) Is not just a dummy device that either opens either closes the valve, it can open the valve some "degrees") 2) it has batteries, which helps with the consumption.

Where is the issue with the latter one? Well, in order to use it, you will need the danfoss bridge, the danfoss app ... so it is a little bit closed for what I want.

Now we reach my question:

Does anybody know a valve like the latter one, with open communication protocol? The D1 has a built-in wi-fi, so I could use that. Maybe I could just use a shield for other communication protocols.


Nov 14, 2017, 10:08 pm Last Edit: Nov 15, 2017, 06:30 am by jremington
It seems likely that there is an off-the-shelf electric valve that fits the radiator, which you could control with an Arduino. But if not, you could cut the input or output water pipe and add one.

Otherwise, reverse engineer the protocol for the expensive Danfoss unit.

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