Wifi control of a electric heater

Hello everyone,

I have no experience with arduino, so I might be making some wrong assuptions, please excuse me for that.

My goal is to automate one of my electric heaters, a Atlantic Maradja. I want to do it remotely, e.g. controlling an arduino through (some commands sent by) wifi.

The heater has a feature that might help this: it has an extra electric wire through which one can send commands. Most commands are simply coded through connecting the wire (230V) permanently, or during some seconds, which seems quite simple to do, maybe using a wifi relais. A general description of these commands can be seen in the picture below. (Sorry, I cropped it from the english manual, but the text is still in french, hope you can still understand it) Confort, Eco, Hors Gel and Arret Chaufage are the different operating modes.


The problem are the two last orders, where one needs to send either only the negative or the positive part of the current. This is what I don't know how to do.

Is this easily done using some arduino and eventually some accessories? Could someone point to some interesting projects that might help me with this? Any help is more than welcome!

Thanks and best regards, Luís

PS: The full manual, also in english, can be seen here: Redirecting to https://docgaproduction.cellar.services.clever-cloud.com/documents_a6576a01-c764-4cf5-ba24-d723c91e8a4a/user-manual-maradja-smart-pilot-io.pdf?AWSAccessKeyId=MW2NM1KMBUFH2SMVHW1L&Expires=1622405272&Signature=W4uMF4E23at8sL4IXKYXFybpMOM%3D

First, your link is badly formed.
Second, the manual shows no wiring diagram, so I doubt anyone is going to risk advising you how to use the "pilot wire" to control the heater.
Third, and this is the reason that you probably shouldn't be taking this project on, the last two waveforms are what you get when you pass an AC signal through a diode.

There is also no scale to the "oscilloscope" drawings. I can't tell what the time base is or the voltage represented.

Why don't you just buy their WiFi bridge?

the link did not work for me.

Atlantic Maradja has a site and on that site, they offer remote control with a smartphone.

we deal with the hobby side of electricity. once you start with mains voltage, we have a belief that if you have to ask, it may be too difficult for your.
if you do not understand, then you do hire someone that does.
mains voltage can kill and we want people to be around for a long time.

the way I interpret the signals.
no signal means local control.

#2) is that you provide a 3 second pulse every 5 minutes to run at 1 deg less,
#3) a 7 second pulse to run at 2 degrees less.
#4) connected to 240 = ECO, but that does not mean anything.
the last two.... well ...we would need to see the manual for that.

if there is a device that you can buy that connects to the heater to receive WiFi commands, then that is your missing part. Get that and then sending the signals to that should be something we can help with.

plain heater power control with Triac GitHub - jandrassy/Regulator: DIY Arduino consumption regulator build to use excess solar power for auxiliary 'summer' heating. The solar power data are retrieved over SunSpec Modbus TCP. IoT monitoring with Blynk and local Web server.

This link works for me: Redirecting to https://docgaproduction.cellar.services.clever-cloud.com/documents_a6576a01-c764-4cf5-ba24-d723c91e8a4a/user-manual-maradja-smart-pilot-io.pdf?AWSAccessKeyId=MW2NM1KMBUFH2SMVHW1L&Expires=1618585711&Signature=BqAwgybPWtefwc2428rFUL20m50%3D

I guess the last 2 commands, Frost Protection and Heating Off, are obtained by switching a diode ( guess 1N4007) in that “signal” path. For the complete control, I suppose you could do it with 3 relays and two diodes. Maybe there is a better way.

However, and as already pointed out, there is not enough information in that manual to do this safely. You’d have to know what you are doing. Further, I can’t imagine what circuit is interpreting these six 230 volt control signals, to give the corresponding heating profiles.

Edit

Maybe there is small heating element near the thermostat, which is fed by that control signal, probably with a series diode ?

6v6gt:
Edit

Maybe there is small heating element near the thermostat, which is fed by that control signal, probably with a series diode ?

The site listed a module that could be added for a smart phone to control the heater.
If there was a proper wiring schematic the answer would be easier to figure out

Sorry for the link, I already corrected it on the original post.

Let me just try to make some things clear from your post:

the way I interpret the signals.
no signal means local control.

No, that's not what I understand: no signal means "Confort" mode, which is simply the default, standard mode, for when you're present at the room being heated.

#4) connected to 240 = ECO, but that does not mean anything.

Eco is another mode, for saving energy. It heats at a much lower temperature, like 5º below "Confort" temperature.

if there is a device that you can buy that connects to the heater to receive WiFi commands, then that is your missing part. Get that and then sending the signals to that should be something we can help with.

I don't know if there's such a thing (well there must be...) but I'll investigate...

Thanks for your time, let's see if we can get somewhere!

Best regards, Luís

6v6gt:
Maybe there is small heating element near the thermostat, which is fed by that control signal, probably with a series diode ?

Hi.
I’m not sure I understand what you mean by this… I have not opened the heater to see where the thermostat might be. You mean that I could visually examine if there was some diode nearby?
Best regards, Luís

if your heater was properly engineered, it would require a periodic repeat of the last command or else it would time-out and shut off. Do you see any mention of such a protocol in the documentation?

Paul

luismota:
Hi.
I'm not sure I understand what you mean by this... I have not opened the heater to see where the thermostat might be. You mean that I could visually examine if there was some diode nearby?
Best regards, Luís

No. It is not necessary. This was some guess work from me. It was based on the control "signals", the timings and their effect. I tried to speculate on what circuit could use those very strange "signals" to control the heater.

In principle, if you want to control that heater using those control signals, you simply have supply those defined signals. But really, unless you can find a circuit diagram for that heater, and you understand it, you should instead use the purpose built add-on module which has been mentioned in this thread.

Paul_KD7HB:
if your heater was properly engineered, it would require a periodic repeat of the last command or else it would time-out and shut off. Do you see any mention of such a protocol in the documentation?

Paul

The way I interpret the diagram, that positive/negative signal should be permanently repeated. Maybe the drawing isn't perfect and gives the wrong impression?
Best regards, Luís

6v6gt:
In principle, if you want to control that heater using those control signals, you simply have supply those defined signals. But really, unless you can find a circuit diagram for that heater, and you understand it, you should instead use the purpose built add-on module which has been mentioned in this thread.

I tried to contact the company and ask for that add-on but I had no response. Portugal musn't be a too interesting market for them...

But if I get it right, the heater could be integrated in a "Cozytouch" system, which would not be compatible with Home Assistant nor with my other heaters... This is probably the needed accessory: https://www.thermor.fr/produits/accessoire/accessoire-connecte/interface-cozytouch (Sorry, didn't find an english version)

What I'm trying to do is to break away from proprietary systems...

Best regards, Luís Mota