#Looking for a coder/developer to help me build a custom integration for my 'smart' water heater

1 messages · Page 1 of 1 (latest)

tacit jackal
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Hello! I'm looking for someone who can help me build a custom integration for my smart water heater. I was getting help from a friend of mine, but he's currently too busy to help me out, so I'm reaching out here. I'm also open to discuss a fee if necessary. Here's the situation;

  • We live off grid. That means we collect solar power we store in LiFePo batteries. The home runs Home Assistant on an integrated Raspi4.
  • We're using a 80 liter, internet connected boiler/water heater from the brand 'Eldom'. As winter approaches, solar energy is becoming increasingly scarce, and the water boiler is our biggest power consumer. We'd like to control it through home assistant, so we can set the target temperature based on our battery status for example.
  • The water heater/boiler has it's own dedicated 'app', allowing us to control and change settings on the unit through the internet. It doesn't however have any API or other means for integration (yet) (https://apps.apple.com/sr/app/my-eldom/id1350098710%3Fl%3Dnl&ved=2ahUKEwjKls6PvIOJAxWA9LsIHSj2GgIQFnoECAsQAQ&usg=AOvVaw3oDwyY1DXmcV2ukhlsRPRh).
  • Other devs have attempted to develop an integration, but progress has seemingly halted (https://github.com/X-Terminator/home-assistant-eldom-integration).
  • My buddy already made some progress in reverse engineering the communication layers, so it seems possible to access controls from outside the official app.
  • If we are succesful I would obviously love to share the integration with other through HACS or Github.

Do you feel like this is something you'd like to develop with me? Hit me up!

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tacit jackal
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*bump

pale storm
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If you’ve managed to decipher the web calls it’s making, you can use shell and/or rest commands to basically cobble together controls for a device without writing an integration

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I did some digging and the controller is made in Bulgaria, I don’t see a lot of English chatter about it

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If you could pull in enough rest calls as switches to populate this

tacit jackal
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Thanks @pale storm for the response. You’ve managed to find something I wasn’t able to. Yes, the water heater is made in Bulgaria indeed. Sadly, I don’t know how to do any of the things you mention, as these sound like something a developer would know how to do. Sadly I don’t, hence the request for some one to help me out. Would you be able to help? Maybe have a talk some time 1v1?

pale storm
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Do you have any details about the communication that’s been deciphered so far?

tacit jackal
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The boiler/water heater is connected to the internet and comes with an app, which is basicly a web portal. By logging in with my credentials my friend has been able to extract this information;

pale storm
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Hmm yeah I think for anybody to build this integration they'd need to be able to do Wireshark packet sniffing between the mobile app and the control server

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And find out which calls they're making to operate your device

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The alternative is just install some kind of power monitoring plug and a stick on temp sensor and just treat it like a dumb device

daring panther
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Does the device support a hard wired thermostat for the temperature management? It must have something registering the temp and relaying it.

I have a boiler based heater system too, but I found some Z-Wave thermostats I could connect and control using those set points.

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I guess that wouldn’t help with the domestic hot water usage though. That’s a different set point.

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You could start with a “dumb” integration that is a reminder notification to turn down or up the set point based on weather. At least until someone figures something out.

tacit jackal
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Yeah, i've also considered using it as a dumb device, but it does have some nice features a dumb boiler wouldn't have. Having it shout down when our home battery drops below 50% though would be a nice start.

thick lily
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Hope it helps, but I am sure you already thought of that 😄

tacit jackal
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Yeah, I might actually do that. I also have the option to switch the smart plug on or off with the Victron Energy System I run, but I thinkg the Home Assistant route is the best. It's sad to see a 'Smart' appliance actually being so dumb...

digital finch
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FWIW, I built my own smart boiler controller using a digital temperature sensor (actually an ATTiny85 translating an analogue thermistor's values to 1-wire, but it would be smarter to just go directly to a 1-wire temperature sensor), and a Sonoff THR320 ESP32-controlled relay. I chose the THR320 because it is designed to have external sensors connected to it, and therefore does not "float" the ESP32's pins at mains potential, plus, the relay is rated for 20A, sufficient for my 2kW (@220V) boiler element.
The Sonoff is running ESPHome, and manages the temperature range internally, taking care never to let the relay run away and overheat the water.
Home Assistant then monitors my inverter and solar generation, and adjusts the target temperature accordingly to maximise use of the sun. i.e. if the battery is >70% SoC and charging at >2.5kW, then set the target temperature to 70C, otherwise set to 45C. This allows me to use the boiler as an energy storage "battery", presuming that the battery itself will also reach 100% under those conditions.

eager mist
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I don't have any code-help to offer, but be careful about lowering water temperature based on battery level. If it goes too low the risk of bacterial contamination vastly increases. I'm sure you know this, but just on the off chance that you hadn't thought about it.