[App][Pro] Danfoss Ally

If you’re like me and using Danfoss Ally products for managing the temperature in your home, you probably missed decent options to integrate these products in your automation flows. As far as I know the only option was to have them run via the Tuya app.

This app does what the Danfoss Ally app can do. It requires setting up a developer account at Danfoss (explained below) and uses their API to read and control the devices.

A big thanks goes to the developer(s) that made the HomeAssistant app. They did al the heavy lifting. All I did was instruct my AI Agent (Claude) to port the code. Honestly, I did some testing of course but that’s about it. You can buy MTrab a coffee via this link: https://www.buymeacoffee.com/mtrab.

Supported devices

I’m limited to the devices below, these are all I have. I’m willing to help out to get more device types connected but since I don’t own them that might be a little bit harder to accomplish. Just so you know.

  • Danfoss Icon2 Main Controller (no capabilities)

  • Danfoss Icon2 Room Thermostat with IR floor sensor

  • Danfoss Icon2 Room Thermostat

  • Danfoss Icon2 Room Sensor

  • Danfoss Ally Radiator Thermostat

  • Danfoss Ally Room Sensor

  • Danfoss Ally Gateway (no capabilities)

  • Danfoss Ally Zigbee module

Flow charts

All default thermostat and sensor flow charts are available to use. Read and react on temperature or humidity changes and set temperatures in your rooms.

Installation

After installing the app you must register and create an application at https://developer.danfoss.com. It’s as easy as signing up and creating the app via your user menu. Choose a name and make sure to select Danfoss API on the right side. After saving click on your app name where you’ll find the app id and secret codes.

Make sure both your Danfoss Ally app and the developer account use the same emailaddress!

In your Homey visit the apps page, open Danfoss Ally and add both codes to their respective fields in the settings. As soon as you’ve done that, you can add the devices, add them to the correct rooms and start automate the temperature settings or use temperature/humidity values in other flows.

I’ve created a little video how-to on what steps to take:

Roadmap

Right now there are no plans for new features, but feel free to request things you’re missing.

Changelog

  • 06/01/2026: First public release

Homey Appstore

Source code

I’ve open-source the source code of this app. It can be found in the Github repository below. Feel free to contribute.

In the Ally mobile app; if you put both the temperature sensor and the thermostat in the same “room” the thermostate will start using the temperature measured from the temperature sensor instead of the built in. In this way the measurement will be more accurate and not affected by say cutains.

Will this still work after including the devices in Homey?
Are the devices fetched/included through the Ally main controller?

I’d honestly don’t know for sure, but as far as I could tell technically nothing changes to the working of the sensors.

The app reads al devices via the Ally Cloud API and only supports reading the values (temperature and humidity) and setting the temperature. So any readings happen exclusively via the cloud. This means it would be super weird if you got other readings in Homey compared to your app, because they both use the same source.

Reading through cloud should not affect the connection between the thermostat and the temperature sensor, good.

Nice app! I have missed it.

I’m going to try to get most available devices supported anytime soon (taking example of the Danfoss app by Athom: Danfoss | Homey ). Hopefully the API returns some type-specific data that can be used to filter down to the exact device - for example: my room thermostat in the living room turns up as the same device as the radiator thermostat. Functionality-wise they’re the same but would be nice to get the exact types visible.

I’ve request help from Athom to get the images and icons used in the official app.

2 Likes

This sounds promising especially when the sensor function works. However I’m not able to add the app. It requires some sort of syntax. Only Homey will not do. The submit button doesn’t respond. What am I doing wrong?

Can you provide any error messages or screenshots? I’m not sure what the syntax requirement is you’re talking about. With a bit more context I might be able to help.

Thanks!

It concerns this screen.

Not really sure what I need to fill out for app name.

Ah, right, the app at Danfoss. I thought it was about the Homey app.

I named mine danfoss-homey-non-prod, I don’t think it really matters. Right now it should be “prod”, but there is nothing that limits the use. Neither did it error because I used -non-prod instead of (NON-PROD). So.. just name it whatever makes it easy for you to know what you use it for, “Homey” should do the trick.

Leave callback and description blank and after saving you should be able to see/copy the app id and app secret codes that you need to enter in the Homey app settings.

I quickly created a how-to video for you:

Awesome! Thanks for your help.

I had to add the Ally API on the right side as well. Didn’t see that. Now it works!

Yeah, I’ve added it to the first post and it’s in the video too! Thanks for noticing.

I will try tomorrow if the room sensor function works as master for the thermostat.

I guess with this I won’t be needing the Danfoss Gateway anymore because Homey replaces it?

I doubt that - the gateway is what connects your devices to the internet and what responds to API requests we send to it. At best I’d say you remove all settings from the Ally app (I think that’s mostly schedules) and have Homey control that.

I still have to figure out some things, for instance there is a setting in the Alley app to enable Open Window Detection. That’s not available in this app (yet).

Removing the gateway could work, but only when you connect your devices via Zigbee to Homey directly. This app does not work if you do so, this one relies completely on the “iot setup”: Thermostat → Ally gateway → router → Danfoss web API.

Right. I now have my devices connected through Smartlife and the Tuya app. So added the gateway in Smartlife with thermostats and sensors and then to Homey through Tuya app.

If I understand this right I should now use the Danfoss ally ios app for this and then add the devices to Homey with your app?

Obviously after removing them from Smartlife first.

Yes! And I think I must add a little disclaimer to the instructions: the Danfoss developer app should be registered using the same e-mailaddres as used for the Danfoss Ally app. As I can’t see how else it should now what devices to fetch from the API.

A new test version is on it’s way - I’ve tried to separate a few device types based off their capabilities and/or name in the Ally API. It looks like I can get the devices below, but since I don’t own all of them I can’t say for sure.

  • Danfoss Icon2 Main Controller
  • Danfoss Icon2 Room Thermostat with IR floor sensor
  • Danfoss Icon2 Room Thermostat
  • Danfoss Icon2 Room Sensor
  • Danfoss Ally Radiator Thermostat
  • Danfoss Ally Room Sensor
  • Danfoss Ally Gateway
  • Danfoss Ally Zigbee module

New test version available:

I’ve added the Danfoss Ally zigbee gateway to see if it works and it does. Device is added to Homey but not quite sure what it does since there are no controls and also not sure what’s meant by ‘boiler relay’ ?

Other than that app works like a charm. Thanks

The Gateway should be able to decide on an “is heating” boolean - but I haven’t tested that yet. I could discover the device type so I added it to support the full range of devices. I’ll look into that later.

The app is approved and live for all users: