Control your Atlantic / Thermor / Sauter heating, hot water and air-conditioning devices from Homey Pro, through your Cozytouch bridge.
Install (test channel, v1.3.5): Atlantic Cozytouch | Homey
Source & issue tracker: GitHub - NicolasYDDER/homey-cozytouch · GitHub
User guide: homey-cozytouch/USERGUIDE.md at main · NicolasYDDER/homey-cozytouch · GitHub
The app is not published to the stable App Store yet — the test channel above is how you install it today. It is not affiliated with or endorsed by Groupe Atlantic: it talks to the Cozytouch cloud through a reverse-engineered API that can change without notice.
I have been posting releases in Atlantic Cozytouch App since March, but that topic started as a general app request back in 2023. This is now the dedicated thread — please post support questions, device reports and feedback here.
What you need
- Homey Pro, firmware 5.0 or later. The app runs locally on Homey Pro only — no Homey Cloud / Bridge support.
- A Cozytouch bridge already set up, with your devices working in the official Cozytouch mobile app.
- Your Cozytouch account email and password — the same ones you use in that app.
Setup, in short:
- Install the app, then open Homey Settings → Apps → Atlantic Cozytouch.
- Enter your Cozytouch email and password, hit Save credentials, then Test connection — it lists the devices found on each protocol.
- Add devices the normal way: Devices → + → Atlantic Cozytouch → pick the device type. Credentials are reused, so you log in once, not once per device type.
How it works, and why some devices behave differently
Atlantic runs two separate clouds, and your gateway lives on one of them:
| Backend | Typically | Auth |
|---|---|---|
Cozytouch (Magellan), apis.groupe-atlantic.com |
Newer boilers, towel racks, AC, recent tanks | OAuth2 password grant |
Overkiz, ha110-1.overkiz.com |
Older water heaters, io-homecontrol, Thermor / Sauter | Atlantic token → JWT → Overkiz login |
The app logs in to both and merges the discovery, so you don’t have to know which one your bridge answers on. Each paired device remembers its protocol and commands are routed accordingly. Plenty of accounts only exist on one side — that is normal, not an error.
One global sync interval (default 60 s, range 30–300, in app settings) drives everything: each cycle asks Overkiz to refresh gateway states, then polls every paired device. Please keep it at 60–120 s — shorter risks an Overkiz QUOTA_EXCEEDED and devices dropping to unavailable.
Supported devices
Six device types: Radiator / Heating, Water Heater, Towel Rack, Heat Pump / AC, Pass Cozytouch, Shogun Zone Control.
Validated on real hardware
| Device | Type | Protocol | What works |
|---|---|---|---|
| Atlantic Kelud (500 W) | Towel rack | Cozytouch | Mode, target + measured temperature, on/off |
| Sauter Asama | Towel dryer | Overkiz | Mode, target + measured temperature, on/off |
| Atlantic Calypso (thermodynamic tank) | Water heater | Overkiz | Mode, temperature, boost, away |
| Atlantic Pass Cozytouch (ref. 602251) | Wall module | Overkiz | Heating level, on/off |
| Shogun Zone Control | Main unit + zones | Overkiz | HVAC mode, per-zone temperature + mode, on/off, heat/cool tile colours |
| Sauter / Thermor Ipala | Radiator | Overkiz | Mode, target temperature, on/off |
Mapped from user reports — should work, confirmations welcome
- Gas boilers and thermostats: Naema 2 Micro/Duo, Naia 2 Micro/Duo, Atlantic thermostats (Magellan models 56, 61, 65, 235, 418, 1444).
- Towel racks: Kelud, Kaoli, Asama (Magellan 1381, 1382, 1386, 1388, 1543, 1546, 1547, 1551, 1622, plus Overkiz
AtlanticElectricalTowelDryer_IC3). - Water heaters: Calypso including Calypso connecté 240 L (model 1658), Zeneo, Vizengo, Lineo, Égéo/MBL (Magellan 236, 389, 390, 1369–1376, 1642–1658, 1966, plus Overkiz
CETHI_V4andMBL). - Heat pumps and AC: Loria Duo R32 standard and advanced, Takao M3 series.
- The Cozytouch bridge itself (models 556, 1353) is detected but intentionally not paired as a device.
- AC controller modules (models 562–570) are detected but not mapped yet.
Mode sets differ per protocol, because the two clouds do not expose the same modes: Overkiz tanks get Off / Manual / Eco / Auto, Magellan tanks get Off / Manual / Eco / Program.
Flows
Triggers: temperature changed, heating mode changed, Pass Cozytouch mode changed, Zone Control HVAC mode changed, boost turned on/off, away mode turned on/off.
Actions: set heating mode, set HVAC mode, set Zone Control HVAC mode, set Zone Control zone mode, set Pass Cozytouch mode, turn boost on/off, turn away mode on/off.
Conditions: heating mode is…, Zone Control HVAC mode is…, zone mode is…, boost is on, away mode is on.
Plus Homey’s built-in target-temperature and on/off cards. Everything you can do from a device tile is available in a Flow.
Known limitations — please read before reporting
Changes made on a wall remote can take a while to appear. Some Overkiz devices simply do not push state to the cloud until the gateway reports in. The app runs the cloud’s own refreshStates on every sync cycle, the same family of call the official apps make when you open them, but it cannot invent an update the gateway never sent. This is a documented Overkiz platform limitation, not Homey using a different backend. Quick check: open the Cozytouch app without changing anything — if it is stale too, the cloud is behind.
A device goes unavailable. Usually the sync interval is too short and you are being rate-limited. Raise it to 120 s.
Magellan answers per product, not per model. Two tanks in the same family can implement different capability IDs, so an unsupported device can look connected but empty. The app makes that visible instead of hiding it: it dumps the capability list once per app run, falls back to the setup view when the per-device endpoint returns nothing, puts a warning on the tile when nothing maps, and reports “This control does not exist on this device model” instead of raw API JSON.
Two things are known to be missing today: away mode on Magellan tanks (it is a setup-level property whose payload isn’t mapped yet) and full mapping for the AC controller modules.
Reporting a device that doesn’t work
This is how support for new products gets added, so the detail matters. Please include:
- The commercial name and reference of the device, e.g. AQUEO ACI HYB VM 150 L 2200M.
- Which device type you tried to pair it under, and what happened: not discovered, paired but empty, or a specific control fails.
- The capability dump line from
homey app log, or a Homey diagnostic report ID. On Magellan it looks like this:
Magellan capabilities (modelId 390, productId 7, capabilities endpoint): 1 "Mode"=0, 117=52.5, …
On Overkiz, the pairing error names the device with its controllableName, e.g. Chauffe-eau (io:AtlanticDomesticHotWaterProductionMBLComponent) — that string is what the mapping is keyed on.
Bug reports with logs are just as welcome on GitHub: Issues · NicolasYDDER/homey-cozytouch · GitHub
What’s new in 1.3.x
1.3.5 — Fixes a Magellan water heater that showed no values at all (AQUEO ACI HYB VM): capability IDs now match whether the API returns them as numbers or strings, the app falls back to the setup view when the capability endpoint is empty, a tank reporting no on/off is no longer read as Off, and refused writes give a readable message. Adds a one-per-run capability dump and a tile warning when nothing maps.
1.3.4 — Calypso connecté 240 L can be added (model 1658 was missing from the water-heater family). Boost now works on Magellan tanks. The mode picker is per protocol. Pairing errors name the devices that were discovered, and the ID support is keyed on.
1.3.3 — Boost and away mode are available in Flows as triggers, actions and conditions, and the Flow triggers that were declared but never fired now actually fire.
1.3.0 — Pass Cozytouch, Shogun Zone Control and Sauter / Thermor Ipala support; one global sync interval replacing the per-device timers; log in once instead of once per device type; new Flow cards; better mobile icons.
Full changelog: homey-cozytouch/CHANGELOG.md at main · NicolasYDDER/homey-cozytouch · GitHub
Credits
Big thanks to @cedric07, who contributed the Pass Cozytouch, Shogun Zone Control and Ipala support plus the global sync work. The protocol groundwork owes a lot to the cozytouch Home Assistant integration — reverse engineering this API twice would have been painful.
And thanks to everyone in the old thread who tested builds and sent logs from hardware I don’t own. That is the only way the device list grows.
Support the app, entirely optional and bug reports help more: PayPal
I’m doing it for free on my free time. I’m expecting a bit more respectful and warm welcome.