These release notes summarize the customer-facing improvements introduced since Control Panel and Power Unit version 1.2.0 and AutoLeil version 1.8.0. This Stability Update focuses on system reliability, firmware updates, expanded Modbus functionality, AutoLeil improvements, and overall usability.
New AirIQ manual
New Modbus spec
Updated AutoLeil manual (GLOBAL)
Updated AutoLeil manual (US)
Connectivity and automatic recovery
- Improved system communication and recovery following temporary Saunum server connection interruptions.
- Improved Wi-Fi connection handling and recovery after certain rare network disruptions.
- Updated the Wi-Fi status indicator to better distinguish between Wi-Fi, Internet, and Saunum server connection problems.
- Improved reconnection to previously saved Wi-Fi networks without immediately requesting the password again.
- Improved communication recovery between the Control Panel and connected system components.
Firmware updates and recovery
- Improved firmware update reliability for the Control Panel, Power Unit, and AutoLeil.
- Improved the firmware Updates screen by displaying already-installed versions in grey, making them easier to distinguish from available updates while retaining the option to reinstall firmware when needed for recovery.
- Added additional recovery mechanisms for Power Units left in bootloader mode following interrupted firmware updates, reducing the need for manual recovery in supported situations.
- Improved firmware validation, error handling, and recovery during unsuccessful or interrupted updates.
- Improved software version detection and reporting for connected components.
- Reduced repeated notifications for the same available firmware update.
- Firmware update notifications are now postponed during active sauna sessions and Cooling to avoid unnecessary interruptions.
Sauna sessions and scheduling
- Improved scheduled-session timing and handling of time regions and daylight saving time.
- Improved active-session recovery following unexpected Control Panel restarts or temporary communication interruptions.
- Improved synchronization of session settings, remaining time, and operating states between the Control Panel and Power Unit.
- Improved transitions between Heating, Ready, Cooling, and Standby.
- Refined Power Unit heating regulation by reducing the preheating cutoff to 5°C below target and the coasting timeout from 180 to 120 seconds. During the final 2°C approach, heating now increases from 1 to 3 coils if the target is not reached within 120 seconds of 1 coil being active (previously no timeout). After reaching target, single-coil heating stops at 2°C above the target, restarts at 1°C below, and increases to 3 coils at 5°C below.
Cooling and fan control
- Extended the minimum Cooling period to 60 minutes. Cooling automatically ends after this period once the sauna temperature falls below 50°C.
- Added more flexible fan-duration and fan-speed controls directly from the Cooling screen.
- Improved physical fan-button responsiveness and synchronization with touchscreen controls.
- Improved ventilation countdowns and fan-timer display behavior.
- Improved synchronization between Cooling and the Power Unit’s fan-only operation.
Modbus TCP functionality
- Significantly expanded Modbus TCP functionality for smart home and building automation integrations.
- Expanded remote control of sauna session settings, target temperature, session duration, fans, and lighting.
- Added additional AutoLeil configuration and control through Modbus.
- Expanded monitoring of operating states, temperatures, heating elements, session timers, alarms, and diagnostics.
- Added additional remote functions, including software reboot and Cooling dismissal.
- Improved remote command handling, settings synchronization, and Modbus communication stability.
- Preserved compatibility with existing Modbus register addresses while introducing additional functionality.
AutoLeil functionality improvements
- Improved automatic and manual water dispensing behavior throughout sauna sessions.
- Improved AutoLeil operation and synchronization during Heating, Ready, Cooling, and Standby.
- Refined humidity-based and interval-based automatic dispensing.
- Improved physical-button operation, timeout handling, and synchronization with the Control Panel.
- Improved application of AutoLeil settings without unnecessarily interrupting active operation.
- Improved temperature-dependent activation and automatic deactivation.
- Added support for manual water dispensing during Cooling when permitted by temperature and safety conditions.
- Improved automatic ventilation behavior following water dispensing.
- Improved synchronization of operating modes, duration, water quantity, Ready mode, and other settings.
- Added AutoLeil heating assistance, allowing up to 3 heating coils to operate near the target temperature during initial heat-up when the AutoLeil button is pressed before the sauna reaches Ready, helping prevent heating stalls.
User interface and settings
- Improved touchscreen responsiveness and visual feedback.
- Corrected keyboard input behavior and additional missing symbols and translations.
- Updated region naming and related settings to use Global instead of EU where applicable.
- Updated the heater list in the settings to reflect the rebranded Saunum product names.
- Updated minimum sauna session and AutoLeil automatic-operation durations to 60 minutes.
- Improved the consistency of session, fan, and operating-state information displayed on the Control Panel.
System stability and diagnostics
- Optimized internal memory management to improve stability during regular use, networking, firmware updates, and Modbus operation.
- Improved handling of temporary low-memory conditions and communication failures.
- Improved background-task handling to reduce unnecessary system interruptions and watchdog resets.
- Expanded diagnostic reporting for system communication, firmware updates, heating elements, and connected components.
- Improved logging of session activity, operating states, alarms, and AutoLeil water-dispensing events.
- Reduced unnecessary repetitive diagnostic messages during normal operation.
Important notes
- Available functions may depend on device configuration, connected hardware, and regional restrictions.
- The expanded Modbus functionality is documented in the updated Modbus TCP specification.
- Existing safety protections and operating limits remain in effect.
- For full compatibility, both the Control Panel and Power Unit must be updated. If AutoLeil is installed, it must also be updated.
- We recommend reviewing the latest Control Panel and AutoLeil manuals, as several aspects of everyday operation have changed, particularly AutoLeil functionality and controls.
