Modern sauna heater controls make it easy to manage temperature, operating time, lighting, and ventilation while adding the convenience of smartphone access and scheduling. Options such as the HUUM UKU controller, Harvia Fenix and Xenio series, and the Saunum AirIQ control unit deliver a range of features to suit different sauna setups, from simple wall-mounted operation to advanced scheduling, remote access, and complete sauna climate management. The controller you choose plays a key role in how easily you can manage your sauna, from maintaining consistent temperatures to accessing the features that make each session more enjoyable and convenient.
HUUM UKU Wi-Fi Controller - Black
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HUUM UKU Wi-Fi Replacement Main Module
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Harvia Fenix FX45-U1-U3-XC Digital Sauna Control with Wi-Fi
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HUUM UKU Glass WiFi Controller - Black
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Harvia Xenio CX170-U1-15-XW WiFi Sauna Control - 240V(Home Use)
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Harvia Xenio CX30-U1-U3-XW Digital Sauna Control with Wi-Fi
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Harvia Xenio CX170-U3-15-XW WiFi Sauna Control - 208V(Commercial Use)
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Harvia CX30C-U1-XW
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Harvia Fenix WiFi Remote Control
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Harvia Fenix FX30C-U3-XC
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Harvia Fenix FX30C-U1-XC
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Harvia Fenix FX30-U1-U3-XC
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Saunum AirIQ Wi-Fi
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HUUM UKU Mirror WiFi Controller - White
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HUUM UKU Glass WiFi Controller - Gold
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HUUM UKU Local Controller - Black
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HUUM UKU Extension Box for Heaters 12kW and Up
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HUUM UKU Wi-Fi Controller - Wood
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HUUM UKU Local Controller - Wood
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Harvia Xenio CX30C-U3 Digital Touch Control for Virta Combi
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Sauna Heater Controls: Wi-Fi Digital Controllers from Harvia, HUUM, and Saunum
A sauna heater control is an external unit that manages temperature, operating time, lighting, and ventilation for electric sauna heaters. Modern sauna controllers feature digital touchscreen interfaces with Wi-Fi connectivity, enabling users to start, monitor, and adjust sauna settings remotely via a smartphone app.
SaunaHeaters.com carries sauna heater controls from three brands: Harvia (Fenix and Xenio controllers), HUUM (UKU Wi-Fi and UKU Local controllers), and Saunum (AirIQ Wi-Fi control unit). All controllers include safety features such as overheating protection and child locks, and are compatible with their respective brand heaters.
An external controller is required if your sauna heater does not include an integrated control panel. And if your heater already has basic controls but you want Wi-Fi access and app scheduling, a digital controller upgrade gives you exactly that.
Here is what is available, organized by brand, so that you can go straight to the section that matches your heater.
HUUM UKU Sauna Controllers
HUUM's controller lineup centers on the UKU platform, available in three configurations to match different sauna setups and heater sizes.
HUUM UKU Wi-Fi Controller
This is the flagship option. A wall-mounted control unit equipped with built-in Wi-Fi, it allows seamless operation through the HUUM mobile app on both iOS and Android devices. It controls temperature (104–230°F), operating time (3, 6, 12, or 18 hours), delayed start up to 48 hours, lighting, ventilation, and steamers.
Safety features include overheating protection, a child lock, and a door sensor. The app supports unlimited users, and the design itself has earned a Red Dot Award. It is available in Classic, Glass Black, and Main Module Only configurations. It is compatible with sauna heaters up to 9kW, but it can be expanded to support high-capacity heaters up to 18kW by using an additional HUUM extension box module.
The delayed start feature is especially useful for households with set sauna routines. You don’t have to wait for the heater to warm up once you’re home. Just set the session ahead of time so that the sauna reaches the desired temperature before you arrive. The door sensor is another thoughtful addition. It cuts power to the heater if the sauna door is left open, which protects both the heater and the room from unnecessary heat exposure.
HUUM UKU Local Controller
It offers the full functionality of the Wi-Fi edition while operating without internet or app-based control. All control happens at the wall panel. This is the right pick for saunas without reliable Wi-Fi coverage, or for buyers who simply prefer a physical panel without app dependency.
It is also a practical choice for shared or commercial sauna spaces where a fixed, straightforward interface is more appropriate than app-based access. The panel gives you everything you need to run the session, including temperature, timer, and lighting, without requiring anyone to download an app or have their phone nearby. For buyers who value simplicity and reliability over remote access, the Local Controller delivers exactly that.
HUUM UKU Extension Box
This is not a standalone controller. This point trips up a lot of buyers. If your HUUM heater is over 9kW and up to 18kW, the Extension Box is required alongside your HUUM UKU controller. It expands the controller's power handling capacity to accommodate larger heaters. It does not replace the HUUM UKU controller; it works together with it.
It functions as a connection point that links the controller to the heater and enables them to work together. The HUUM UKU controller handles the interface, app connectivity, scheduling, and safety features. The Extension Box handles the electrical load that the controller alone cannot carry.
Both pieces need to be in place for the system to run correctly on a higher-wattage heater. If you are unsure whether your heater falls above or below the 9kW threshold, check the heater's specification label or contact SaunaHeaters.com before ordering.
The most common HUUM buying mistake is skipping the Extension Box on larger heaters. If your HUUM heater exceeds 9kW, make sure you are adding both the UKU controller and the Extension Box to your order.
Harvia Sauna Controllers: Fenix and Xenio
Harvia offers two distinct controller lines: the newer Fenix and the established Xenio, along with a power extension unit for high-capacity installations. Harvia sauna heater controls are designed to provide precise temperature regulation and reliable performance across both product ranges.
Harvia Fenix
It is Harvia's newest and most advanced controller for sauna heaters. A sleek 4.3-inch glass touchscreen handles control, with Wi-Fi already built in, so everything works out of the box without needing any extra modules. It connects to the MyHarvia 2 app and includes three customizable heating presets (Mild, Cozy, Hot).
What sets the Fenix apart is its AI-based learning algorithm that studies how your specific sauna heats up and tells you when it will reach your target temperature. It controls temperature, humidity (on Combi models), lighting, and ventilation, and carries an IPX5 water resistance rating. Passcode protection and child lock come standard. It can be surface-mounted or flush-mounted, inside or outside the sauna room.
It is compatible with Harvia smart heaters: Spirit, KIP Smart, Virta Smart, Combi Smart, Club, and Cilindro. Available in multiple variants (FX30, FX45, FX30C, FX45C) depending on heater type and electrical phase. It is also fully retrofittable with existing Xenio wiring.
The retrofittable wiring compatibility is worth highlighting for anyone already running a Xenio setup. Upgrading to the Fenix does not mean rewiring the sauna from scratch. The Fenix is designed to drop into the existing wiring infrastructure, which significantly reduces installation time and cost. The IPX5 water resistance rating also means the panel can be mounted inside the sauna room itself without concern about steam or humidity affecting the electronics over time.
Harvia Xenio
Harvia Xenio is the previous-generation Harvia digital sauna controller, still widely sold and supported. Xenio sauna control is known for its simple interface and reliable temperature management. It comes in two models:
- CX110 / CX110 Wi-Fi (International): Handles power loads up to 11kW. It is sold in both a standard touch-only version and an upgraded Wi-Fi configuration (CX110XW) that natively links to the MyHarvia 2 app.
- CX170 / CX170 Wi-Fi (International): Handles higher-capacity loads up to 17kW and is similarly available with integrated Wi-Fi capabilities for legacy setups.
- CX30 / CX30 Wi-Fi (North America): Designed for North American 240V/208V systems, this model supports sauna heaters up to 11 kW (single-phase) or 10.5 kW (three-phase), making it ideal for standard residential installations.
- CX45 / CX45 Wi-Fi (North America): Built for heavier loads, this model can scale to support up to 17 kW (single-phase) or 15 kW (three-phase) configurations, though standard residential Wi-Fi retail packages are optimized for 10.8 kW loads before requiring multi-circuit expansion.
Xenio models control operating time, temperature, lighting, and fan, and can be installed inside or outside the sauna room, in a shower room, dressing room, or even a living room.
The flexible installation locations are a genuine practical advantage. Being able to mount the Xenio panel in a dressing room or hallway means household members can start the sauna and monitor the session without stepping into a hot room to adjust settings. For home saunas built into a basement or outbuilding, this kind of remote wall placement can make the whole experience noticeably more convenient.
Harvia Xenio Power Extension Unit (LTY17)
Harvia Xenio power extension units, including the LTY17 and higher-capacity LTY45/LTY45-U1-U3, extend controller capacity for large or dual-heater installations, functioning as relays with systems like the CX170, CX30, and CX45. The LTY45 specifically enables increased power handling, with capacity for up to 38kW depending on configuration, making it suitable for commercial-grade, high-load requirements.
LTY17 extends the CX170's capacity from 17kW up to 34kW. It is required for large commercial heaters or dual-heater installations. Like the HUUM Extension Box, this is not a controller — it is a power relay that works alongside the Xenio CX170.
Dual-heater setups are more common than many buyers expect, particularly in larger custom saunas or commercial wellness spaces where a single heater cannot adequately cover the room volume. If you are planning a build like that, the LTY17 is the piece that makes the Xenio CX170 viable at that scale. It is worth confirming your total heater wattage before purchasing. If you are running two heaters together, add their kW ratings to determine whether the LTY17 is needed.
One important note on compatibility: while the Fenix represents the newest smart generation, both the Fenix and Xenio can operate standard mechanical electric heaters. However, if you are looking to manage an older or legacy Harvia model, the established Xenio remains the standard choice for drop-in retrofitting.
Saunum AirIQ Sauna Controller
The Saunum AirIQ Wi-Fi control unit is the only controller featured here that goes beyond heater control and manages the overall sauna climate.
Here is what makes the AirIQ different from a standard digital sauna controller:
- Dual control: The Saunum AirIQ control unit manages both the Saunum electric heater and the Saunum Climate Equalizer, which is Saunum's proprietary integrated fan system that circulates air for more even heat distribution throughout the sauna room. This means instead of hot spots near the heater and cooler air at bench level, the entire sauna reaches a more consistent, comfortable temperature throughout the session.
- Three programmable presets: The presets let you customize temperature, time, and Climate Equalizer fan speed to match your preferred sauna style. Once saved, switching between a quick weekday session and a longer weekend ritual takes a single tap.
- Weekly session scheduling: Through the app, you can set a specific day, time, and sauna type for the entire week. This eliminates the wait entirely. The sauna is already at the desired temperature when you walk in, on whatever schedule you choose.
- Wi-Fi enabled: The Saunum AirIQ control unit works with the Saunum mobile app on iOS and Android, giving full remote control from anywhere with a phone signal. You can start a session from the office, adjust the temperature from the living room, or check the session status without leaving your seat.
- Soft-touch display panel: The panel includes overheating protection and UL listing for safety, meeting the electrical safety standards required for the North American market. The soft-touch interface keeps operation simple even for first-time users.
- Multi-language menu: From Scandinavia to North America, Saunum makes operation simple with a multilingual interface tailored for an international community of sauna users. The system can be used in English, German, Estonian, Finnish, Russian, Swedish, or Slovenian, blending Estonian craftsmanship with worldwide accessibility.
- Power capacity: The AirIQ supports heaters up to 12kW natively, and over 12kW requires a separate contactor box. If you are unsure whether your Saunum heater falls above or below that threshold, check the heater's specification label before ordering.
The AirIQ is designed specifically for Saunum heaters and is not compatible with Harvia or HUUM systems. If you use a Saunum heater and want to control the full sauna environment rather than just temperature, the AirIQ is the controller made for that purpose.
How to Choose the Right Sauna Controller
Choosing the right controller for your sauna heater comes down to three questions. Answer them in order and the decision becomes simple.
What Brand Is Your Heater?
Sauna controllers often work within their own brand ecosystem. While Harvia and Saunum systems require their matching proprietary heaters, a universal HUUM UKU controller can operate other standard heater brands. Cross-brand compatibility varies by model. If the heater brand is unknown, it should be identified first before selecting a controller.
What Is Your Heater's Kilowatt Rating?
Every controller has a native power limit. Here’s a brief overview:
- HUUM UKU handles up to 9kW natively (up to 18kW with Extension Box)
- Harvia Xenio CX110 handles up to 11kW
- Harvia Xenio CX170 handles up to 17kW (up to 34kW with LTY17 extension)
- Saunum AirIQ handles up to 12kW (over 12kW requires a contactor box)
If your heater exceeds the controller's native limit, you will need an extension unit or contactor box in addition to the controller itself.
Is Wi-Fi Required?
To operate and track your sauna remotely using a smartphone, go with a model that includes Wi-Fi connectivity. All three brands offer Wi-Fi options. If you prefer panel-only control, HUUM's UKU Local is a solid non-Wi-Fi option, and the Harvia Xenio CX110 covers that use case on the Harvia side.
One more thing worth noting: the controllers on this page are designed for traditional electric sauna heaters. Infrared saunas typically use built-in controllers specific to the infrared sauna brand. If you have an infrared sauna and need a replacement infrared sauna controller, contact SaunaHeaters.com for guidance before ordering.
Why Choose SaunaHeaters.com for Your Sauna Controller Purchase?
Purchasing a sauna controller from a sauna-focused specialist is quite different from getting one from a general electronics retailer.
SaunaHeaters.com is an authorized dealer for HUUM, Harvia, and Saunum. Every controller ships with the full manufacturer warranty. However, the bigger advantage is what happens before you buy.
Our team will verify your heater model, confirm the correct controller match, and tell you upfront if you need an extension box or contactor. This prevents the most expensive and most common mistake in the sauna heater controls category: buying the wrong unit.
If you are purchasing a new heater at the same time, the team can bundle the correct controller and any required extension units into one order — one shipment, one delivery, one support contact. And after you buy, setup guidance is available for connecting Wi-Fi controllers to the HUUM, MyHarvia, or Saunum apps, which can be tricky for first-time users.
Having HUUM, Harvia, and Saunum controllers in one place also means you can compare features, pricing, and compatibility without jumping between three different websites.
Comparison of Sauna Heater Controls by Brand and Features
| Feature | HUUM UKU Wi-Fi | HUUM UKU Local | Harvia Fenix | Harvia Xenio | Saunum AirIQ |
|---|---|---|---|---|---|
| Wi-Fi Connectivity | Yes | No | Yes | Available on Wi-Fi models | Yes |
| Mobile App Control | HUUM App | No | MyHarvia 2 App | MyHarvia App | Saunum App |
| Remote Start & Scheduling | Yes | No | Yes | Yes (Wi-Fi versions) | Yes |
| Temperature Control | Yes | Yes | Yes | Yes | Yes |
| Lighting Control | Yes | Yes | Yes | Yes | Yes |
| Ventilation/Fan Control | Yes | Yes | Yes | Yes | Yes |
| Humidity/Combi Support | Yes (with compatible systems) | Yes | Yes (Combi models) | Yes (CX30C models) | Climate Equalizer control |
| Heater Capacity | Up to 9 kW (18 kW with Extension Box) | Up to 9 kW (18 kW with Extension Box) | Depends on model (up to 17 kW+) | Depends on model (up to 34 kW with extension units) | Up to 12 kW (higher with contactor) |
| Touchscreen Display | Yes | Yes | 4.3" Glass Touchscreen | Digital Touch Panel | Soft-Touch Display |
| Best For | Modern HUUM installations with app control | Simple HUUM setups without Wi-Fi | Premium Harvia smart heaters | New or existing Harvia heaters | Saunum heaters with climate equalization |
Frequently Asked Questions
What does a sauna heater control do?
What does a sauna heater control do?
Sauna heater controls manage the core functions of an electric sauna heater: temperature, operating time, lighting, and ventilation. On Wi-Fi models, they also allow remote control and scheduling through a smartphone app.
Do I need a separate controller for my sauna heater?
Do I need a separate controller for my sauna heater?
It depends on your heater. Many electric sauna heaters are sold without a built-in sauna control panel and require an external controller for operation.
If your heater includes basic built-in controls but you want Wi-Fi sauna control access or advanced scheduling, an upgraded digital sauna controller will add those capabilities.
Can I control my sauna heater from my phone?
Can I control my sauna heater from my phone?
Yes, with a Wi-Fi controller. The HUUM UKU Wi-Fi controller works with the HUUM app. The Harvia Fenix and Xenio CX170 work with the MyHarvia 2 app. The Saunum AirIQ works with the Saunum app. All three are available on iOS and Android and allow remote start, temperature monitoring, and session scheduling, making any of them a solid choice as a sauna WiFi control solution.
Are sauna controllers interchangeable between brands?
Are sauna controllers interchangeable between brands?
It depends on the brand. While Harvia and Saunum control systems use proprietary data pathways and require their matching heaters, the HUUM UKU controller is uniquely universal. A HUUM UKU can safely operate standard electric heaters from other brands (such as Harvia) as long as the heater's kilowatt output matches the controller's capacity. Always verify your specific heater's wiring style before purchasing.
What is the difference between the Harvia Fenix and Harvia Xenio?
What is the difference between the Harvia Fenix and Harvia Xenio?
The Harvia Fenix is the newer model with a glass touchscreen, built-in sauna controller Wi-Fi, an AI learning algorithm, and compatibility with Harvia's latest smart heater lineup.
The Harvia Xenio is the previous-generation controller with a broader heater compatibility range, including older Harvia models. Both the CX110 and CX170 tiers offer optional Wi-Fi capabilities via their respective “XW” or Wi-Fi configurations; the choice between them is based purely on your heater's kilowatt capacity rather than wireless access.
If you have an older Harvia heater, the Xenio is likely the right fit. If you have a newer Harvia smart heater, the Fenix gives you more features and smarter performance.
What is the HUUM UKU Extension Box for?
What is the HUUM UKU Extension Box for?
The HUUM UKU Extension Box extends the UKU controller's power handling capacity from 9kW up to 18kW. It is required for HUUM heaters over 9kW. It is not a replacement for the UKU controller. It works alongside it. If you have a larger HUUM heater and order only the UKU controller, the system will not function correctly.
Do infrared saunas use the same controllers?
Do infrared saunas use the same controllers?
Infrared saunas use built-in controllers specific to their brand and heating system. The heater controls on this page are designed for traditional electric sauna heaters only. If you need an infrared sauna controller, contact SaunaHeaters.com directly for guidance on your specific unit.
Which sauna controller has the best app?
Which sauna controller has the best app?
All three brands offer capable apps. The HUUM app supports unlimited users and is well-regarded for ease of use. For Harvia setups, the MyHarvia for Xenio app runs older digital models, while the next-generation MyHarvia 2 app operates the Fenix, incorporating predictive temperature alerts from the system's AI learning curves. The Saunum app handles both heater and Climate Equalizer controls in one place, which is unique among digital sauna controllers. The best choice depends on your heater brand. The apps are not interchangeable.
