Sauna Heater with Wifi Control

What WiFi Control Actually Does

The pitch is obvious: pre-heat your sauna from the car so it's ready when you walk in. That's the main use case, and it's genuinely useful — a sauna that takes about an hour to warm up (Harvia's figure for a correctly sized heater in a properly insulated room) becomes a zero-wait experience.

But the feature set goes deeper than remote start:

• Scheduling. Set recurring sessions — "warm up every Tuesday and Thursday at 6pm" — and the heater handles it without you touching anything.
• Temperature adjustment mid-session. Change the target temperature from your phone without getting up from the bench.
• Status monitoring. See if the sauna is currently on, what the interior temp is, and how much time is left — useful when you've got multiple family members using it.
• Usage tracking. Most apps log session history — how long, what temperature, how often. Not life-changing, but some owners find it useful.
• Firmware updates. Controllers receive over-the-air updates with new features and bug fixes.

If you're just going to walk out to a wall panel and set the temperature, you don't need WiFi — the local version of each controller costs less.

The Three WiFi Controller Systems

HUUM UKU (All HUUM Heaters)

HUUM's UKU system runs every HUUM heater — DROP, CLIFF, CLIFF Mini, STEEL, STEEL Mini, HIVE Mini, HIVE. Controllers are sold separately from heaters so you can match aesthetic to your space:

• UKU Local: Wired, no WiFi. Black, white, or wood-finish panel.
• UKU WiFi: Same physical panel, WiFi module inside. Black, white, or wood.
• UKU WiFi Glass: Minimalist glass-front panel. The design-forward option.
• UKU WiFi Mirror: Mirrored front — the controller disappears into the wall when off.

All WiFi versions connect to the HUUM app (iOS and Android). The full HUUM collection shows every heater/controller combination.

Harvia Xenio (Virta, Cilindro, Club, Spirit, Virta Combi)

Harvia's Xenio is a modular system: base controller + optional WiFi module. You can buy the Xenio CX170 controller as a stand-alone local unit and add the Xenio WiFi module later, or get both together in a bundled Harvia heater package.

Xenio controllers come in several models to match heater size: CX170 (in 240V single-phase and 208V three-phase versions), CX30 and CX45 for the Club, Spirit, Cilindro and Virta lines, and CX30C for the Virta Combi (handles the steamer separately). The MyHarvia app covers all of them.

Saunum AirIQ-WIFI (Air & Air L Series)

Saunum's AirIQ is purpose-built for their Air heater line with the climate equalizer fan. In addition to standard WiFi features, AirIQ controls the fan speed — so you can adjust how aggressively the heater circulates air to equalize upper-bench and lower-bench temperatures. AirIQ is also the only control Saunum approves for its heaters — Saunum's manual says any other control voids the warranty and the UL listing.

Remote Start: What the Manuals Require

Remote starting depends on the control's own safety devices, as set out in each manual: HUUM's UKU kit includes a door sensor, and its manual says to remove any items from the heater and close the door before starting it remotely; Saunum's AirIQ can be run remotely only once the heater or sauna door has a door sensor; and Harvia's Xenio supports a safety switch, such as the Harvia SFE, that stops the heater if something falls onto it. Your electrician confirms any additional local requirement.

1. Scheduled starts count as remote operation too: Harvia's Xenio manual says its pause-time setting must be enabled when the heater is started by an automated schedule, such as a weekly timer.
2. Before any remote start, check that nothing has been left on or near the heater and that the sauna door is closed, as HUUM's manual instructs.

Your installing electrician should confirm whether your jurisdiction adds any requirement of its own.

Choosing the Right WiFi Heater

The WiFi controller doesn't change the fundamentals of heater selection. You still pick based on room size, power requirements, and stone capacity. Quick decision tree:

• You want the cleanest app experience and premium design: HUUM with a UKU WiFi Glass or Mirror controller.
• You want the widest choice of outputs or a three-phase option: Harvia Virta, Cilindro or Club with the Xenio WiFi module. Harvia's warranty is 2 years in family use, plus 1 more year for electric heaters registered within 30 days of purchase.
• Your sauna has uneven heat and your feet are always cold: Saunum Air with AirIQ-WIFI — the climate equalizer is the differentiator, not the app.
• You want the combi (dry + steam) feature: Harvia Virta Combi with the CX30C Xenio WiFi package — the only heater-and-steamer combination in this collection.

Power selection follows each heater's manufacturer-rated room range, after you add the allowance for glass (Topture's heater size calculator does the arithmetic). See the 9kW comparison page if your room is in that range, or 10.5kW options for larger rooms.

Does WiFi Actually Work in a Detached Outdoor Sauna?

This is the question nobody asks until after they've installed a heater and realized their backyard WiFi signal dies 50 feet from the house. Three options:

1. WiFi extender. A mesh node or extender in the garage or a window facing the sauna.
2. Outdoor WiFi access point. A weatherproof AP mounted on the exterior of the house. Strongest signal but requires ethernet run from the main router.
3. Check the band. HUUM's UKU WiFi and Saunum's AirIQ connect to 2.4 GHz networks, not 5 GHz, so make sure your extender or access point offers 2.4 GHz.

Before assuming your WiFi reaches the sauna, test the signal at the exact install location with a phone. If you're under 3 bars, plan on an extender.