Finnleo CB17-1 Contactor Box (1-phase, Laava & Magma)

Finnleo CB17-1 Contactor Box (1-Phase) — Laava & Magma Sauna Heaters

What the CB17-1 Contactor Box Does

The Finnleo CB17-1 Contactor Box is the dedicated single-phase power relay engineered for Finnleo's Pro Series sauna heaters — Laava and Magma. Because these commercial-duty heaters draw significantly higher current than residential models, the low-voltage signal from a SaunaLogic2 control (SL2 or SL2-C) cannot switch the heater's line-voltage circuit directly. The CB17-1 solves this by housing the heavy-duty electrical contactors that receive the low-voltage command from the control and switch full line power to the heater's elements safely and reliably. Mounted outside the sauna enclosure in a dry, accessible electrical space, it is rated for a minimum ambient temperature of 90°C, keeping the switching hardware protected from heat while positioned close enough to the heater circuit for a clean, code-compliant installation.

Heater and Electrical System Compatibility

The CB17-1 is required specifically for single-phase electrical service on Finnleo's Pro Series lineup — the Laava heater (available in 240V or 208V) and the Magma heater in its single-phase 208V/480V configurations. Unlike the residential Designer SL2 and Himalaya heaters, which pair with the CB16 series, Laava and Magma's higher kW output (Magma spans 21.0, 24.0, and 28.8 kW models across a 720–2,000 cubic foot room range) demands the CB17's heavier-duty contactor rating. On dual-heater configurations — common in larger commercial saunas using two Magma floor heaters — two CB17-1 boxes may be required to serve each heater independently. Three-phase Laava and Magma installations instead require the CB17-3, and certain 208V three-phase Magma setups additionally require a CB18-3 in tandem. Because contactor sizing is tied directly to heater kW, voltage, and phase, always confirm your exact heater model and electrical service before ordering — pairing the wrong contactor box can prevent proper operation or fail electrical inspection.

Construction & Installation

The CB17-1 is built as a rugged, self-contained electrical enclosure housing UL/NRTL-listed contactors rated for continuous commercial sauna duty. It connects on one side to the low-voltage control wiring coming from the SaunaLogic2 control head, and on the other to the incoming line-voltage feed and the outgoing circuit to the heater elements. Like all Finnleo contactor boxes, it must be installed by a qualified electrician outside the sauna room, in accordance with local electrical code and the clearance/temperature requirements specified in the heater's installation manual. Its enclosure is designed for wall or panel mounting near the heater's electrical disconnect, keeping wiring runs short and serviceable.

Why the CB17-1 Matters

Without the correct contactor box, a SaunaLogic2 control cannot safely operate a Pro Series heater — the control's low-voltage touchscreen and app electronics are simply not built to switch line-voltage loads at commercial kW levels. The CB17-1 is the component that makes the entire SaunaLogic2 experience — touchscreen operation, Wi-Fi app control, scheduling, and voice assistant integration — actually function on Laava and Magma installations. It's a small, unglamorous box, but it's the electrical backbone that lets a large commercial or high-demand sauna respond instantly and safely to every command sent from the control head or the app.

Why Choose Finnleo

Finnleo, built by Sauna360 in Cokato, Minnesota, is one of the most trusted names in authentic Finnish sauna, and every component in its SaunaLogic2 ecosystem — from the touchscreen control down to the contactor box — is engineered, tested, and listed to work together as a matched system. As an authorized Finnleo dealer, we offer full factory warranty coverage, expert help matching your CB17-1 to the correct heater and electrical service, and support before and after your purchase. Not sure whether your Laava or Magma installation needs one CB17-1 or two, or whether your service is single- or three-phase? Send us your heater model and electrical specs and a sauna specialist will confirm the exact pairing before you order.