Where sauna gauges are mounted and why

The spot you pick changes the number. Makers know this. Some give distances, and the sections below say which part each one applies to, so you don't mix up a wall gauge with a control sensor.

A wall thermometer

One maker of a 4-inch round wall thermometer says installation location will greatly impact results.¹

• Away from the heater and door. At least three feet (about 0.9 m) away when possible.¹
• Down from the ceiling. Roughly one foot (about 30 cm).¹

That's one maker's accessory page. Your own gauge's manual takes priority.

A heater-control sensor

This isn't a wall gauge you read. It feeds the heater's control. Its distances are tighter, and they show how makers think about placement. The figures below are one maker's rules for its own system.

• From corners and openings. At least 20 in / 50 cm away from the corners of the sauna room and from air openings such as the door, window and ventilation.²
• From the ceiling, on a wall. Not more than 6 in / 15 cm.²
• From the heater. Not directly above it, but 20 in / 50 cm from its outer edge.²
• If the wall can't take it. When the sensor can't go on the wall at those distances because of room size or construction, it must be placed on the ceiling.²
• The control panel. That maker says it should be installed outside the steam room, and that only its glass and wooden case control panels can be installed inside the sauna room.²

Wiring a heater control is licensed electrical work. It isn't a DIY job. Follow the heater and control manuals for your model.

Why the distances look like this

• Height. Benches near the ceiling run hotter than low ones.³
• Doors and vents. The air openings are named in the maker's rule, which is why it keeps its sensor 20 in / 50 cm from them.²
• Right over the heater. That maker says the sensor shouldn't sit directly above it.²

Hygrometers and combined gauges

Maker pages for combined gauges tend to give sizes rather than positions. They're built to fix to the wall.

• One lists its installation location as the wall, and says it helps you monitor the temperature and humidity of the sauna room.⁴
• Another is 220 mm tall and 205 mm wide, with a 40 mm recess, and goes in with 5 stainless steel screws.⁵

Recessed gauges mean cutting into wall paneling. Check the recess depth against your wall first.

Before you drill

• Find the maker's installation sheet for your exact gauge.
• Measure from the heater, the door and the ceiling.
• Keep any fixings clear of the minimum clearances in the heater manual. A wood-fired stove has its own clearance and flue rules, so follow its manual and your local building and fire rules. Such a stove also carries a carbon monoxide risk: an unvented room is never safe for one.
• Note the spot you pick, so later checks use the same one.