Using your new sauna for the first time

The short answer

• Read the heater and control manuals first. They are the instructions that apply to your equipment, and they override any general guide, including this one.
• Wash and load the stones correctly before the first heat: loosely, with the elements covered and nothing wedged against them.
• Expect a smell on the first heats. Run them with nobody inside and the room well ventilated until the smell clears.
• Give the heater about an hour to bring the room and stones up to temperature.
• Start gently: a moderate temperature, a short session and small ladles of clean water.
• Switch off and dry the room afterwards, and check the heater has actually stopped heating.

Before the first heat

A few checks make the first heat uneventful:

• Find the manuals for the heater, the control and, if you have one, the steam or combi equipment. Note the heater model from its model plate; you’ll need it for stones and any service call.
• Check the stones are loaded, and loaded correctly (see below). A heater must never be run without its stones.
• Clear the heater. Nothing on it, against it or hanging over it: no towels, packaging, buckets or offcuts from the build.
• Open the vents as the ventilation design intends. Fresh air in and stale air out is part of how the room was designed to heat, and the first heats need it to clear the smell. The supply and exhaust stay open while the heater runs; only a closable drying vent, if fitted, is kept closed while heating and bathing (Harvia).
• Look around the room before switching on. Harvia’s control manuals ask users to check the room and the area around the heater before every start, and before any timed or remote start.

Washing and loading the stones

If the stones aren’t in the heater yet, they need to go in before anything else. The short version, from Harvia’s instructions:

1. Heater off and cool. Wear gloves.
2. Rinse the dust off the stones. Dust left on them burns off as a smell and stains the floor and timber.
3. Sort them by size and start with the largest at the bottom.
4. Place them one at a time. Never wedge stones between or against the elements; stones should support each other and keep the elements upright.
5. Keep a denser outer layer where the manual shows one and a loose middle, so air can rise through the heater.
6. Cover the elements fully, without building a high pile on top.

Use only the stone type, shape and size the heater’s manual specifies. Our sauna stones guide explains each step and why it matters.

The first heats: what to expect

Harvia’s guidance

Harvia’s manuals are consistent on this across its heater range. The first time the heater is switched on, the heater and the stones give off a smell. The room must be well ventilated until it clears. Harvia’s Spirit manual says to allow for the smell “the first few times”, not just once.

The smell comes from manufacturing residues on new elements and from dust on the stones burning off. It is expected and it fades.

How other makers put it

Other manufacturers give more specific routines for their own heaters. They show what good practice looks like, but follow the manual for your heater:

• One Finnish maker says to set the maximum temperature and run the heater for about 30 minutes with nobody inside, then ventilate, and repeat if needed. It says to do the same after an element is replaced.
• A Swedish maker asks for the first heat to run at about 90 °C for about an hour.
• A German maker describes a slight smell on first heating as normal and asks for the room to be aired before use.

The common ground: heat the empty room, ventilate it, and repeat if the smell is still noticeable.

Different heater types

Smells that aren’t the heater

Harvia’s troubleshooting notes that a hot heater makes smells already in the air more noticeable: paint, glue, heating oil or cooking spices, for example. The heater isn’t producing them. In a new home or a fresh renovation, finishes in the surrounding rooms are a common source. Ventilate, and the smell should fade as the building finishes cure.

Getting to know the controls

How you start and stop the heater depends on the control. Broadly:

• Controls on the heater itself. Some heaters have switches and a timer on the heater body. Harvia’s built-in timer models have an “on” range plus a pre-set range that starts the heater later. Harvia’s tip for these thermostats: start at maximum and turn down, because small changes near the top of the dial make a big difference.
• A separate control panel outside or inside the room, with a temperature sensor mounted high on the wall or ceiling near the heater. You set the temperature and the session time on the panel.
• App or remote start. Harvia’s controls only allow remote or timed starts when a safety device is fitted, such as a door switch or a heater cover sensor above the heater that detects anything covering it (or the heater is certified to the covering test the control’s manual names), and some controls block a remote restart for a set rest period after the heater last switched off. Remote starting is convenient, but it doesn’t remove the need to check the room first.

Harvia’s controls have a built-in limit on how long the heater can run, with longer limits allowed only for commercial use. Don’t treat the timer as your off switch; switch off when you finish. And don’t touch, move or cover the temperature sensor. It controls the heater and protects against overheating, so it has to stay where it was installed.

Our controls guide explains sensors, timers and remote-start safety in more detail.

Heat-up and temperature

Harvia says a correctly sized heater in a properly insulated room takes about an hour to bring the room to bathing temperature, and the stones reach temperature at about the same time. Starting a session early, before the stones are fully hot, is the most common reason the first ladle of water disappoints.

Harvia’s Cilindro manual suggests about 65–75 °C as a suitable room temperature. Other heater makers suggest ranges up to about 80 °C. Two things to keep in mind:

• The setting is not what you feel on the bench. The control’s sensor sits high up near the heater, where the air is hottest. The upper bench is cooler than the setting, and the lower bench cooler still.
• Start gently. A moderate setting for the first few sessions lets you find what suits you and how your room behaves.

Our guide to how a sauna heats explains why temperatures differ through the room.

Your first session

• Read the safety warnings in your heater’s manual. They cover supervision of children, health conditions and other cautions, and they apply to every session, not just the first.
• Sit on a towel. Bench towels keep perspiration off the timber, which is why heater manuals ask for them.
• Start on the lower bench and move up if you want more heat.
• Keep the first session short, and leave the room whenever you feel uncomfortable.
• Keep the heater clear. Never drape a towel or clothing over the heater or the guard, even briefly.

Water on the stones

Throwing water on the stones is what makes a sauna a sauna: the water flashes into steam, the humidity rises and the löyly rolls down over the benches.

• Small ladles. Harvia’s manuals set a maximum ladle volume of 0.2 litres. Too much at once doesn’t all evaporate, and water can splash boiling off the stones.
• Onto the stones only, never at the heater casing, the guard or the walls, and never when someone is near the heater.
• One ladle, then wait. Let the steam settle and the stones recover before the next. One German maker suggests about 100 ml per cubic metre of room per throw, then about 10 minutes for the stones to reheat; a Swedish maker suggests one or two ladles at a time. Watch how your stones respond.
• Clean household water only. Harvia publishes limits for minerals in sauna water and prohibits chlorinated water and seawater. Never use pool or spa water. If you are on tank or bore water, check it against the limits in your heater’s manual.
• Scents as directed. Use only fragrances made for sauna water, diluted as their maker directs. Neat essences, alcohol and herbs on the stones can catch fire.

If water runs through the stones instead of flashing off, the stones aren’t hot enough yet. Give the heater more time. If it keeps happening once the room is fully hot, that’s worth reporting (see below).

After the session: switch off and dry

Drying the room after every session is the habit that does most to keep a sauna’s timber in good condition.

1. Switch the heater off, unless you are deliberately running a short drying heat. Harvia notes that leaving the heater on briefly after bathing can help dry the timber; its care instructions suggest about 10 minutes with the vent open and the door ajar. Another maker suggests 30 minutes. Follow your heater’s instructions.
2. Check that the heater has actually stopped heating when you switch it off or the timer ends. Harvia asks users to check this every time.
3. Some controls dry the room automatically. Harvia’s Xenio control, for example, can hold the room at about 40 °C for 45 minutes after switch-off, with the fan running if one is connected. If your control has a drying cycle, let it finish.
4. Take everything out: towels, clothing and the bucket. Leave no standing water.
5. Wipe the benches and leave the vents and door as your manual describes so the room can dry.
6. Combi heaters: once the heater has cooled, drain the water reservoir. Harvia says to do this after every use, so impurities don’t concentrate.

Our care guide sets out the full routine, from cleaning to yearly stone care.

What’s normal and what to report

Don’t reset an overheat protector yourself. On many Harvia heaters the reset button is inside the heater’s connection box, and Harvia says only a person authorised to carry out electrical installations may reset it, after the cause has been found. Crumbled or compacted stones, a heater left on unused for a long time, a displaced or faulty sensor, or a knock to the heater are among the causes Harvia lists.

For any of the items in the right-hand column, stop using the room and get help. Our service page explains how a service request works, or contact us with the heater make and model and what you are seeing.