Benches and walls
Wipe with a damp cloth and dry the wood. Do not soak it and do not use solvent cleaners.
The heater
Let it cool completely, then vacuum dust from the guard. Never touch the elements with a wet cloth.
Stones and steam
If your model uses stones, rinse them occasionally and replace cracked ones. Only use stones rated for the heater.
Long absences
Switch off at the breaker, dry the cabin and leave the door open for a day.