There is no need to do any special maintenance of sauna stove from Ukko Saunas , besides wiping its surfaces. Use only soft cloth and mild detergent to wash the stove. Do not use hard brush or steel wool. This can scratch the stove finish and cause rusting.
If having problems with the stove always consult with certified electrician in your area. It is highly dangerous to do your own electrical repairs unless you really know what you are doing.
From time to time as a normal wear and tear process your heater would require element replacements. It is advisable to ask your heater supplier if they carry elements in stock.
Otherwise it might become an expensive exercise and you might as well consider changing the supplier. Never use sauna stove without rocks as it can cause elements burning.
A wood-burning heater, on the other hand, requires a bit more maintenance. The ashes must be removed on a regular basis and the exhaust pipe must be kept clean of obstructions.
Be careful of creosote build-up in the exhaust pipe. It can be a dangerous fire hazard, so regular inspection is a must to ensure the safety of your sauna.