The situation looks worrying, what is going on and is the product safe?
When heating elements reach the end of their lifetime, the heating element tube will break, causing the heating element to burn, usually resulting in a short circuit when the coil wire touches the metallic heating element tube. This, in turn, trips the fuse in the supply phase of the heating element in question.
In some situations, the heating element may begin to spark as it burns. A sudden situation may seem worrying when it appears that the heater sparks and flames may appear, but if installed correctly and taking into account that there is no flammable material in the vicinity of the heater, the safety of the product is guaranteed.
Sparks are caused by the spiral wire melting the resistance tube and the magnesium oxide. The heaters are designed and tested according to EN 60335-1 so that the sparks from the heating element do not pose a risk of fire or electric shock.
What to do in a situation like this?
The sparking usually stops spontaneously within a few seconds or until the fuse is tripped. If it lasts longer, it is advisable to manually disconnect the fuses and switch off the appliance, which will stop the sparking immediately.
Do not throw water on the heater when it sparks.
The heater should not be used until new heating elements have been replaced or the heater has been serviced. The heating elements and other spare parts used for maintenance must be original Harvia spare parts designed for the heater.
Working principle of heating element
In an electrically heated sauna heater, the heat is produced by the heating element, which consist of a stainless steel outer casing, the heating element tube. The heating element tube contains magnesium oxide as an insulating material and in the middle of the tube, inside the magnesium oxide, there is a spiral wire that carries the electric current and heats the heating element. As the heating element heats up, the spiral wire inside glows red hot, heating the surrounding magnesium oxide and the tube.
Why can a heating element burn out and how can it be avoided?
Each time the heater is used, the stainless steel heating element tube is worn out, reducing the life of the resistance. The life of the heating element is also shortened if the stones are loaded too tightly or if the wrong type of stones are used. To prolong the life of the heating element, the stones should be checked and replaced according to the manufacturer's instructions. When checking and replacing the stones, the condition of the heating elements should also be checked. The average lifetime of the heating elements varies according to the number of times they are used and the sauna conditions. A heater that has too little power for the size of the sauna will put more strain on the heater and the heating elements than a heater of the right power for the space. The average lifetime of heating elements in normal home use is about seven years. It is a good idea to proactively replace the heating elements after about six years of use or if they show obvious signs of wear.