Thread, flange, smooth or sleeve
The mounting type can be seen directly on the old igniter. An igniter with thread is screwed into a threaded hole in the stove, and the vast majority have 3/8" thread, while some models have 1/2" or 1/4". In some stoves, the igniter is fitted in an igniter adapter with 3/8" thread.
An igniter with a flange has a flat collar on the tube that rests against the stove and determines how far the igniter protrudes. Smooth igniters without thread have neither thread nor collar and are instead held in place by an igniter holder or by two crescent-shaped clamps, depending on the stove.
The sleeve models are the most powerful, with an outer diameter of 20 to 25 mm, because the heating coil is enclosed in an additional metal sleeve. The other steel igniters are typically between 9.5 and 12.5 mm.
How to determine the thread size
The thread size is measured with calipers across the thread crests. Igniters typically use gas threads, where 1/4" measures approx. 13.2 mm, 3/8" approx. 16.7 mm and 1/2" approx. 21 mm in outer diameter. The inch designation is a standard designation that does not correspond to a measurement of the thread itself, so a 3/8" thread therefore does not measure 9.5 mm. The difference between the three sizes is so great that a single measurement provides a reliable answer.
When it looks like the old one without fitting
Many steel igniters look alike, and small differences determine whether they work in the stove. The range includes Ø12.5 x 150 mm with both 250 and 350 watt, Ø9.9 x 130 mm with 270 and 300 watt and Ø9.9 x 140 mm with 300 and 350 watt. The power must therefore match the old igniter, as must the diameter, length and mounting type. An igniter with lower power heats up more slowly, and the stove may reach an ignition alarm before the pellets have ignited.
The length determines how far the tip reaches into the burn pot, so even a few millimetres can mean that the heat does not reach the pellets. The universal models are sorted by dimensions under custom-size igniter.
Steel or ceramic
A steel igniter typically costs between 350 and 800 kr. and is the type that the vast majority of stoves in the range are designed for. A ceramic igniter reaches ignition temperature more quickly and generally lasts longer, but costs more and only fits where the mounting and dimensions match. The safest choice is the type already fitted in the stove, and if you are unsure about the type, all variants are collected under igniters.
