Hot Surface Ignition
The hot surface igniter is the most commonly used electronic ignition system used today. The reason is they are reliable, inexpensive and the electronic controls they require are also less expensive. All they require is a flame sensor to detect the igniter glow and open the main burner valve.
The hot surface igniter works like a light bulb filament, except here, we want the heat from the element, not the light. The hot surface igniter is usually made from a material like silicon carbide or nitride and as electricity passes through the igniter, it will glow red hot.
Under normal conditions the igniter should last for 3-5 years. However, it will eventually crack and need to be replaced, quicker if the oils from your skin get on the element by improper handling.
These hot surface igniters are between $25 to $50 depending upon the model of furnace you have. I strongly recommend you keep a spare on hand. Just like a light bulb, the filament does not last forever and these igniters fail. As Murphy's Law will have it, the igniter will fail when it is at night or on a weekend and you can't easily get a spare.
We now need to take a look at some of the associated parts of the electronic ignition furnace.
Possible Reasons for HSI Failure
- Premature failure due to improper handling (oil from skin got onto element)
- Improper igniter
- End of normal usage life cycle (keep replacement on hand)
- Electric current in the home is too high (over 125 VAC)
- Dirty filter or squirrel cage.
