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Weil McLain HE II Boiler Image 10

The red arrow is pointing to the hot surface igniter HSI yours may have been replaced with one that does not look like this one. The HSI gets cherry red and ignites the gas when the gas valve opens. This also sends a signal back to the control module indicating there is a flame, in other applications a separate flame sensor probe is used to verify there is a flame.

Hsi Hot water boiler



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