Hello, I have a problem with how lon hot surface igniter runs. Nordeyne spec is 30 seconds but mine runs 7 seconds then furace lights I have changed ignitor first no change then board and it ran 30 seconds for a couple of times then back to seven . Please help

Rick,
What is the problem that you are trying to fix?

The HSI is used to light the furnace. If the furnace is lighting after 7 seconds, I don't see a problem. Once the furnace lights, I would think the control board would turn off the HSI since it has done its job. The 30-second Nordyne spec is probably a maximum value. If the furnace doesn't light in 30 seconds, the controller will shut everything down with an error.

Please elaborate if you think something is not correct.
WallyH

Hello, I just thought it should fire ignitor for 30 second but it does run a hell of a lot quieter now that I have change circuit board. Thank you for telling me it can fire for less time .