High Limit Opening

charliechicago

I have a York condensing furnace that has a high limit auto reset that sits on the inducer motor housing that is opening. What is its function? What is its function vs the main high limit ? What would cause it to open ?

Thanks in advance.

Ironman

The furnace could be over fired, there could be a blockage in the vent, or the inducer could be going bad.

EBEBRATT-Ed

It's purpose is to trip on high flue temp. In addition to what @Ironman mentioned above check that your air filters are clean, and you have sufficient air flow and that the indoor blower motor is on the correct speed.

You could have a mouse nest or dead bird in the exhaust pipe.

charliechicago

Thanks for the responses

Ironman, is there a way to test if the inducer is going bad?

EBEBRATT-Ed, you're saying, with an air flow issue, it could trip before the main high limit?

EBEBRATT-Ed

It may or may not trip before the high limit. I would think the HL would trip first. I was throwing out some other possibilities.

As far as checking the inducer you could probably disconnect the flue pipe and look inside and see what the blades look like and spin it. Then start the furnace withe GAS SHUT OFF and see if the inducer sounds ok and blows air. I would check the flue pipe and inlet pipe for restriction before taking the inducer apart unless the inducer sounds bad

charliechicago

EBEBRATT-Ed Thank you !