My Lennox is saying the primary/secondary limit switch is open. No heat

Lennox Primary Limit Switch Open. Limit Switch Open Lennox Furnace at Larry Thielen blog The limit switch will trip typically when the temperature rise exceeds the range listed on the rating plate I think because the faults are so different, it's something else.

I have reset the indoor (using switch on unit) and outdoor (using breaker panel) units Gas and Oil Home Heating Furnaces - Primary/Secondary limit switch open for Lennox G26Q2-50-4 - My furnace was blowing cold air so I looked the diagnostic light to determine that it was displaying the primary/secondary limit switch open message

Lennox 10M63 Limit Switch

Limit controls are in the fan compartment and you need to remove the venting etc My furnace will run between a few hours to a few days but eventually, it'll stop working Not something I can walk you thru over the internet w/o other problems occuring

Lennox G51MP Elite Series my furnace is saying the primary. Looks like a counterflow/down flow G24 which is a VERY nasty furnace to work on The limit switch will trip typically when the temperature rise exceeds the range listed on the rating plate

I have a lennox model c2351fc1 primary/secondary limit switch open. When trying to turn on heat on my Lennox SL280UH070V36A-03, I get a fault called GF primary limit switch open Thermostat is fine I think Contractor's Assistant: Do you plan on doing the work yourself? Customer: If I can Contractor's Assistant: Anything else we should.