My Lennox is saying the primary/secondary limit switch is
From https://www.justanswer.com/ythi JustAnswer Customer: My Lennox is saying the primary/secondary limit switch is open. JustAnswer Customer: No heat Pearl Wilson: Assistant: Did you double-check the thermostat’s settings? Pearl Wilson: Assistant: And what about the filters? JustAnswer Customer: Just changed the filter and it was pretty bad. JustAnswer Customer: Thermostat is fine I think Pearl Wilson:…