The high limit senses over  temperature  of the  furnace. If the high limit switch  is bad, the  furnace  should not fire. When the high limit switch  trips, the flame/heating element will be shut off and the blower will continue to run to clear the heat. The blower will continue to run until either the system is reset, or the  limit switch resets or is replaced.

We sell a supply of the most common limit switches. Call or come in to verify your matchup

Picture
3" Limit (Available in varied temperature limits)
Picture
Adjustable Limit Switches
Picture
Coleman/York/Evcon Fan Limit
Picture
Trane OEM Limit Switch
Picture
Roll out limit switch 300F
Picture
Coleman/York/Evcon OEM Limits