Appliance Diagnostic

Bryant Furnace Code 13 - Limit Circuit Lockout

Code 13 indicates primary limit switch opened 3 consecutive times in a single heat call, putting system into temporary auto-lockout.

What Caused This Error?

The control system reports 13 when the monitored condition described by the error code is outside the expected operating range. In this case, the most likely trigger is closed supply registers. Other common contributors include extremely clogged furnace filter and failing indoor blower motor.

Step-by-Step Diagnostic Check

  1. Replace furnace filter immediately.
  2. Open all home floor vents and duct dampers.
  3. Reset main power disconnect for 30 seconds.
  4. Replace primary thermal limit switch.
Most Likely Replacement Part

Primary Thermal Limit Switch

OEM Part #: MODEL-SPECIFIC

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