Carrier Error Code 13: Limit/Rollout Fault

Severity
Critical
Type
led blink pattern
Where to look
sight glass
Estimated repair cost: $75 — $200 (parts + labor)
Warning: A Carrier 13 error indicates a limit switch or rollout switch has tripped, potentially due to a dangerous condition. Shut down the furnace immediately and call a qualified technician.

LED Blink Pattern

1 short blink, 3 long blinks.

How to Fix Carrier Code 13

  1. Step 1: Turn off the furnace immediately at the breaker.
  2. Step 2: Check and replace your air filter if it's dirty.
  3. Step 3: Ensure all vents are open and not blocked by furniture.
  4. Step 4: Call a qualified HVAC technician to inspect the furnace.

How to Reset Carrier Code 13

  1. Turn off the furnace power switch, usually located on or near the unit.
  2. Turn off the circuit breaker for the furnace. Wait 30 seconds.
  3. Restore power at the breaker and flip the furnace switch back on.
  4. Set the thermostat to call for heat. If the error code returns after 2-3 ignition attempts, the fault requires repair.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Carrier Error Code 13 Mean?

The Carrier error code 13, often displayed as a blinking LED pattern, signifies a 'Limit/Rollout Fault'. This means that either a limit switch or a rollout switch within your furnace has been triggered. These switches are safety devices designed to shut down the furnace when it detects potentially dangerous conditions like overheating or a flame where it shouldn't be. A limit switch monitors the furnace's internal temperature, and if it gets too hot, the switch opens, cutting off the gas supply. A rollout switch detects flames outside the normal burner area, indicating a potentially hazardous situation. Because this code indicates a potential safety issue, it's important to address it promptly. Continuing to run the furnace with this error could lead to equipment damage or, more seriously, a fire or carbon monoxide poisoning. Do not attempt to bypass any safety switches.

Common Causes

  • Blocked or dirty air filter restricting airflow and causing overheating.
  • Closed or blocked vents restricting airflow.
  • Faulty limit switch.
  • Flame rollout due to a cracked heat exchanger or blocked burner.
  • Failed blower motor not moving enough air.

Diagnostic Steps

If... Check Expected
Furnace is locked out and displaying error code 13. Visually inspect the burner area for signs of flame rollout (soot, melted wires). No signs of flame rollout.
No signs of flame rollout are present. Using a multimeter, test the continuity of the limit switch. (Should be closed under normal conditions). Continuity present (closed switch).
Limit switch is open (no continuity). Check the temperature rise across the furnace. (Supply vs. Return air). Temperature rise within the manufacturer's specified range (typically 30-60°F).

Applicable Carrier Models

Replacement Parts

Part OEM Number Est. Cost Where to Buy
Limit Switch KH42WZ008 — Find Part
Rollout Switch — — —
Blower Motor — — —

Related Codes on Same Models

Other codes that affect the same Carrier model families as 13.

Code Description Severity
12 Blower On After Power Up Warning
14 Ignition Lockout Critical
21 Gas Heating Lockout Critical
22 Abnormal Flame Critical
23 Pressure Switch Fault Warning
24 Secondary Voltage Fuse Warning
31 High Stage Pressure Fault Warning
32 Low Flame Sense Warning
33 Limit/Rollout Switch Lockout Critical
34 Ignition/Flame Sense Fault Warning