Bryant 355MAV Error Code 13: Limit Circuit Lockout
What Does Code 13 Mean?
Status code 13 on the Bryant 355MAV means the limit switch or flame rollout switch has been open for longer than 3 minutes, or the furnace has tripped the high-heat limit 10 successive times. The control board locks out the furnace to prevent damage from sustained overheating, and it will automatically reset after 3 hours.
The limit switch is a safety device that opens when the air temperature inside the furnace gets too high, which almost always means airflow is restricted. The most common restriction is a dirty or clogged air filter, followed by blocked return air vents (furniture pushed against them, closed dampers, etc.). When airflow is restricted, heat builds up in the heat exchanger faster than the blower can remove it, triggering the limit switch.
If the flame rollout switch has tripped, that is a more serious condition — it means flames are escaping the combustion chamber. The flame rollout switch requires manual reset (a small button on the switch itself). If you find the rollout switch tripped, do not simply reset it and ignore the problem; call a technician to inspect the heat exchanger and burner assembly.
Common Causes
How to Fix It: Check Air Filter and Return Air Vents
What You'll Need
- Replacement air filter (same size as current filter)
- Flashlight
Steps
- Turn off power at the breaker or power switch and shut off the gas supply valve Locate your electrical panel and turn the furnace breaker to OFF. Find the gas shutoff valve on the gas line leading to the furnace and turn it to the closed (perpendicular to the pipe) position. If you smell gas, leave immediately and call your gas company.
- Locate and inspect the air filter The air filter on the 355MAV is typically located in the blower compartment or in the return air duct near the furnace. Slide the filter out and hold it up to a light. If you cannot see light through it, or if it is visibly coated in dust and debris, it needs to be replaced.
- Replace the air filter if dirty Insert a new filter of the same size and type. Make sure the airflow direction arrow on the filter frame points toward the furnace (toward the blower). A severely clogged filter is the single most common cause of limit circuit lockouts.
- Check all return air vents and supply registers Walk through your home and make sure all return air grilles and supply registers are open and unobstructed. Move any furniture, rugs, or curtains that may be blocking them. Every blocked vent reduces airflow through the furnace.
- Restore power and gas, then wait for auto-reset Turn the gas supply valve back to open (parallel to the pipe) and turn the breaker back ON. The control board will auto-reset after 3 hours from the lockout, or you can reset it immediately by turning the furnace power switch OFF, waiting 30 seconds, and turning it back ON.
When to Call a Professional
Contact a licensed HVAC technician if:
- Code 13 returns after replacing the air filter and confirming all vents are open
- The flame rollout switch has tripped (requires manual reset button on the switch)
- You hear unusual noises from the blower area suggesting a loose blower wheel
- The furnace repeatedly trips the limit on high-heat only
- You notice the blower running but producing very little airflow