Payne PG8MAA Error Code Limit Circuit Lockout: Limit Circuit Lockout

What Does Code Limit Circuit Lockout Mean?

Status code 13 on the Payne PG8MAA indicates a limit circuit lockout. This means the limit switch, draft safeguard switch, flame rollout switch, or blocked vent switch (if installed) has been open for longer than 3 minutes. The control board locks out the furnace to prevent damage from sustained overheating, and it will automatically reset after 3 hours.

The most common trigger is restricted airflow caused by a dirty or clogged air filter. When airflow through the furnace is restricted, heat builds up in the heat exchanger faster than the blower can remove it, and the limit switch opens to protect the system. Blocked or closed return air vents throughout the house have the same effect.

If the flame rollout switch or blocked vent safety switch (BVSS) tripped, these require manual reset — they have a small button you must press to reset them. However, if either of these switches has tripped, it indicates a potentially dangerous condition (flames escaping the combustion chamber or a blocked vent) that should be inspected by a professional before simply resetting the switch.

Common Causes

How to Fix It: Check Air Filter and Vents

What You'll Need

• Replacement air filter (same size as current filter)
• Flashlight

Steps

1. 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.
2. Locate and inspect the air filter The air filter on the PG8MAA is typically in the blower compartment or the return air duct near the furnace. Slide it out and hold it up to a light. If you cannot see light through it, or if it is visibly caked with dust, it needs to be replaced.
3. Replace the air filter if dirty Install 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 on this model.
4. Check all return air vents and supply registers Walk through every room and confirm all return air grilles and supply registers are open and unobstructed. Move furniture, rugs, or curtains that may be blocking airflow. Closing too many registers in unused rooms reduces total system airflow and can cause overheating.
5. Restore power and gas, then wait for auto-reset Turn the gas supply valve back to open (parallel to the pipe). Turn the breaker back ON. The control board will auto-reset after 3 hours from the lockout, or you can reset it immediately by cycling the furnace power switch OFF for 30 seconds, then 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 (it has a manual reset button)
• The blocked vent safety switch (BVSS) has tripped
• You hear unusual noises from the blower area suggesting a loose blower wheel or failing motor
• The blower runs but produces very little airflow from the registers
• The furnace overheats repeatedly in a short period