Payne PG95ESA Error Code 13: Limit Circuit Lockout

What Does Code 13 Mean?

Status code 13 (one short flash followed by three long flashes) is a limit circuit lockout. The furnace enters it when the high-temperature limit switch or the flame rollout switch stays open for more than 3 minutes. This is a safety shutdown: when air isn't moving heat away from the heat exchanger fast enough, temperatures climb, the limit opens, and gas to the burners is cut.

On this single-stage PG95ESA the burners fire at one fixed rate, so adequate airflow across the heat exchanger is what keeps operating temperature in range. The overwhelmingly common trigger is a dirty or clogged air filter; blocked or closed supply and return vents do the same thing. Less commonly a blower motor problem or wrong blower speed setting reduces airflow, and a tripped flame rollout switch points to a combustion or venting issue rather than plain airflow.

Code 13 is the lockout that follows code 33 (limit circuit fault). Code 33 is the active fault while the limit or flame rollout switch is open; once that switch has stayed open longer than 3 minutes, the control escalates to this 13 lockout. It will auto-reset after 3 hours, but resetting without fixing the airflow cause only starts the cycle over.

What You'll Notice

• The furnace has gone quiet and stays off, with no heat for an extended period while the control holds the lockout for about 3 hours
• The amber LED flashes one short flash followed by three long flashes (code 13)
• Before locking out, the burners shut off while the blower kept running to shed heat, and the supply air turned cool
• Rooms grow noticeably colder because the furnace has stopped cycling
• In some cases a flame rollout switch with a small manual-reset button has tripped, which a technician must reset only after finding the cause

Common Causes

How to Fix It: Replace the Air Filter and Restore Airflow

What You'll Need

• Replacement air filter (correct size for your system) 🛒 Find at FiltersFast · 🛒 Find at Amazon
• Flashlight

Steps

1. Turn off electrical power at the breaker and shut off the gas supply valve Set the furnace circuit breaker to OFF and turn the manual gas shutoff valve to OFF (handle perpendicular to the pipe). If you smell gas, leave immediately and call your gas company.
2. Check and replace the air filter Remove the filter from the return duct or the furnace filter slot. If it is visibly dirty, clogged, or more than about 3 months old, replace it with a new filter of the correct size. Make sure the airflow-direction arrow points toward the furnace.
3. Open every supply and return vent Walk through each room and confirm all supply registers and return grilles are fully open and not blocked by furniture, rugs, or curtains. Even a few closed vents can restrict airflow enough to overheat this single-stage furnace.
4. Look at the blower area for dust buildup With the power still off, look through the blower access opening for heavy dust on the blower wheel, which reduces airflow. Do not disassemble or attempt to rebalance the wheel — note anything abnormal for a technician.
5. Restore gas and power, then test Turn the gas valve to ON and the breaker to ON. The control may take up to 3 hours to auto-reset, or you can clear it by cycling power (off 30 seconds, then on). Set the thermostat to call for heat and watch a full cycle.

When to Call a Professional

Contact a licensed HVAC technician if:

• Code 13 returns after replacing the filter and opening all vents
• The flame rollout switch has tripped (a manual-reset button that must be reset only after the combustion cause is found)
• The blower doesn't seem to run at full speed or makes unusual noises
• The furnace overheats repeatedly even with a clean filter and open ductwork

✓ Verified against manufacturer service manual — March 2026