Rheem R802VA07542117MSA Error Code A111_F: One-hour Lockout: Main Limit Switch

What Does Code A111_F Mean?

Fault code A111_F on the Rheem R802VA indicates a one-hour lockout triggered by repeated main limit switch trips. The control board has determined a dead blower condition exists — the main limit circuit has been open for more than 150 seconds, meaning the furnace has been dangerously overheating without adequate airflow.

This is one of the more serious overheating codes. It means the furnace has not just tripped the limit switch briefly (T022_F) or sustained an extended trip (A022_F), but has escalated to a full one-hour lockout to protect the heat exchanger and other components from heat damage.

The most common cause is a failed blower motor that is no longer circulating air through the system. A severely dirty air filter can contribute, but at this severity level the blower motor or its capacitor has usually failed or is failing. The furnace will attempt to restart after the one-hour lockout period.

Common Causes

How to Fix It: Check the Air Filter and Blower Motor

What You'll Need

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

Steps

1. Turn off power at the breaker or power switch AND shut off the gas supply valve Locate the furnace circuit breaker and flip it to OFF. Turn the gas shutoff valve to the OFF position (perpendicular to the pipe). If you smell gas, leave immediately and call your gas company.
2. Replace the air filter immediately Remove the air filter. Even if it does not look extremely dirty, replace it with a new one to eliminate airflow restriction as a factor. Make sure the airflow direction arrow points toward the furnace.
3. Open all supply and return vents Walk through every room and ensure all supply registers and return grilles are fully open and unblocked. Remove any furniture, curtains, or rugs covering vents.
4. Check if the blower motor spins freely With the power off, look through the blower access panel. Try to gently spin the blower wheel by hand. If it does not spin freely, is seized, or makes grinding sounds, the motor has likely failed.
5. Restore power and gas, then test after lockout clears Turn the gas supply valve to ON and flip the circuit breaker to ON. Wait for the one-hour lockout to expire, or cycle the power off for 30 seconds and back on. When the furnace attempts to start, listen for the blower motor and feel the supply vents for airflow.

When to Call a Professional

Contact a licensed HVAC technician if:

• The blower motor does not start or sounds abnormal
• The blower wheel does not spin freely by hand
• The A111_F lockout recurs even with a new filter and open vents
• You hear a humming sound from the motor but the blower does not spin
• The furnace has been cycling between A022_F and A111_F repeatedly

✓ Verified against manufacturer service manual — March 2026