Rheem R802VA07542117MSA Error Code A022_F: Main Limit Switch Open

What Does Code A022_F Mean?

Fault code A022_F on the Rheem R802VA is the alarm-level version of the main limit switch open fault. It indicates the limit switch has been open for more than 150 seconds continuously, which the control board interprets as a dead blower condition. The furnace enters a one-hour safety lockout.

Unlike the T022_F troubleshooting code (which indicates a brief limit trip), A022_F means the furnace has been overheating for an extended period because air is not moving through the system. The 150-second threshold is specifically designed to identify blower motor failure — if the blower were running even weakly, it would typically cool the heat exchanger enough to close the limit switch sooner.

While a severely clogged air filter can contribute to this condition, the most common cause is a blower motor that has stopped running entirely or a failed blower motor capacitor. The furnace will attempt to restart after the one-hour lockout expires.

Common Causes

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

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. Check and replace the air filter Remove the air filter. If it is severely clogged or has not been changed in many months, replace it immediately. A completely blocked filter can restrict enough airflow to trigger this fault even with a working blower.
3. Check if the blower wheel spins freely With the power off, look through the blower access panel. Try to gently spin the blower wheel by hand. If it is stuck, seized, or very difficult to turn, the motor bearings have likely failed and need professional replacement.
4. Verify all vents are open throughout the home Walk through every room and open all supply registers and return grilles. Remove any furniture or items blocking vents.
5. Restore power and gas, then test Turn the gas supply valve to ON and flip the circuit breaker to ON. Wait for the lockout to expire (up to 1 hour) or cycle the power off for 30 seconds and back on to reset. When the furnace starts, 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 when the furnace calls for heat
• The blower wheel does not spin freely by hand
• The A022_F lockout returns even after replacing the air filter
• You hear humming but the blower does not spin up
• The blower motor makes grinding or squealing noises

✓ Verified against manufacturer service manual — March 2026