Rheem Error Code A003: Abnormal Ignition

Severity
Warning
Type
digital display
Where to look
front panel
Estimated repair cost: $100 — $250 (parts + labor)
Warning: Your Rheem HVAC system has encountered an abnormal ignition issue. It's safe to troubleshoot, but it's recommended to call a professional for repair.

How to Fix Rheem Code A003

  1. Step 1: Check if the gas valve is open and the gas supply is on.
  2. Step 2: Inspect the area around the furnace for any gas leaks. If you smell gas, evacuate immediately and call your gas company.
  3. Step 3: If no gas leak is detected, call a professional HVAC technician for repair.

How to Reset Rheem Code A003

  1. Turn off the unit using the power button on the front panel.
  2. Turn off the gas supply valve.
  3. Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
  4. Restore power at the breaker, then open the gas valve.
  5. Turn the unit back on. If the error returns, the underlying issue needs repair.

What does A003 mean?

The A003 error on your Rheem HVAC system indicates an abnormal ignition issue. This could mean that the system is having trouble igniting the burner or keeping it lit. This is likely due to a problem with the ignition system or the gas supply. Don't worry, it's safe to troubleshoot, but it's recommended to call a professional for repair.

Affected Models

Replacement Parts

PartOEM NumberEst. Cost
Ignition Control Module RHEEM 80-00012710 —
Igniter RHEEM 80-00012700 —
Flame Sensor RHEEM 80-00012720 —

Related Codes on Same Models

CodeDescriptionSeverity
A001 Ignition Failure Warning
A004 False Flame Detection Warning
A008 Exhaust Temperature High Warning
A011 No Flame Detected Warning
A021 Over-Temperature Warning
A031 Inlet Thermistor Open/Short Warning
A041 Outlet Thermistor Open/Short Warning
A043 Water Level Error Warning
A051 Fan Motor Abnormality Warning
A052 Fan Motor Speed Error Warning