Rheem Error Code A001: Ignition Failure

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 ignition failure. It's safe to operate, but it needs professional attention.

How to Fix Rheem Code A001

  1. Step 1: Turn off your HVAC system at the thermostat.
  2. Step 2: Check if the error persists after turning the system back on. If it does, it's time to call a professional.
  3. Step 3: In the meantime, ensure the area around your HVAC unit is clear and well-ventilated.

How to Reset Rheem Code A001

  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.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Rheem Error Code A001 Mean?

The A001 error code on your Rheem HVAC system indicates that the ignition system isn't functioning correctly. This could be due to a faulty ignition control module, a problem with the igniter, or an issue with the gas valve. The system is designed to protect itself from potential hazards, so it's displaying this error and may not be operating at full capacity.

Common Causes

  • Faulty ignition control module
  • Defective igniter
  • Problem with the gas valve

Diagnostic Steps

If... Check Expected
The system is not igniting at all Inspect the igniter for any visible damage or signs of wear A clean, undamaged igniter
The igniter glows but the system doesn't light Measure the voltage at the igniter terminals using a multimeter 120V AC

Applicable Rheem Models

Replacement Parts

Part OEM Number Est. Cost Where to Buy
Ignition Control Module RHEEM 357090
Igniter RHEEM 357080

Related Codes on Same Models

Other codes that affect the same Rheem model families as A001.

Code Description Severity
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
A053 Fan Motor Open Circuit Warning
A054 Fan Motor Overcurrent Warning
A055 Fan Motor Locked Warning
A095 DIP Switch Error Warning