Rheem Error Code A091: PCB Communication Error

Severity
Warning
Type
digital display
Where to look
front panel
Estimated repair cost: $300 — $650 (parts + labor)
Warning: Your Rheem HVAC system has a PCB communication error, which may cause system malfunctions. It's safe to troubleshoot, but call a professional if needed.

How to Fix Rheem Code A091

  1. Check and tighten all electrical connections
  2. Inspect wiring and connectors for damage or corrosion
  3. Try resetting the system by turning off the power at the breaker for 30 seconds and then turning it back on

How to Reset Rheem Code A091

  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 A091 mean?

The Rheem A091 error code indicates a communication issue between the main PCB (Printed Circuit Board) and other system components. This could be due to a faulty wire, connector, or the PCB itself. The system may not operate correctly or might display other error codes as a result.

Affected Models

Replacement Parts

PartOEM NumberEst. Cost
Main PCB RHEEM-301435 —
Wiring harness — —

Related Codes on Same Models

CodeDescriptionSeverity
A001 Ignition Failure Warning
A003 Abnormal Ignition 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