Rheem Error Code 11: Rheem Code 11 - No Ignition

Severity
Critical
Type
digital display
Estimated repair cost: $75 — $200 (parts + labor)
Warning: This error indicates a failure to ignite the gas, which could lead to a dangerous gas buildup. Shut down the unit immediately and call a qualified technician.

How to Fix Rheem Code 11

  1. Step 1: Ensure the gas supply to the unit is turned on. Check the shut-off valve on the gas line leading to the water heater.
  2. Step 2: Reset the unit by turning it off and then back on. See if the error clears. If it returns, do not continue to reset it.
  3. Step 3: Call a qualified HVAC technician or plumber to diagnose and repair the problem. Do not attempt to troubleshoot gas-related issues yourself.

How to Reset Rheem Code 11

  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 11 mean?

Rheem error code 11 signals that your tankless water heater attempted to ignite the burner but failed. This means the unit went through its startup sequence, including the fan starting and the igniter sparking, but the main burner flame didn't establish itself. The water heater will typically try a few times before locking out on this error. This is a critical safety issue because unburned gas can accumulate, creating a risk of explosion or carbon monoxide poisoning. It's important to address this problem right away to ensure your safety and the proper operation of your water heater.

Affected Models

Replacement Parts

PartOEM NumberEst. Cost
Flame Sensor AP14914
Igniter AP14838
Gas Valve

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