Rinnai Error Code 55: Rinnai Code 55 - False Fire Detection
How to Fix Rinnai Code 55
- Step 1: Immediately turn off the gas supply to the Rinnai unit at the gas shut-off valve.
- Step 2: Turn off the electrical power to the unit at the breaker.
- Step 3: Contact a qualified HVAC technician or Rinnai-certified service provider to inspect and repair the unit. Do not attempt to troubleshoot or repair the unit yourself.
What Does Rinnai Error Code 55 Mean?
Rinnai error code 55 indicates that the unit's flame sensor is detecting a flame when it shouldn't be. This can happen either before a call for heat, or after the unit is already off. This is a critical safety issue because it could mean that gas is leaking into the combustion chamber and creating a risk of uncontrolled ignition or carbon monoxide poisoning. It's important to address this immediately to prevent potential hazards and further damage to your Rinnai tankless water heater. Essentially, the unit 'thinks' it sees a flame when it shouldn't. The control board relies on the flame rod sensor to confirm the presence of a flame during normal operation. If the flame rod is sending the wrong signal, the control board can get confused and shut down the unit as a precaution.
Common Causes of Rinnai Code 55
- Defective flame sensor (rod)
- Faulty gas valve leaking gas into the combustion chamber
- Short circuit or wiring issue in the flame sensor circuit
- Problem with the main control board (PCB)
- Gas pressure too high
Applicable Rinnai Models
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This error requires immediate attention from a licensed HVAC technician. Do not attempt repair yourself.
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