Rheem HVAC Error Code 19: How to Fix It

Q: What does Rheem error code 19 mean?

Rheem error code 19 means the outdoor coil temperature sensor has an open circuit. The control board is not receiving a valid resistance signal from the sensor, which is usually caused by a broken wire, loose connector, or a failed sensor probe.

Q: Can I still run my Rheem HVAC with error code 19?

It is not recommended. Without a functioning outdoor coil sensor, your system cannot properly monitor coil temperatures, which can lead to short cycling, inefficient operation, or damage to the compressor. The system may lock itself out as a safety measure. Address the issue promptly.

Q: How much does it cost to replace a Rheem outdoor coil sensor?

The sensor part itself is typically inexpensive, usually ranging from $10 to $40 depending on the model. If you hire an HVAC technician, you can expect to pay an additional $75 to $150 in labor, bringing the total to roughly $85 to $200 for a professional repair.

Q: How do I reset the error code 19 on my Rheem HVAC after fixing it?

Many Rheem systems will automatically clear the error code once the sensor issue is resolved and power is restored. If the code persists, try turning the system off at the thermostat for 30 seconds and then back on. Some models require a full power cycle at the breaker. Consult your specific Rheem model's owner manual for the exact reset procedure.

Q: Could a dirty or iced-over coil cause error code 19 on a Rheem unit?

A dirty or frozen coil does not directly cause error code 19, which is specifically an open sensor circuit fault. However, a heavily iced coil could physically damage the sensor wire or probe over time. If you notice ice buildup on your outdoor unit, that is a separate issue (such as low refrigerant or airflow restriction) that should also be investigated.

Abstract

Rheem HVAC Error Code 19 indicates that the outdoor coil temperature sensor (also called the outdoor coil thermistor) has an open circuit, meaning the control board is not receiving a valid signal from the sensor. This typically happens when the sensor wire is broken, the connector is loose or corroded, or the sensor itself has failed. Until this issue is resolved, your system may run inefficiently, short-cycle, or shut down entirely to protect itself from damage.