Rheem tankless water heater error code 32 typically indicates an issue with the inlet thermistor or temperature sensor.
Table of Contents
- What does error code 32 mean on a Rheem tankless water heater?
- What usually causes Rheem error code 32 to appear?
- How can I fix Rheem error code 32 with quick checks?
- What are the next troubleshooting steps if the error persists?
- Which fix matches your specific Rheem water heater symptom?
- When should you stop troubleshooting and call a professional?
- What information should you have ready before calling support?
- How can you prevent error code 32 from coming back?
What does error code 32 mean on a Rheem tankless water heater?
Error code 32 on a Rheem tankless water heater indicates a problem with the inlet thermistor or its associated wiring.
The inlet thermistor measures the temperature of incoming cold water. When this sensor fails, gets disconnected, or sends an abnormal signal, the control board displays error code 32 to prevent incorrect heating operations.
- Inlet water temperature sensor is malfunctioning.
- Wiring harness to the thermistor is loose or damaged.
- Corrosion has built up on the sensor electrical connections.
- Control board is failing to read the thermistor input.
- Sensor is out of its calibrated resistance range.
What usually causes Rheem error code 32 to appear?
Error code 32 is most commonly caused by a loose wiring connection at the inlet thermistor or a failed sensor.
Over time, vibration from normal water heater operation can loosen electrical connectors. Additionally, mineral buildup or component aging can cause the thermistor itself to fail completely.
- Loose plug connecting the inlet thermistor to the main control board.
- Corroded pins inside the wiring harness connector.
- Faulty thermistor component requiring replacement.
- Damaged wiring due to pests or high heat exposure.
- Temporary electronic glitch requiring a system power reset.
How can I fix Rheem error code 32 with quick checks?
You can resolve temporary electronic glitches by performing a hard power reset on your water heater.
Before checking internal components, always ensure safety by turning off the power switch or disconnecting the electrical breaker to prevent shock hazards.
- Turn off the power switch on the water heater unit.
- Turn off the dedicated electrical breaker supplying power to the water heater.
- Wait at least five full minutes for all electrical components to discharge completely.
- Turn the electrical breaker back on.
- Turn the water heater power switch back on and check the display screen.
What are the next troubleshooting steps if the error persists?
Inspect the inlet thermistor wiring harness and check the sensor resistance using a multimeter.
If a power reset does not clear error code 32, you will need to inspect the physical components inside the unit. Always disconnect power before removing the front cover.
- Unplug the water heater or turn off the electrical breaker before removing the front panel.
- Remove the front metal cover by unscrewing the mounting screws.
- Locate the inlet water pipe and find the thermistor sensor mounted on it.
- Unplug the thermistor wire connector and check for corrosion, dirt, or moisture.
- Firmly reconnect the wiring plug to ensure secure contact.
- Restore power and test the water heater operation.
Which fix matches your specific Rheem water heater symptom?
Match your exact display behavior and component status to determine the appropriate repair action.
Different underlying causes require different corrective actions ranging from simple wiring adjustments to complete component replacement.
| Symptom | Likely cause / fix |
|---|---|
| Error appears intermittently | Loose wire connector; reseat wiring plug. |
| Error appears constantly | Failed sensor; replace inlet thermistor. |
| Corrosion on sensor pins | Moisture exposure; clean pins or replace harness. |
| Error remains after sensor replacement | Faulty control board; call a technician. |
When should you stop troubleshooting and call a professional?
Call a licensed technician if replacing the thermistor does not clear error code 32 or if gas lines are involved.
While basic sensor checks are manageable, electrical board diagnostics and internal gas component repairs require professional expertise to ensure safety and prevent property damage.
- Error code 32 remains visible after installing a new inlet thermistor.
- You notice frayed wiring or burnt areas on the main control board.
- You smell gas or suspect a gas valve malfunction near the unit.
- You are uncomfortable working around high-voltage internal electrical components.
What information should you have ready before calling support?
Gather your exact water heater model number, serial number, and a record of troubleshooting steps tried.
Having this information ready helps customer service or repair technicians diagnose the problem faster and verify warranty coverage for replacement parts.
- Complete model number printed on the rating label on the side of the unit.
- Serial number indicating the manufacture date and unit batch.
- Details of when error code 32 appears during water usage.
- List of actions you already performed, such as power resetting and checking wiring.
How can you prevent error code 32 from coming back?
Protect your water heater with regular maintenance, surge protection, and annual flushing.
Keeping your tankless water heater clean and protected from electrical surges minimizes sensor malfunctions and extends the overall lifespan of internal electronic components.
- Install a dedicated whole-house surge protector to safeguard sensitive electronic control boards.
- Flush the water heater heat exchanger annually to reduce mineral scale buildup.
- Inspect external wiring periodically for signs of looseness or pest damage.
- Ensure proper ventilation clearance around the appliance according to manufacturer instructions.
Frequently Asked Questions
Can I still use hot water when error code 32 is displayed on my Rheem unit?
When error code 32 is active, the water heater often locks out operation as a safety precaution to prevent overheating. You may experience cold or lukewarm water until the inlet thermistor issue is fully resolved by resetting the unit or replacing the faulty sensor.
Where is the inlet thermistor located inside a Rheem tankless water heater?
The inlet thermistor is located directly on the cold water inlet pipe near the bottom of the unit where water enters the system. You will need to remove the outer metal cabinet cover to access and inspect this specific sensor component.
Is error code 32 covered under the Rheem manufacturer warranty?
Warranty coverage for error code 32 depends on the age of your water heater and whether you registered the appliance after installation. Check your owner’s manual or visit the manufacturer support page to verify specific part warranty terms and labor coverage periods.
What multimeter reading should a healthy Rheem inlet thermistor show?
healthy thermistor shows a specific electrical resistance value measured in ohms that changes depending on the incoming water temperature. Exact resistance charts vary by model line, so consult the technical service manual for precise temperature-to-resistance specifications.
What should I do if error code 32 returns immediately after clearing it?
If error code 32 returns right away, it indicates a permanent hardware fault rather than a temporary glitch. You should inspect the wiring harness connection closely or prepare to replace the defective inlet thermistor sensor.
Bottom Line
Always turn off the electrical breaker before inspecting internal parts, and start by performing a simple power reset.
Sources
- Rheem owner’s manual
- Manufacturer support page
- Tankless water heater technical guide