Navien Error Code E238: Abnormal recirculation pump operation ● The pump is turned ON. ● Water flow is N
Severity
Warning
Type
digital display
Estimated repair cost:$100 — $350(parts + labor)
Warning: The Navien tankless water heater has detected a problem with the recirculation pump and has locked out. You will not have hot water until this is resolved.
How to Fix Navien Code E238
Step 1: Check that all valves in the recirculation loop are fully open. Sometimes a partially closed valve can restrict flow.
Step 2: Try power cycling the Navien unit by turning it off and then back on. This can sometimes clear a temporary error.
Step 3: If the problem persists, contact a qualified HVAC technician to diagnose and repair the issue.
How to Reset Navien Code E238
Turn off the unit using the power button on the front panel.
Turn off the gas supply valve.
Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
Restore power at the breaker, then open the gas valve.
Turn the unit back on. If the error returns, the underlying issue needs repair.
What does E238 mean?
The Navien E238 error code indicates an issue with the recirculation pump's operation. Specifically, the unit detects that the pump is running, but it's not sensing the expected water flow. This is a problem because Navien tankless units rely on proper water flow to heat water efficiently and safely. Without adequate flow, the unit can overheat, leading to potential damage or safety risks. The recirculation pump is designed to keep hot water readily available at your fixtures, and this error means that system is not working as intended.
Abnormal recirculation pump operation ● The pump is turned ON. ● Water flow is NOT detected.
This error occurs when the sensor on the furnace for recirculation pump operation does not operate properly. ● Turn off the furnace, turn it on again, and check if the furnace operates properly. ● If the furnace is continuously inoperable, contact Technical Support at 1-800-519-8794.