E218 🟡 Repair Required
Navien Error Code E218: Bypass Servo Motor Failure
⚠️ Your Navien boiler has detected a failure in the bypass servo motor, which may impact system performance. Schedule a professional repair soon.
How to Fix Navien Code E218
- Step 1: Turn off the boiler at the main power switch to ensure safety.
- Step 2: Check if the bypass valve is stuck or obstructed. If it's easy to turn, try gently moving it back and forth. If it's stuck, do not force it and call a professional.
- Step 3: If the issue persists, call a licensed HVAC technician to diagnose and repair the problem.
What Does Navien Error Code E218 Mean?
The E218 error on your Navien boiler indicates a failure in the bypass servo motor. This motor is responsible for controlling the flow of water through the boiler's heat exchanger. When it fails, the boiler may not be able to maintain the correct water temperature, leading to inefficient heating. The error code will display on your boiler's digital display, and the unit will enter lockout mode to prevent further operation until the issue is resolved.
Common Causes of Navien Code E218
- Worn or faulty servo motor
- Obstruction in the water flow
- Incorrect motor wiring or connection issues
- Faulty control board or sensor
Applicable Navien Models
Source Documentation
This error code is documented in 6 official Navien technical manuals.
NFB-H Installation & Operation ManualPage 116
ReasonHeating Return Temp.Sensor
ActionCheck thermistor connector.
Navien NCB-H Installation & Operation ManualPage 129
ReasonHeating Return Temp.Sensor
ActionContact technical support at 1-800-519-8794.
Navien NFB-H Installation & Operation ManualPage 116
ReasonHeating Return Temp.Sensor
ActionCheck thermistor connector.
Navien NFC-H Installation & Operation ManualPage 127
ReasonAbnormal operation: heating return thermistor
ActionAuto RESET
Navien NHB-H Installation & Operation ManualPage 119
ReasonHeating Return Temp.Sensor
ActionCheck thermistor connector.
Navien NPF Installation & Operation ManualPage 126
ReasonAbnormal return water-temp sensor operation for lower limit
Need a Pro to Fix Navien Code E218?
A licensed HVAC technician can diagnose and fix this issue quickly.
Find a Licensed Tech Near You →Replacement Parts for Navien Tankless Water Heater Code E218
Bypass Servo Motor OEM: NAVIEN 30001400
Control Board OEM: NAVIEN 30001200