Navien Error Code E353: APS Sensor Open/Short

Severity
Warning
Type
digital display
Where to look
front panel
Estimated repair cost: $75 — $200 (parts + labor)
Warning: Your Navien boiler has detected an issue with the APS (Air Pressure Switch) sensor, which could lead to system damage if not addressed.

How to Fix Navien Code E353

  1. Check if the boiler's reset button has popped out. If so, press it gently to reset the boiler.
  2. Listen for any unusual noises coming from the boiler. If you hear any, turn off the power to the boiler at the circuit breaker and contact a professional HVAC technician.
  3. When to call a pro: Always if you're not comfortable performing any checks or if the reset button doesn't work.

How to Reset Navien Code E353

  1. Turn off the unit using the power button on the front panel.
  2. Turn off the gas supply valve.
  3. Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
  4. Restore power at the breaker, then open the gas valve.
  5. Turn the unit back on. If the error returns, the underlying issue needs repair.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Navien Error Code E353 Mean?

The E353 error on your Navien boiler indicates that the Air Pressure Switch (APS) sensor is either open or shorted. This sensor is responsible for monitoring the air pressure within the boiler to ensure safe operation. If the sensor is open, it's not sending any signal to the control board, and if it's shorted, it's sending a constant signal. Either condition can cause the boiler to malfunction or shut down.

Common Causes

  • A faulty Air Pressure Switch (APS) sensor
  • Damaged wiring or connections to the APS sensor
  • Air pressure in the boiler that's out of the normal range

Diagnostic Steps

If... Check Expected
Boiler is not operating Reset button status Button should be in, if not, try resetting it
Boiler is operating Air pressure in the boiler Between 0.5 to 1.5 inches W.C (water column)

Applicable Navien Models

Source Documentation

Referenced in 5 official Navien technical manuals.

ManualPageReasonAction
NFB-H Installation & Operation Manual116Water Pressure SensorCheck WPS.
Navien NCB-H Installation & Operation Manual129Water Pressure SensorContact technical support at 1-800-519-8794.
Navien NFB-H Installation & Operation Manual116Water Pressure SensorCheck WPS.
Navien NFC-H Installation & Operation Manual127Abnormal operation: water pressure sensorAuto RESET
Navien NHB-H Installation & Operation Manual119Water Pressure SensorCheck WPS.

Replacement Parts

Part OEM Number Est. Cost Where to Buy
Air Pressure Switch (APS) Sensor 200-10002-00

Related Codes on Same Models

Other codes that affect the same Navien model families as E353.

Code Description Severity
E001 Ignition Failure Warning
E003 Abnormal Ignition Warning
E004 False Flame Detection Warning
E012 Flame Loss Warning
E016 Overheating Warning
E030 Exhaust Overheat Sensor Warning
E031 Inlet Thermistor Open/Short Warning
E046 Outlet Thermistor Open/Short Warning
E047 DHW Thermistor Open/Short Warning
E060 Fan Motor Abnormality Warning