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
Check if the boiler's reset button has popped out. If so, press it gently to reset the boiler.
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.
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
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 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.