E352 🟡 Repair Required
Navien Error Code E352: APS Sensor Abnormality
⚠️ Your Navien boiler has detected an issue with the Aquastat Pressure Switch (APS) sensor, which could lead to system malfunction. It's safe to use, but needs professional attention.
How to Fix Navien Code E352
- Check your boiler's pressure gauge. If it's above 30 PSI, you may have excess pressure in the system.
- If the pressure is too high, you can bleed the system's air using the bleed valve, but be careful not to lose too much water.
- If the pressure is normal, or if bleeding the system doesn't resolve the issue, contact a professional HVAC technician
What Does Navien Error Code E352 Mean?
The E352 error on your Navien boiler indicates an abnormality with the Aquastat Pressure Switch (APS) sensor. This sensor is responsible for monitoring the water pressure in your heating system. When it detects an issue, it sends an error signal to the boiler's control board, displaying the E352 code. While your boiler is still operational, it's important to have this issue addressed by a professional to prevent potential system damage or reduced efficiency.
Common Causes of Navien Code E352
- A faulty Aquastat Pressure Switch (APS) sensor
- Incorrect water pressure in the system
- Air or other non-compressible substances in the system
- Wiring issues between the APS sensor and the boiler's control board
Applicable Navien Models
Source Documentation
This error code is documented in 5 official Navien technical manuals.
NFB-H Installation & Operation ManualPage 116
ReasonHigh Water Pressure
ActionCheck water pressure.
Navien NCB-H Installation & Operation ManualPage 129
ReasonHigh Water Pressure
ActionContact technical support at 1-800-519-8794.
Navien NFB-H Installation & Operation ManualPage 116
ReasonHigh Water Pressure
ActionCheck water pressure.
Navien NFC-H Installation & Operation ManualPage 127
ReasonHigh water pressure
ActionAuto RESET
Navien NHB-H Installation & Operation ManualPage 119
ReasonHigh Water Pressure
ActionCheck water pressure.
Need a Pro to Fix Navien Code E352?
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 E352
Aquastat Pressure Switch (APS) Sensor OEM: Navien 9010140000