Navien Error Code E352: APS Sensor Abnormality

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 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

  1. Check your boiler's pressure gauge. If it's above 30 PSI, you may have excess pressure in the system.
  2. 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.
  3. If the pressure is normal, or if bleeding the system doesn't resolve the issue, contact a professional HVAC technician

How to Reset Navien Code E352

  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.

What does 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.

Affected Models

Source Documentation

ManualPageReasonAction
NFB-H Installation & Operation Manual 116 High Water Pressure Check water pressure.
Navien NCB-H Installation & Operation Manual 129 High Water Pressure Contact technical support at 1-800-519-8794.
Navien NFB-H Installation & Operation Manual 116 High Water Pressure Check water pressure.
Navien NFC-H Installation & Operation Manual 127 High water pressure Auto RESET
Navien NHB-H Installation & Operation Manual 119 High Water Pressure Check water pressure.

Replacement Parts

PartOEM NumberEst. Cost
Aquastat Pressure Switch (APS) Sensor Navien 9010140000

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CodeDescriptionSeverity
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