Navien Error Code E515: Low Water Flow

Severity
Warning
Type
digital display
Where to look
front panel
Estimated repair cost: $150 — $350 (parts + labor)
Warning: Your Navien boiler has detected a low water flow issue, which could lead to system damage if not addressed.

How to Fix Navien Code E515

  1. Check your water supply pressure. It should be between 20-80 PSI. If it's too low, you may need to contact your water supplier.
  2. If you have recently installed a water softener or filter, ensure it's not causing a restriction in water flow.
  3. Contact a professional HVAC technician if you're unable to resolve the issue.

How to Reset Navien Code E515

  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 E515 mean?

The E515 error on your Navien boiler indicates that the water flow rate is lower than normal. This could be due to a partial blockage in the system, a faulty flow sensor, or an issue with your water supply. It's important to address this issue promptly to prevent potential damage to your boiler.

Affected Models

Source Documentation

ManualPageReasonAction
NFB-H Installation & Operation Manual 116 Abnormal PCB Check PCB connections.
Navien NCB-H Installation & Operation Manual 130 Abnormal PCB ● Ensure that the electrical cord is properly grounded. ● Reset the boiler from the front panel.
Navien NFB-H Installation & Operation Manual 116 Abnormal PCB Check PCB connections.
Navien NFC-H Installation & Operation Manual 127 Abnormal operation: PCB component Manual RESET Alarm
Navien NHB-H Installation & Operation Manual 119 Abnormal PCB Check PCB connections.
Navien NPF Installation & Operation Manual 127 Abnormal WD-PSS1 status This error occurs when there is abnormal operation in the main controller (PCB). ● If this error occurs continuously, contact Technical Support at 1-800-519-8794.

Replacement Parts

PartOEM NumberEst. Cost
Water Flow Sensor

Related Codes on Same Models

CodeDescriptionSeverity
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