Green Flow Solution logo
Schedule Service

Troubleshooting code

Back to all NCB-H Series error codes

Navien NCB-H Series E615 troubleshooting

Abnormal operation: input and memory. Use this page to document the issue and prepare for service. GreenFlow should handle diagnosis for electrical, refrigerant, lockout, or recurring conditions.

Schedule Service +1 (857) 767-6414

What the code means

E615: Abnormal operation: input and memory

The Navien manual for this product family lists E615 as: Abnormal operation: input and memory.

System area
Controls / communication
Service level
Service recommended

Safe checks before calling

  • Record the exact Navien code, whether the unit is locked out, and when the code appeared.
  • Confirm thermostat, controller, or front-panel status without changing service settings.
  • Check only visible intake, exhaust, filter, clearance, condensate, and water-supply conditions that can be inspected without opening panels.
  • Take photos of the code, equipment nameplate, venting, surrounding equipment area, thermostat or controller, and any visible leak, ice, or obstruction.

When to stop and call GreenFlow

Call GreenFlow if the code repeats, the unit is locked out, hot water, heating, or cooling is not restored, or the concern involves gas, flame, combustion, venting, electrical components, refrigerant, pressure, water leaks, PCB/control boards, sensors, pumps, or warranty coverage.

Share the visible code, model and serial number if available, photos, current symptoms, and whether the issue affects heating, cooling, or both.

E615 questions

What does E615 mean on a Navien NCB-H Series?

The Navien manual for this product family lists E615 as: Abnormal operation: input and memory.

What should I safely check before scheduling service?

Record the displayed code, confirm thermostat or controller status, check only visible intake, exhaust, filter, clearance, and water-supply conditions, and take photos of the code and nameplate. Do not open gas, electrical, refrigerant, combustion, or internal equipment panels.

When should GreenFlow handle this code?

Call GreenFlow if the code repeats, the unit is locked out, hot water, heating, or cooling is not restored, or the concern involves gas, flame, combustion, venting, electrical components, refrigerant, pressure, water leaks, PCB/control boards, sensors, pumps, or warranty coverage.

Brands We Service

Popular cities

Service Areas

Our Happy Customers

Anna G.

They quickly identified the issue with the heating system and fixed it efficiently. He explained everything clearly and made sure I understood what was going on. Very professional and reliable, extremely satisfied with the service.

Michele Z.

Andrey was professional, prompt, smart, thorough and exceedingly pleasant. We are likely switching our current HVAC company to Green Flow.

Dev W.

I had a breakdown of my cooling system and Hanna at Green Flow responded to my request right away. They scheduled me same day. The team at Green Flow was easy to communicate with over phone and text. They kept me updated on delays on arrival of the...

Jack B.

Andrey always does a great job.

View All