What the code means
E432: Cold water inlet 2 thermistor open or short
The Navien manual for this product family lists E432 as: Cold water inlet 2 thermistor open or short.
Troubleshooting code
Back to all NPE-S2 Series error codes
Navien NPE-S2 Series E432 troubleshooting
Cold water inlet 2 thermistor open or short. Use this page to document the issue and prepare for service. GreenFlow should handle diagnosis for electrical, refrigerant, lockout, or recurring conditions.
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.
E432 questions
What does E432 mean on a Navien NPE-S2 Series?
The Navien manual for this product family lists E432 as: Cold water inlet 2 thermistor open or short.
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.
Need help with this code?
GreenFlow can review the code, photos, equipment access, and symptoms before scheduling the right next step.
Brands We Service
No matching featured brand found.
Popular cities
Service Areas
No matching service area found
Try another nearby city or contact GreenFlow to confirm service availability.
Our Happy Customers
John F.
I needed 2 new AC units and decided to go with high efficiency heat pumps. I chose Greenflow because of the equipment they offered, and the price (2nd lowest quote and much cheaper than the average of all quote we received). Their technicians were very detail oriented and...
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.
Sharad W.
Green Flow and the people who work there are terrific. Vlad and Andre are excellent. Andre was very helpful. He was punctual, respectful, efficient and knowledgeable. He did not try to sell me something I didn’t need ( as others have done before). I was charged $99 which...
Melissa S.
The repair person came quickly and was super efficient and polite, and showed me what to do next time. He gave my dog a quick pay and was off again.