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Navien Water Heater ⛔ Do Not Use

Navien Water Heater Error Code E045

Navien Water Heater error code E045: Water leak detected.

Last reviewed: Last updated:

Methodology: We combine OEM HVAC documentation with field repair patterns, then review for safety-first troubleshooting.

Sources: HVAC manufacturer documentation, installation/service manuals, and technician-reported repair patterns.

Limits: Guidance is informational and may not match every model-year or revision. Confirm with the official manual and diagnostics before replacing parts. For safety-critical or electrical work, use a qualified technician.

Is it safe?
⛔ No — stop using
Stop using immediately — water and electricity are dangerous. Unplug before inspecting.
Can I fix it?
Technician Recommended
Tools: Screwdriver set, Towels, Flashlight
Repair cost
DIY: $50–$200 (if hose/seal)
Pro: $150–$500
⏱ 30–120 min

What Does Error Code E045 Mean?

Navien Water Heater error code E045: Water leak detected.

Part that typically fails: Door seal / inlet hose / drain hose / pump

Stop using immediately — water and electricity are dangerous. Unplug before inspecting.

Symptoms You May Notice

Troubleshooting Steps

  1. 1 Check your owner's manual for model-specific guidance on error code reset procedures
  2. 2 If the error persists after reset and basic checks, contact a qualified technician
🛠️ Tools needed: Screwdriver set, Towels, Flashlight · Time: 30–120 min
⚡ Quick tip: Always try a full power reset first — turn the unit off at the breaker, wait 30 seconds, restore power.

Frequently Asked Questions

What does Navien Water Heater error code E045 mean? ▼
Error code E045 on a Navien tankless water heater indicates: Water leak detected. The unit has detected this condition and has limited or stopped operation to prevent further damage.
How do I fix Navien Water Heater error code E045? ▼
Start by powering the unit off for 30 seconds and restarting. If error E045 returns, the underlying cause (water leak detected) needs to be addressed. Check wiring connections and filters first before replacing components.
Is Navien error code E045 serious? ▼
It depends on the root cause. Some E045 errors resolve with a reset. Others indicate a failed component that requires professional repair. Don't continue operating with this error — it can lead to further damage.

More Navien Water Heater Error Codes

All Navien water heater codes → All Navien HVAC codes →

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