🚿Water Heater

E05

A.O. Smith · HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater

A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater E05 Error Fix: Evaporator Coil Sensor Failure

The evaporator coil temperature sensor has failed — open or short circuit. The heat pump cannot properly control the refrigeration cycle without monitoring evaporator temperature. The unit will likely disable heat pump mode and operate on electric backup elements only. Disconnect power and inspect the evaporator sensor and its wiring. Replace the sensor if readings are out of specification.

Medium severity2 fixes available✨ Free fix available

Quick Answer

Error E05 on the A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater means: Evaporator Coil Sensor Failure. The top-ranked community fix is “Test and Replace Evaporator Coil Temperature Sensor” (medium difficulty, ~45 min, DIY cost: $10-$20). 2 community-ranked fixes available below.

Published February 2026 · 2 fixes · water heater

Content is based on manufacturer service documentation, community repair experience, and OEM technical bulletins. Always verify with your owner's manual.Learn about our editorial standards.

When to Call a Professional

While many water heater repairs can be done safely at home, consider hiring a qualified technician if:

The repair involves electrical wiring, gas lines, or refrigerant
You've tried the top-ranked fix and the error persists
You smell gas, see sparking, or notice water leaking
The repair requires specialized tools you don't have
Your appliance is still under manufacturer warranty

Average professional repair cost for this issue: $120-$220.

Other A.O. Smith Models with Error E05

AHPTU-80 Voltex Hybrid 80 Gal 4500W Hybrid Heat Pump Water Heater with WiFi Connectivity

water_heater · 2 fixes

Other A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater Error Codes

E01

Upper Tank Sensor Failure

2 fixes

E02

Lower Tank Sensor Failure

Dry Fire / ECO Trip

Compressor Discharge Over-Temperature

2 fixes

E06

Condenser Fan Motor Failure

Compressor Failure

High Pressure Switch Activated

2 fixes

E09

Low Ambient Temperature

2 fixes

People Also Ask About A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater Error E05

What does error code E05 mean on a A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater?

Error code E05 on the A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater means: Evaporator Coil Sensor Failure. The evaporator coil temperature sensor has failed — open or short circuit. The heat pump cannot properly control the refrigeration cycle without monitoring evaporator temperature. The unit will likely disable heat pump mode and operate on electric backup elements only. Disconnect power and inspect the evaporator sensor and its wiring. Replace the sensor if readings are out of specification.

How do I fix error code E05 on my A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater?

The most successful fix is "Test and Replace Evaporator Coil Temperature Sensor" (medium difficulty, ~45 minutes). Estimated DIY cost: $10-$20. HomeMD has 2 community-ranked fixes for this error.

Is error code E05 on a A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater serious?

This error is rated medium severity. It should be addressed soon, but your appliance may still function in a limited capacity.

Can I fix A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater error E05 myself?

Yes — the top-ranked community fix ("Test and Replace Evaporator Coil Temperature Sensor") is rated medium difficulty and takes about 45 minutes. Tools needed: Multimeter, T20 Torx screwdriver, Needle-nose pliers.

How much does it cost to repair A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater error E05?

DIY cost: $10-$20. Professional repair typically costs $120-$220. Many homeowners save money by trying the top-ranked community fix first.

What other error codes does the A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater have?

The A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater has 8 other known error codes, including: E01 (Upper Tank Sensor Failure), E02 (Lower Tank Sensor Failure), E03 (Dry Fire / ECO Trip), E04 (Compressor Discharge Over-Temperature), E06 (Condenser Fan Motor Failure), and 3 more.

Which other A.O. Smith models have the E05 error?

Error code E05 also appears on 1 other A.O. Smith model: AHPTU-80 Voltex Hybrid 80 Gal 4500W Hybrid Heat Pump Water Heater with WiFi Connectivity. The fix may vary by model, so check each model's specific page for tailored repair steps.

What other error codes does the A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater have?

The A.O. Smith HPTU-50N HE Hybrid 50 Gal 4500W High Efficiency Hybrid Heat Pump Water Heater has 8 other known error codes:

E01 — Upper Tank Sensor Failure (2 fixes)
E02 — Lower Tank Sensor Failure (2 fixes)
E03 — Dry Fire / ECO Trip (2 fixes)
E04 — Compressor Discharge Over-Temperature (2 fixes)
E06 — Condenser Fan Motor Failure (2 fixes)
E07 — Compressor Failure (2 fixes)
E08 — High Pressure Switch Activated (2 fixes)
E09 — Low Ambient Temperature (2 fixes)

Which other A.O. Smith models have the E05 error?

Error code E05 also appears on 1 other A.O. Smith model:

AHPTU-80 Voltex Hybrid 80 Gal 4500W Hybrid Heat Pump Water Heater with WiFi Connectivity (water heater) · 2 fixes

Ad Space — banner

Replace ADSENSE_PUBLISHER_ID in AdUnit.tsx