A.O. Smith Error Code UPR: Upper Element Fault

Severity
Warning
Type
digital display
Estimated repair cost: $100 — $350 (parts + labor)
Warning: Your A.O. Smith water heater has detected a fault with the upper heating element and has shut down to prevent damage. You will not have hot water until this is resolved.

How to Fix A.O. Smith Code UPR

  1. Step 1: Check the house circuit breaker for the water heater. Reset it if it has tripped.
  2. Step 2: If the breaker trips again immediately, leave it off and call a qualified technician.
  3. Step 3: If the breaker stays on, wait 30 minutes and check if the water heater is producing hot water. If not, call a qualified technician.

How to Reset A.O. Smith Code UPR

  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.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does A.O. Smith Error Code UPR Mean?

The 'UPR' error code on your A.O. Smith water heater indicates a problem with the upper heating element. This element is responsible for heating the top portion of the tank, providing you with hot water. The control board has detected either a short circuit, an open circuit, or some other electrical anomaly with this element. Because of this fault, the water heater has likely shut down the heating process to prevent further damage to the element or other components. This means you'll be without hot water until the issue is addressed. It's important to resolve this promptly to avoid potential issues like sediment buildup in the tank due to inconsistent heating.

Common Causes

  • Failed Upper Heating Element: The heating element itself has burned out or shorted out.
  • Loose Wiring: The wiring connections to the upper heating element are loose or corroded.
  • Faulty Thermostat: The upper thermostat is malfunctioning and not properly regulating the element.
  • Sediment Buildup: Excessive sediment around the element is causing it to overheat and fail.
  • Control Board Malfunction: The control board is incorrectly detecting a fault even though the element is fine.

Diagnostic Steps

If... Check Expected
Water heater is powered off Voltage at the upper element terminals 240 VAC when heating
No voltage present Continuity of the upper heating element Around 10-15 ohms (check element rating)
Element shows open circuit Resistance between element terminals and tank Infinite resistance (no continuity)
Element shows continuity to tank Thermostat operation Thermostat closes circuit at proper temperature

Applicable A.O. Smith Models

Replacement Parts

Part OEM Number Est. Cost Where to Buy
Upper Heating Element — — —
Upper Thermostat — — —
ECO (Energy Cutoff) Switch — — —

Related Codes on Same Models

Other codes that affect the same A.O. Smith model families as UPR.

Code Description Severity
E06 Flammable Vapor Detection Critical
E1 Thermistor Failure Warning
E2 Dry Fire Protection Warning
E3 Sensor Fault Warning
E4 High Temperature Cutoff Critical
E5 Communication Error Warning
ECO Emergency Cutoff Critical
LOC Controls Locked Warning
LWR Lower Element Fault Warning