A.O. Smith E6-50H45DV Water Heater Problems & Error Codes — Overview
The A.O. Smith E6-50H45DV is a 50-gallon electric water heater in the manufacturer’s residential tank line. These units typically run on 240 VAC and use a dual-element heating system rated at 4500 watts. Like most electric tank heaters, the upper element and thermostat handle the heavy lifting when recovery demand is high, so they fail more often than lower components. A.O. Smith’s own troubleshooting guidance points to loss of power and burned-out upper elements as the two most common reasons for no hot water.
Error codes on electronic control versions require the specific fault legend from the service manual for this model, which is not widely published online. If your unit displays a code, write down the exact alphanumeric string and check the label inside the access panel or contact A.O. Smith support directly. For most field repairs, you will be testing voltage at the upper thermostat, inspecting element continuity, and replacing the upper thermostat or high-limit assembly when components test open or out of spec.
Most Common Problems on This Model
- No hot water at all Most often caused by no incoming power at the breaker or a burned-out upper heating element that interrupts the entire heating circuit.
- Not enough hot water or slow recovery Lower heating element has failed or the lower thermostat is set too low or stuck, so only the upper element is working.
- Tripping breaker repeatedly Heating element has shorted to the tank wall or wiring connections are loose and arcing, drawing excess current.
- High-limit switch trips and unit shuts off Upper thermostat has failed closed and overheats the tank, or the high-limit button itself is faulty and needs replacement.
- Water is too hot even on lower settings Upper thermostat is stuck closed or calibrated incorrectly and continues to send power to the element past setpoint.
- Error code displayed on control panel Fault meaning is specific to the code and requires the service manual legend for this model to identify the failed sensor, switch, or control.
- Leaking from element gasket or flange Element gasket has deteriorated or the flange bolts were overtorqued during past service, cracking the porcelain lining.
- No power to upper thermostat Supply voltage does not match the data plate rating (usually 240 VAC), or home wiring has an open leg or bad connection at the heater junction box.
Parts That Commonly Fail
| Part | Notes |
|---|---|
| Upper heating element | Amazon | Fails open or shorts to ground, killing all hot water or tripping the breaker. |
| Upper thermostat and high-limit assembly | Amazon | Thermostat contacts weld shut or high-limit button trips repeatedly when the sensor or switch goes bad. |
| Lower heating element | Amazon | Burns out less often than the upper but will cut recovery capacity in half when it fails. |
| Lower thermostat | Amazon | Sticks or loses calibration, leaving you with lukewarm water even when the element is good. |
Water-Heater Error Codes for This Model
These codes apply to this model line:
- A O Smith Water Heater E2 error code
- A O Smith Water Heater E4 error code
- A O Smith Water Heater E6 error code
When to Call a Pro
Call a licensed electrician if you measure zero voltage at the upper thermostat, find mismatched supply voltage compared to the data plate, or see signs of arcing or burned wiring inside the junction box. If an error code appears on the control panel and you do not have the service manual legend for this exact model, contact A.O. Smith support or a factory-trained technician to decode the fault and identify the failed component. Any time you are uncomfortable working with 240-volt circuits or need to drain and remove elements, a plumber or appliance tech can complete the repair safely and verify proper reassembly and gasket seal. For gas line, burner, or igniter work, or if you ever smell gas, stop and call a licensed technician.