State water heater thermopile
Use after confirming low millivolt output and matching the pilot assembly style.
State water-heater error-code guide for gas, electric, and heat-pump models, including LED flashes, display faults, sensors, and elements.
State water-heater error-code guide for gas, electric, and heat-pump models, including LED flashes, display faults, sensors, and elements.
Parts to price first
Use after confirming low millivolt output and matching the pilot assembly style.
Match voltage, wattage, and screw-in style before replacing E1/E2 element faults.
Match upper or lower position and electrical rating before replacing thermostat faults.
Match tank height and thread style when replacing an anode for sulfur odor.
State Water Heaters are manufactured by A.O. Smith and use nearly identical control systems. State models include ProLine, ProLine XE, Select, Vertex, and Premier series. Error codes depend on the model type.
State gas water heaters with piezo ignition and thermocouple control use an LED status indicator on the gas valve:
| Flash Code | Meaning | Action |
|---|---|---|
| 1 flash (slow) | Normal, pilot lit | None |
| 2 flashes | Thermopile voltage low | Clean thermocouple, relight pilot |
| 3 flashes | Pressure switch (power vent) | Check vent, inducer |
| 4 flashes | Exceeded temperature limit | Lower setpoint, check safety |
| 5 flashes | Sensor fault / wrong reading | Replace temperature sensor |
| 6 flashes | Gas valve solenoid fault | Replace gas control valve |
| 7 flashes | Pilot failed to light | Relight pilot, check thermocouple |
| Rapid flashing | Control board fault | Replace gas control valve |
State gas valves are commonly made by Honeywell or White-Rodgers and use similar flash codes to Rheem and Bradford White.
State ProLine XE and Select electric water heaters with digital controls:
| Code | Meaning | Fix |
|---|---|---|
| E1 | Upper element or sensor fault | Test element (see below) |
| E2 | Lower element or sensor fault | Test lower element |
| E3 | Thermostat or sensor fault | Replace thermostat |
| E4 | Control board error | Replace board |
| E5 | High limit tripped | Reset, investigate |
| EE | EEPROM memory fault | Power cycle, then replace board |
Most State electric water heaters use two heating elements (upper and lower). To test:
Common State element spec: 4500W / 240V = ~12.8 ohms
The high-limit thermostat (ECO, Energy Cut Off) is behind the upper access panel, under the insulation. It’s a red-button reset device. After resolving the cause, such as thermostat failure or a failed element creating runaway heat, press the red button firmly until you hear a click.
State ProLine XE Heat Pump (GPHE series) shares controls with A.O. Smith Voltex:
| Code | Meaning |
|---|---|
| E1 | Temperature sensor fault |
| E2 | Refrigerant system fault |
| E3 | Fan motor fault |
| E4 | Control board fault |
| E5 | Compressor fault |
In ELECTRIC mode, all E-codes disappear and the unit runs on resistance only. If your unit shows E2-E5 only in HEAT PUMP mode, the refrigerant circuit is at fault and requires a certified HVAC technician.
State power vent water heaters (SPDH, GPVD series) add a combustion blower to pull exhaust out. Code 3 flashes means the pressure switch on this blower didn’t close.
Check:
State water heaters come with a magnesium anode rod. If your water smells like sulfur, the anode is reacting with certain bacteria in the water. An aluminum/zinc anode rod eliminates the odor in many cases. Inspect the anode every 3-5 years.
| Situation | Recommendation |
|---|---|
| Heater under 8 years, clear error code | Repair (replace component) |
| Heater 8-12 years, E4 (board fault) | Consider replacement because parts cost approaches heater value |
| Heater over 12 years, any fault | Replace entire unit |
| Heater leaking from tank body | Replace immediately because tanks do not repair |
Before ordering, match the water-heating part to the model number, electrical rating, and failure symptom:
State water heaters are made by A.O. Smith, so many State models share control systems, LED patterns, and repair logic with comparable A.O. Smith water heaters.
Three flashes usually means the pressure switch did not close. Check whether the blower runs, vent pipes are clear, the pressure-switch hose is connected, and the switch closes.
Turn off the breaker, disconnect the element wires, and measure resistance across the terminals. Most 4500W 240V elements read about 12.8 ohms, while open or shorted elements should be replaced.