Whirlpool electric tanks have two thermostats. Upper integrates the ECO red reset button. Both control their respective elements.
Symptoms
- No hot water (upper stuck open or ECO tripped)
- Boiling/scalding water (stuck closed)
- Lukewarm only (lower stuck open)
- Element burned out shortly after replacement (thermostat over-fired)
Test with multimeter
- Turn off breaker
- Disconnect wires (note positions)
- Continuity across terminals — should change with temperature
- Permanently open or closed = failed
Replacement
- Turn off breaker
- Remove access panel
- Note wire positions; disconnect
- Slide thermostat out (spring clip on some)
- Insert new thermostat
- Connect wires per notes
- Set to 120°F
- Replace panel; restore breaker
Critical: same temperature both
Upper and lower must be set to same temperature. Mismatched = unpredictable performance and short element life.
ECO reset on upper
Press red button firmly. If clicks and works briefly then trips again, underlying cause still active.
Cost
- Upper thermostat with ECO: $30-50
- Lower thermostat: $25-40
- Pro: $150-250
Bottom line
Test before replacing. Match wires when reconnecting. Both thermostats same temperature. $30 + 30 min.