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Westinghouse Part

Westinghouse Thermostat — Upper and Lower

Upper thermostat (with ECO) and lower thermostat for electric storage tanks. Universal surface-contact thermostats interchange.

Updated May 2026 · Westinghouse Water Heaters

Westinghouse electric storage tanks (WER series) use industry-standard surface-contact thermostats. Same architecture as Rheem, AO Smith, Bradford White, and Marathon. Universal aftermarket thermostats fit Westinghouse.

Upper thermostat (with ECO)

  • Includes Emergency Cutoff (ECO) red reset button — trips at ~180°F
  • Controls upper element AND transfers power to lower thermostat
  • Setpoint range: 90-150°F (factory 120°F)
  • Spring-clip mounting to tank shell contact plate

Lower thermostat

  • Controls lower element only
  • No ECO function
  • Setpoint 90-150°F (factory 120°F)
  • Same spring-clip mounting

Diagnosis

Multimeter continuity test:

  • Disconnect leads at thermostat
  • Check continuity across terminals when tank below setpoint
  • Should show continuity (closed)
  • Open when expected closed = stuck open; replace
  • Continuity always present = stuck closed; replace (will trip ECO)

Replacement

  1. Power OFF at 240V breaker; verify with voltage tester
  2. Remove access cover
  3. Fold back insulation; remove safety cover
  4. Photograph wiring
  5. Disconnect leads
  6. Release spring clip; lift thermostat off (no draining required)
  7. Clean contact plate surface
  8. Press new thermostat firmly against plate — clean contact essential
  9. Reconnect leads per photo
  10. Verify dial position (factory 120°F)
  11. Replace cover; restore power

Cost

  • OEM Westinghouse upper thermostat (with ECO): $20-35
  • Universal Honeywell L4006A or Camco upper: $10-20
  • Lower thermostat: $10-20
  • Within 6-year parts warranty: Westinghouse covers thermostat
  • Plumber labor if hired: $60-120

Bottom line

Universal thermostats fit Westinghouse. Always clean contact plate before installing. Upper is primary (controls all power); lower is dual-element only.