ET Series Immersion Heaters

Key Features

  • Keeps oil at approximately 80°F
  • Automatic built-in fixed setting thermostat normally closes at 70°F and opens at 100°F
  • Will not burn oil
  • UL recognized and CSA certified
  • Weatherproof wiring enclosure (NEMA 4)
  • 22 W/sq in power density on all ET Series heaters
  • Interior thermostat has a 250VAC maximum rating
  • For tanks larger than 500 gallon use multiple heaters
  • Heaters over 10 amps, 480 volt, or three phase must be used with a contactor
  • Amps = Watts ÷ Volts for single phase
  • Amps = Watts ÷ (Volts x 1.73) for three phase
  • Wiring diagram included with heater
  • Please refer to Immersion Heaters Install and Wiring Instructions for information on installation (Appendix RA-13 on page RA-A13

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Common Options Available

  • Ambiant Thermostat: open at 60° F/close at 40° F - 10A/240 VAC max (Part No. T-60)

Custom Options Available

  • Three Phase available on ET8 Models (add -3 to part number)
  • Explosion proof models available

Immersion Heaters are primarily used to help maintain oil temperature to avoid cold startups in cold operating conditions. They may also be utilized in water and other solutions.


  • Heaters must be mounted horizontally
  • Do not mount from the top down
  • Heaters must be immersed at all times
  • Heaters are not rated for DC current


  • The ET Series heaters will function when operated at lower than rated voltage, but with associated reductions in power output and effi ciency