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High Pressure Switch Activates in the HEAT Mode

During the operation of your marine air conditioner in the HEAT mode, the RESET (high pressure) switch activates.

When the high pressure switch activates in the HEAT mode the evaporator is not being properly relieved of heat. This is usually due to air flow restrictions. Remove the restriction.

  • Dirty air filter
  • Blocked return air
  • Return air grill smaller than specified physical size
  • Closed or insufficient number of supply air grilles
  • Duct runs too long, too many turns or kinked creating a heat back up on theevaporator

NOTE: Another commonality of this behavior is the operation of the HEAT mode when not called for.  "Testing" your HEAT mode for any short degree of time during warm temperatures will result in high pressures on your system thus resulting in the RESET button activating.