MARS 39004 Switch The inclusion of a 12A09

The inclusion of a 12A09 vlimiter (vent limiter) eliminates the need for vent piping to the outdoors in most indoor installations

restricted airflow

When troubleshooting pressure switch lockout or incomplete combustion issues

OEM Compatibility: Authentic Amana-Goodman replacement part ensures exact fitment and restores original equipment performance

providing reliable data for critical environmental adjustments

MARS 39004 Switch The inclusion of a 12A09The MARS 39004 is a professional grade 390 Series SPDT Changeover Switch designed for automatic seasonal transition in hydronic heating and cooling systems. Specifically engineered for fan coil units, this summer winter changeover switch manages thermostat logic based on water temperature, ensuring seamless climate control without manual intervention. It features a high reliability SL 8 thermostat enclosed in a sealed case for environment protection