Coleman Mach 7330A3231 Air Conditioner Freeze Control Switch
An OEM-spec freeze control sensor switch engineered to protect your Coleman Mach RV air conditioner evaporator coil from ice buildup -- keeping your system running efficiently and preventing costly compressor damage.
When an RV air conditioner runs in high-humidity conditions or with restricted airflow, the evaporator coil can drop below freezing and ice over. Left unchecked, this strains the compressor and can lead to premature failure. The Coleman Mach 7330A3231 Freeze Control Switch monitors coil temperature and cuts power to the compressor before icing becomes a problem -- then automatically resets once safe operating temperature is restored.
This is a genuine OEM Coleman Mach replacement part, engineered to the same specifications as the original component installed at the factory. It is designed for specific Coleman Mach ceiling assembly air conditioner units and restores correct freeze-protection functionality when the original switch fails, sticks, or gives erratic compressor cycling.
Direct factory-spec replacement. No modifications needed for compatible ceiling assembly units.
Monitors coil temperature and disables the compressor before ice can form and cause damage.
Resumes normal compressor operation automatically once the coil returns to a safe temperature.
A failed freeze switch is a common cause of compressor short-cycling -- replacing it often restores normal operation.
The freeze control switch uses a capillary tube or bimetal sensing element clipped directly to the evaporator coil fins. When coil temperature falls to the switch's lower trip point (typically around 32 deg F), it opens the circuit to the compressor contactor, shutting down compression while the blower fan continues to run. Once the coil warms back above the reset threshold (typically 45-55 deg F), the switch closes and the compressor restarts. This cycle protects the coil, the refrigerant metering device, and the compressor itself.
The switch mounts inside the ceiling assembly (air handler section) of the Coleman Mach unit. Access requires removing the interior ceiling assembly cover. The sensing capillary is secured to the evaporator coil fins, and the two switch leads connect to the existing wiring harness using the original connectors. No soldering is required on compatible units.
This switch is designed for specific Coleman Mach ceiling assembly models. Not all Coleman Mach units use the same freeze control switch. Confirm your unit's model number (found on the data plate on the rooftop condenser shroud) matches the 7330A3231 application before purchasing. Using an incorrect switch can result in improper trip temperatures and compressor damage.
Before condemning the freeze switch, check that the return-air filter is clean and that the ceiling assembly vents are not blocked. A clogged filter restricts airflow across the evaporator and will cause repeat icing regardless of the switch condition. Clean or replace the filter, then test the switch with a multimeter -- it should read continuity (closed) at room temperature.
Clean the evaporator coil and return-air filter at the start of each cooling season. Restricted airflow is the leading cause of premature freeze switch trips and evaporator coil icing in RV air conditioners.