RV Repair Manual
for the RV Do-It-Yourselfer
RV absorption refrigerators operate much differently than household compressor-driven models. Instead of a mechanical motor, they rely on heat (from a 120V AC element, 12V DC element, or LP gas burner) to circulate ammonia refrigerant. Turn your RV refrigerator on at least 12 to 24 hours prior to loading food so the cooling unit stabilizes. Loading pre-chilled food just before departure helps maintain cold temperatures.
Always keep a dedicated RV refrigerator thermometer inside the food compartment to monitor cooling. Perishable food degrades rapidly at temperatures above 40°F (4°C). Adding an internal 12V RV fridge circulation fan significantly improves air movement across the cooling fins, keeping temperatures uniform top-to-bottom.
Many Dometic absorption refrigerators feature a "High Humidity" or "Climate Control" switch on the eyebrows or door frame. This switch powers a small low-wattage heating element inside the freezer door frame to prevent condensation sweat from dripping down the front of the cabinet during humid weather.
While the heater draws a small current (around 0.5 to 0.6 amps at 12V DC), it operates continuously – even when the main refrigerator power switch is turned off on many models. Left turned on while dry camping or in storage, this continuous draw consumes 12 to 14 amp-hours daily and will discharge a standard 12V house battery over a weekend.
Troubleshooting Tip: If your RV house battery drains unexpectedly during dry camping or storage, verify that the Dometic High-Humidity switch is turned off. Tracking parasitic drains with a digital RV battery monitor shunt quickly pinpoints hidden 12V draws.