Keeping Your RV Refrigerator Cool... the Basics for Motorhomes, Fifth Wheels and Travel Trailers
Some refrigerators installed in motorhomes also have a 12 volt DC heating element. These are often referred to as three-way refrigerators... propane, 120 vAC and 12 vDC. The 12vDC heating element draws several amps and can discharge a battery in a short time. Therefore three-way refrigerators are usually found in motorhomes and are intended to allow the unit to be operated while traveling. Remember, when the engine is not running the battery is not being charged by the alternator. Also, make sure the alternator in your vehicle is large enough to power all the lights, charge the batteries and operate the refrigerator.
It is important to keep an RV refrigerator level during operation to avoid irreparable damage. This is especially important in older units... pre 1986 or so. For newer refrigerators it's only necessary to keep it reasonably level... if your motor home, travel trailer or fifth wheel is comfortable then the refrigerator is likely level enough. Before you use your refrigerator for the first time place a small bubble level on a refrigerator shelf. Adjust the the level of your RV until the refrigerator is level. Then find a countertop or some other place on the RV that also reads level. This will be your reference from now on. If you keep the level in the frig and you open the door several times to check for level the refrigerator can take an hour or more to recover.
Here's some tips for getting the most from your RV refrigerator.
Pre-cool the refrigerator for several hours before use.
Put only cold things in the refrigerator... buy cold sodas and beer or pre-cool them in your home refrigerator.
Keep the refrigerator well stocked with items that hold the cold well. Things like cans of soda, beer and bottles of water etc. will give up some of their cold to the air in the refrigerator and help keep other things cold until the refrigerator can recover.
Plan ahead. Know what you will need from the refrigerator before you open the door. Get everything at the same time and put it all back at the same time.
You may also want to read: Is it okay to travel with my RV Refrigerator on propane?