Understanding Your RV Refrigerator

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There are many ways to keep your RV refrigerator up and working smoothly through an upcoming HOT summer. Even if you aren’t a ‘Do-It-Yourself’ person you can still save yourself a lot of hard-earned cash by doing preventative maintenance on the RV appliance to keep the serious issues at bay. There really is a lot of things to know and way too much to put into this post, however, we can cover a few critical points on just helping your unit run more efficiently.
  • Remember that for every minute the refrigerator door is left open it takes 1 hour for it to completely recover that cool temperature. If you have an ice chest or one of the new thermoelectric ice coolers that can plug into the 12-volt cigarette lighter, this will provide access to beverages and other items needed on a regular basis.
  • To keep the food inside your RV refrigerator safe you will need to maintain the temperature inside the lower compartment between 34 degrees F. to 43 degrees F.  Having a simple refrigerator thermometer hanging from one of the shelves will help you monitor that temperature. Know that once that degree hits 37 and lower, some items will start to freeze (veggies, fruits, eggs, and more) My favorite degree span is 38 to 41 F.
  • If placing a lot of foods, beverages, etc. into your refrigerator – chill it down before doing so. Using an ice chest with ice would be a good way to do that. However, if you are placing a 6 pack of drinks (etc) in your already cooled refrigerator, place one bottle or can between those that are already cooled. This will remedy the heat transfer more readily.
  • You can increase the cooldown time inside your refrigerator by 50% and then help maintain that cool temperature by having a battery operated circulating fan sitting on the bottom shelf of your unit. Since cool air settles to the bottom of your refrigerator, a circulating fan will pick up this cool air and throw it upward so it can be reused.
  • If you find that the temperature inside of your RV Refrigerator going up as the temperature outside of your RV goes up above 85 degrees F., you have what is known as a “refrigerator that is chasing the outside temperature”. This chasing is caused by poor airflow across the cooling coils that are mounted on the back of the refrigerator. Heat is not being pulled from these cooling coils so heat cannot be pulled out of the inside of the refrigerator.
  • These RV refrigerators are vented and cooled one of two ways

a.) Air enters the lower vent that is mounted on the side of the RV  and vented across the cooling coils and out of the roof vent or

b.) If the refrigerator is mounted in a slide-out you will have 2 sidewall vents. The cooling air is drawn into the lower vent then across the cooling coils and exhausted out the upper vent.

  •  Start by inspecting the rear refrigerator coils or upper vent for a bird’s nest, wasp nests or some other obstruction that could be restricting the cooling air flow.   If no obstructions are found, you will need to install a 12 volt or  solar-powered vent fan on the back of the refrigerator just above the coils. This vent fan draws in air through the lower vent and pushes it across the coils and out the roof vent or the upper sidewall vent taking the unwanted heat with it.

How an RV refrigerator works:

By Gary Bunzer aka the RV doctor  (He died of covid-19 in May 2020)

What is your freezer is getting cold but the refrigerator does not?  (After first start it takes several hours)

It might be your thermistor. 

The thermistor is a sensor that sits in the back of your fridge onto one of the fins. If it is dangling lose the fridge will probably not get cold. Put it back on a fin and move it up. The higher it sits the colder the fridge will get.

A thermistor can also go bad. This procedure should be followed to check the working;

Norcold thermistors are very important to the operation of your Norcold refrigerator. The word “thermistor” means a combination thermostat/ resistor. Simply put, this means that as the temperature increases or decreases, so does the resistance of the component. This makes troubleshooting the thermistor a fairly easy task as long as you have a multimeter capable of checking resistance (ohms).

Below is a table that explains the ohm resistance reading for various temperatures. Two easy temperatures to measure are 80 degrees (holding it in the palm of your hand for 30 seconds), or 32 degrees (placing it in ice water for 30 seconds).

If your thermistor is reading 0 ohms at any temperature, it is clearly bad. Usually, when these thermistors do fail, they will either read open or have an extremely low reading which would result in your refrigerator freezing everything.



Are you like me and decided to start my new month off by taking a good look at my RV Refrigerator/Freezer and making the decision it was time to defrost?  Well,  let’s get right to it…and spend a little time talking about how the defrosting process is done properly. Defrosting the RV refrigerator can be done with ease.

It doesn’t matter if you have a Norcold (like mine) or the Dometic brand. These steps will be the same.
Steps for defrosting the RV freezer:
  • Push the ON/OFF button to the OFF position. (You may have a switch that turns, regardless, turn to the off position)
  • Remove all foods.
  • Note: If you have a buildup of frost on the fins inside the refrigerator….this will defrost also and you will need to have a large bowl ready outside at the back of your unit to catch the water as it drains out. (you will need to remove the access panel)
  • The Norcold drain tube (photo) rests inside a small drain pan but the water will need to go in a large bowl because the drain pan is too small to hold a significant amount of water.
  •  Dometic has a drain tube (photo) but not a drain pan. The water will go through the tube and out the grill on the back side of the refrigerator.  Make sure that the tube is resting through the grill at all times to avoid water seeping down behind the appliance and causing damage.
  • Place dry towels inside (on the floor) of the empty freezer for soaking up melted frost.
  •  Placing bowls of warm tap water (not boiling) in the bottom of the freezer (photo on the right) will speed up the defrosting process. Caution: never use high temperature water – warping/melting can occur of the inside walls. Never use a hair blow dryer, any source of fire or sharp tools during defrosting.
  • Once all frost has melted use dry towels to remove all water. Clean inside with warm moist towel with a mild soap. Avoid harsh cleansers of any kind.
  •  Replace all foods and restart your RV refrigerator.
  •  Don’t forget to place the drain tube back into the drain pan on the backside of the unit. (Norcold brand)

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