RV Pro Article August 2007

Procedure 4: If no rapid boil is noted, level the refrigerator and allow the unit to run for approximately one hour. After such time some warming should be noted in the bottom absorber coil, some cooling observed in freezer compartment, and considerable warming present at the top of steam line, just before the condenser. If these conditions are present, place a thermometer in the refrigerator compartment and allow the unit to run overnight. Check the refrigerator temperature the next day. Regardless of ambient temperature, the thermometer in refrigerator should read below 32 degrees.
    When troubleshooting while running on 110V, the use of a temperature probe in the refrigerator compartment is recommended. This will give an accurate temperature while eliminating the need to open the door to the refrigerator. The ideal temperature is 35 degrees. If using a standard refrigerator thermometer, place it in a bowl of water before beginning the testing. That way when you remove it from the refrigerator to read it, you won't lose degrees too quickly, allowing time to get an accurate reading (see images 2-3).
    The next day, if the refrigerator temperature reads below 32 degrees, it proves that the cooling unit is working properly. There is a control causing the insufficient cooling and it needs to be repaired or replaced. If the refrigerator temperature is above 32 degrees, the cooling unit is causing the insufficient cooling and it needs to be reconditioned.
    Normal refrigeration is considered 38 to 40 degrees in the refrigerator compartment, while 0 degrees is the target in the freezer compartment (all temperatures are nominal). When hooking direct to the 1l0VAC heating element, you are running the unit "wide open" with no controls. This is why lower temperatures are acceptable.

Roger and Onna Lee Ford are the owners of Ford RV Refrigeration, a Benton, Ky., business that specializes in the field of RV refrigerator reconditioning. The business sells a step-by-step instructional manual and customized tools needed to reconditioning RV refrigerator cooling units, offers certified technician training, and issues membership for the RV Refrigeration Network (RVRN, an association of businesses that provide RV refrigerator reconditioning services. For more information, visit the company website at www.rvrefrigeration.com. To contact the Fords, call 270-354-9239 or e-mail them at fordrv@rvrefrigeration.com.

Absorption refrigeration systems used in RVs are small and quiet with few moving parts, making them the perfect refrigerator for the road. However, these units do periodically fail, leading customers to complain of insufficient cooling.

Due to a lack of education, when a problem occurs service techs often condemn the cooling unit or even the entire refrigerator. However, with the right training, technicians can properly diagnose the real problem, potentially saving the customer money and aggravation and in the process creating goodwill and possibly extra business for your dealership or shop.

The first step with troubleshooting is to determine whether there is a control or cooling unit problem. When diagnosing, follow these easy procedures:

Procedure 1: Inspect the cooling unit for any yellow coloring. Yellowing is caused by sodium chromate, a rust inhibitor, and is usually found in the boiler pack area (although yellowing can occur elsewhere). Yellowing indicates a leak in that area.

Procedure 3: Probe inspection. Of note, do not troubleshoot the cooling unit using 12-volt connection or LP gas. 110VAC ensures accurate results.
Bypass all controls by connecting 110VAC directly to heat element. This allows testing of the cooling unit without interference from other controls.
Ensure the heat element is the required wattage for a unit being serviced by probing heat element with an amp probe (see image 1). Remember, Volts X Amps = Watts. Example: 110VAC X 2.25A = 247.5 W (A 10 percent cushion either way is allowable.)

However, it is important to note that in the heat of summer, when ambient temperature is 90 degrees or higher, the refrigerator temperature may only read in the high 20's. In cooler seasons, when temperature drops significantly, that same refrigerator's temperature may read in the single digits. Ambient temperature plays a big part in these types of cooling units.

If it has been determined the cooling unit has a leak, proceed to Step 2.

Step 2: Removing the Refrigerator from the RV

Removing a refrigerator from an RV is not a difficult task; however, it does take knowledge and in some cases, it requires two people.
To remove the refrigerator from the RV, the following items are required: a drop cloth, needle-nose pliers, two crescent wrenches (8 or 10 inches), a Phillips screwdriver and possibly a square head screwdriver, a 3/8-inch Bare plug for the gas line supply, and a cap for the propane supply side. Also, for all of the following procedures, if at any time, force of any kind is required safety glasses should be worn.
General procedures for removing a refrigerator from an RV are as follows:

Shut off the propane at the main tank valve.
Mark the position of the 12VDC wires. Disconnect the 12VDC wires and the tape positive wire.
Using two crescent wrenches, one on the refrigerator connection and the other on brass Bare nut, disconnect the LP gas line. Do not loosen this nut without a back-up wrench as indicated.
Plug the gas line on the camper and check for leaks so that you can use the gas for other appliances in the RV, if needed. Put a cap on the pro pane supply side on the refrigerator.
Outside the vehicle, remove screws or bolts in the lower rear section of
unit (if any are present).

Inside the vehicle, cover the Boor and any other areas that removal could damage with a drop cloth. Remove the refrigerator doors. This is not a necessity, but it helps in making the load lighter.
Remove the four (or six) screws around the frame, which hold the refrigerator to the wall. Sometimes they are only on the sides, other times they are on the top and/or bottom. Slide the refrigerator out of opening and remove to the service area.

Cooling Unit Removal

At this time, you can either leave the refrigerators doors off, or reinstall them to the cabinet. To remove the cooling unit from the refrigerator cabinet you will need: a Philips screw driver, a pry bar and an 1- X 4- X 6-inch piece of wood.

Tools in hand, proceed accordingly:
- Remove the screws holding the evaporator fins inside the refrigerator compartment (see image 4).
- Remove the screws or bolts in the freezer compartment (see image 5).
- On the units with bolts, you will need to remove the shelf that the bolts were in. Do so by pulling it straight out (see image 6).
- Extract the thermostat capillary tube from inside the cabinet, if necessary (see image 7).You now remove any control wiring on the back of the refrigerator in order to be able to remove the cooling unit. To ensure accurate reassembly, mark positions of any wiring and controls before beginning disassembly.Next, place a protective barrier on the Boor so that when you lay the refrigerator on its front, you protect the outer cabinet/ doors. Cardboard, carpet, or any thing of that nature will work.
- Lay the refrigerator on its front â€¢ on top of the protective barrier. You should now be looking

at the cooling unit, which is on the backside of the refrigerator.

Remove the boiler pack, which is located on the lower right side. There are four tabs on the boiler pack. Unhook the tabs from their slots. Do not straighten them out, as they may break off. The easiest and safest way is to squeeze the cover, which allows the tabs to come out. Remove this cover by rolling it counter clockwise off the boiler, and then it will lift right off.
Remove the electric heating element.

To remove the heat element, use a gentle twisting motion as you pull the heat element out of its sleeve. If any excessive force is required, safety glasses should be worn.

Remove the screw holding the sheet metal cover around the burner assembly. Remove the cover.
Remove the screws holding the burner assembly in place and carefully set the burner aside (see image 8).
Remove the screws holding the cooling unit to the cabinet.
At this point it bears mentioning, the following procedure could be hazardous to your eyes. Safety glasses should be worn at all time, and

have eye-flushing solution nearby.

A note of caution: Pry only under the large tube exiting the evaporator. Such force exerted elsewhere could damage the cooling unit.
Lift upward on the cooling unit tubing that passes through the urethane to and from the evaporator.
A helpful hint: Create a downward pressure with your toes on the 1,4 inch lip of the refrigerator frame.

If a pry bar is necessary, place it on the 1 X 4 X 6 inch piece of wood

to protect box. Different sizes of wood may be necessary for different makes and models of refrigerators. The cooling unit is now exposed and ready for reconditioning.

In our 24 years of RV refrigerator reconditioning, we have never had any accidents of any kind because safety is our No. 1 priority. When you become educated and do the do's and don't the don'ts, accidents do not happen.