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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 877 378-3744 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.
Editor's note: This guest column is the first in a three-part series that looks at reconditioning RV refrigeration systems from a technical perspective. This first article examines troubleshooting techniques that can help technicians determine what the problem is. The two subsequent articles will address reconditioning RV refrigerator systems.
It's an unfortunate fact that absorption refrigeration systems in RVs periodically fail. Effective troubleshooting is key to getting problems fixed.
(EDUCATION)

If, within two minutes, a rapid boiling - often referred to as a gurgling noise - is noted coming from boiler section, the unit contains a leak. This cooling unit needs to be reconditioned.
Procedure 2: Open the refrigerator door and check for ammonia odor. If an odor is present, this indicates a leak in lower evaporator section. If the refrigerator is a two-door model, open the freezer compartment and check for ammonia odor there as well. If detected, this indicates a leak in the upper section of the evaporator coil.
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.)
Image 2: Temperature Probe
50 RV PRO AUGUST 2007
Image 1: Bypassing Controls
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.
Image 3: Standard Refrigerator Thermometer
Image 4: Evaporator Fins
Image 7: Thermostat Capillary
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:
Image 6: Refrigerator Shelf
Image 8: Burner Assembly
AUGUST 2007 RV Pro 51
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:
at the cooling unit, which is on the backside of the refrigerator.
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.
have eye-flushing solution nearby.
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.
AUGUST 2007 RV PRO 53
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