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The cooling unit is the set of metal coils that are attached to the back of your refrigerator.
The boiler section is overheating.

The boiler section is the part of the RV refrigerator where heat, by either electric or propane, starts the refrigeration process. When a cooling unit is operated level, has the correct heat input, and has good ventilation, the unit runs at a safe temperature (with just a few exceptions) and can expect a long happy life. But when one of these components is missing, bad things happen to the cooling unit. 

When the cooling unit reaches a critical temperature, the refrigerant in the system starts breaking down. This may be noticeable in small increments by a fridge that doesn't get as cold as it used to and progressively gets worse, or the unit all of a sudden ruptures in the boiler tubing, causing a release of all the refrigerant. These ruptures are caused by fatigue cracks in the boiler tubing. These fatigue cracks form for two reasons: First, the heating of the boiler by its heat sources causes thermal expansion and contraction along the weld seams. Every time the unit cycles on and off, thermal expansion takes place. The tubing that the factories use isn't heavy enough to handle the stress and eventually forms stress cracks along the welds in the boiler. Second: overheating causes a breakdown of the refrigerant and its additive sodium chromate. The brown sludge is sodium chromate that reached a critical temperature and solidified. Along with the sludged chromate are also flakes of metal from the interior walls of the boiler. When the sodium chromate breaks down, the interior walls of the boiler tubing are destroyed which makes the already too thin tubing even weaker until fatigue cracks form, causing a release of the refrigerant ammonia and hydrogen. There have been several RV fires in recent years linked to the boiler failure in the cooling unit. Even if a fridge fire isn't the end result, the cooling unit is still destroyed and in need of replacing.

How can this type of failure be avoided in the future?
1. Use a boiler built by RV Parts Wholesale. We use heavier tubing in our boilers than any cooling unit builder in the country. Heavier than Dometic, heavier than Norcold, and heavier than other cooling units in the industry. But just using heavier tubing isn't going to make the cooling unit last longer. The boiler must be designed properly so it runs at a safe temperature that won't damage the refrigerant in the system. We have done extensive studies on ammonia boilers and their design. We use that latest, most "state of the art" software to evaluate and graph the performance of our boilers. Our studies have given us a far better understanding of how ammonia boilers work and what they need to last longer. Our heavier boilers are safer than boilers built by any of our competitors. 

2. Control the heat in the boiler: Remember the three things an rv refrigerator needs....must be operated level, has the correct heat input, and has good ventilation. Well, today's recreational vehicles don't always meet these requirements. RV owners are often boon-docking in unlevel parking lots, pulling up and down long steep grades. Many towable campers don't sit level on the tow vehicle. Each of these things will overheat the cooling unit boiler, damaging both the refrigerant and the boiler tubing, thus significantly shortening the life of the refrigerator. The unlevel operation can destroy a cooling unit faster than almost anything else and if extreme enough, can ruin the cooling unit in a matter of hours. Slighter instances will have a cumulative effect on the cooling unit but will shorten the life.  

Why don't today's RV refrigerators last as long as those built 20 years ago? 
  • The way they are quickly, cheaply built 
  • The way they are operated as described above  
  • Ventilation problems from the way they are installed by some rv manufacturers. Explanation: The biggest ventilation problems are from rv refrigerators installed in a slide-out room. An RV owner can do everything right and always level your rv/camper and the refrigerator can fail all of a sudden from overheating due to ventilation problems with the slide-out room. Because the slide-out room doesn't have a roof vent, the refrigerator relies on cooling fans to keep the unit from overheating. If the fans fail or the limit switch doesn't turn the fans on at the right time, the cooling unit can be destroyed very quickly. In extreme heat, even properly operating fans aren't always enough to keep the cooling unit from overheating, especially larger refrigerators like the Norcold 1200, N1200, 1200LRIM, and the Dometic RM7732, 1292, NDR1292, RM1350. 

The standard cost is $65.00/retail unit. 
Some units require us to ship larger boxes and we have to use semi truck freight. Those units require a special rate quote on an individual basis, because they can vary quite a bit from zip code to zip code. 
An order can be cancelled if shipping has not been set up. Once shipped, the order can not be cancelled.
Our  Aftermarket Dometic Cooling Units are available with a limited lifetime warranty.

What is a Lifetime Limited Warranty? It is a warranty to cover manufacturing defects for the useful life of our product to the original purchaser.
Some restrictions apply:Terms and Conditions of Limited lifetime Cooling Unit Warranty.

1. Lifetime Limited Warranty is good for the original purchaser and is only transferable in the first year of ownership. A warranty transfer fee of $100 applies
2. Warranty Registration must be filled out and mailed to us within 30 days of Purchase.
3. Defective cooling unit must be packaged and returned for warranty processing. RV Parts Wholesale will pay shipping first 12 months. After first year, customer is responsible for shipping cost. If cooling unit is found defective under these warranty conditions. RV Parts Wholesale will repair or replace the cooling unit at our discretion. The cooling unit must be removed from refrigerator and shipped to rvcool for warranty repair.

Warranty:Limited Lifetime Warranty covers defects for Original Purchaser (end user) for the useful life of that unit from  date of shipment to original retail customer.  Warranty claims must be made through RV Parts Wholesale with the warranty serial number sticker intact.  RV Parts Wholesale will replace or repair, at its option any defective cooling unit within the warranty period, provided the defective cooling unit is shipped to RV Parts Wholesale freight prepaid and meets the terms described below. 

RV Parts Wholesale is not responsible for damage due to accident, misuse, or repairs made by unauthorized personnel, or acts of God.

We want to stand behind our product and make every effort to correct any problems you might encounter with your purchase. In order to provide our customer service, additional testing or troubleshooting steps may be required to diagnose cooling problems before a warranty claim can be processed. Remember that just because a unit quit working....this doesn't always mean the cooling unit failed,  and in most cases with a little troubleshooting we can help you find the problem and a quick, easy solution.  As described in the troubleshooting and testing pages, a unit needs three things to work properly: CORRECT heat input, LEVEL operation, GOOD ventilation. Examples of conditions not warranted include but are not limited to the following:

Improper installation: 
If the installation instructions for your particular unit are not on our website it is your responsibility to contact RVCOOL  for advice or instructions before proceeding. Contact RV Parts Wholesale for printed instructions not found on website. Failure to follow RV Parts Wholesale instructions may void warranty at the complete discretion of RV Parts Wholesale. Paper instructions are NOT shipped with the cooling unit and must be obtained here on the website or by email. If you have questions concerning the installation of a replacement cooling unit it is your responsibility to contact RV Parts Wholesale for advice or instructions before proceeding. 

Examples of installation problems that will lead to the warranty being voided: 
  • Not sealing the back of the unit with good aluminum foil tape as described in instructions. 
  • Not applying thermal mastic as described by instructions. 
  • Not replacing the fiberglass insulation around the boiler if the old insulation is saturated with yellow from a cooling unit leaking in this area. 
  • New insullation is supplied with replacement cooling unit.

Improper Ventilation
Ventilation must be open with no obstructions preventing air flow through condenser fins to roof vent.         

Improper Operation
  • Running the cooling unit out of level.
  • Applying a heat source not within the original manufacturer's  specifications.            

Cooling Unit Core Alteration 
  • Discharging cooling unit (opening valve stem).

Operating Cooling Uunit in Extreme Cold without a Cold-weather Kit 
Cooling unit should not to be operated at ambient temperature below  20 degree F. without the addition of cold weather kit or the use of the  ARP RV refrigerator control, or suitable heat source to keep cooling unit from freezing up.


EXCEPT for the express warranty stated above, RV Parts Wholesale disclaims all other implied warranties including those of merchantability and fitness. The express warranty is in lieu of all obligations or liabilities on the part of RV Parts Wholesale for damages, including but not limited to special, indirect, or consequential damages arising out of or in connection with the use or performance of the materials. ALL warranties are void on past due accounts, or if RV Parts Wholesale decal is removed from cooling unit.
To start a warranty claim, the customer has to call us or email us with the serial number located on their boiler tank. We will use that number to look up the order and verify their core was returned for a valid warranty. 

After verified, the customer will be provided (verbally or via email) the troubleshooting instructions to eliminate all other variables (such as electrical, gas or other refrigerator issues). If it is determined that the cooling unit is at fault, a replacement unit will be sent out. 
1. A strong ammonia smell inside the box. This would indicate a leak in the evaporator section. If the unit has leaked for an extended amount of time the ammonia smell may no longer be present but you will probably hear a gurgling sound coming from the back of your refrigerator a few minutes after you turn it on. 

2. If the controls are working and the cooling unit is heating up in the back, but there is no cooling taking place inside the box, this could be a sign of a blockage in the boiler section. 

3. If your unit is not cooling but you don't smell ammonia inside the box, look for a yellow powder around or just above the burner located at the back of the unit. This would indicate a leak in the boiler section. Since this leak is outside the box you would rarely smell it inside.  These boiler leaks appear more frequently in the newer Norcold and Dometic cooling units, found in most campers and RVs.