Stop RV refrigerator fires before they start!


By Russ and Tiña De Maris

Of all the RVing videos on the internet, perhaps the most frightening are the ones that show a rig burning up. You can practically hear the popping, smell the smoke, and feel your heart shudder when you think about how the owner is feeling as his rolling home turns into a pile of ash.

Stop RV refrigerator fires before they start!

Far too often, the finger of cause is pointed at the refrigerator. Too many RVs have turned to smoke and ash because an RV refrigerator overheated, caught fire, then set the whole rig aflame, all in a what seems like the wink of an eye. If there was just some practical way to stop the problem before it ever started.

Enter Paul and Mao Unmack. With 60 years of RVing experience, the Unmacks know about the fun – and headaches – that can attend the lifestyle. They’ve engineered what may be one of the most significant pieces of equipment that can enhance safety and RV refrigerator longevity.

It’s called the Fridge Defend. Their brainchild is also called an ARP – for Absorption Refrigeration Protective Control. It’s not a complicated device – but it proves to be a lifesaver.

The ARP control is wired into the back of a Norcold or Dometic refrigerator, and it monitors the refrigerator’s boiler temperature. If the temperature begins to rise out of a safe limit, ARP shuts the refrigerator down. No excessive heat, no fire. “But where does that leave my fridge full of food?” you ask. ARP continuously monitors the temperature, and when the boiler temperature drops back down into the safe area, it turns the unit back on, and your refrigerator goes back to work cooling your food.

While Fridge Defend’s principal job is to ensure safety, there’s another great byproduct. Most RVers know that operating their RV refrigerator off-level can lead to expensive problems. Even with that knowledge, the number of failed cooling units each year probably puts a smile on many RV repair technicians’ faces. The biggest reason behind cooling unit failure is that off-level operation leads to a gradual deterioration of the unit’s effectiveness. Along with that off-level operation is the generation of excess boiler heat. Fridge Defend detects the heat and protects the cooling unit by shutting it down. No excessive heat – no cooling unit damage.

A brief video found here shows just how the Fridge Defend works.  If you’ve got bandwidth and time, this 17-minute video (below) from an RV seminar goes into far more detail.

Prices for the Fridge Defend system start at less than $150. That might seem steep to some, but consider the cost of replacing just the cooling unit in your fridge; or worse, how much would you be out financially and emotionally if your rig burned up? It’s something worth considering.

We’re looking forward to bringing you our own experiences with installing and day-to-day operation of a Fridge Defend system. Stay tuned!

In the meantime, here is the website for the Fridge Defend.


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jane shure

AH gas refrigerators. Expensive dangerous pieces of junk. The best thing to do with one of these pieces of junk is to pull them out and take them to a gun range and shoot them full of holes. After having one rupture I refuse to have another one. I use a compressor style which is like a home unit that runs off of the battery. To say I hate gas refrigerators is an under statement.


A big thank you to the Unmacks for their invention. In our travels we have seen a travel trailer go up in flames in the middle of the night due to a refrigerator fire. The family got out safely; however, the travel trailer was up in smoke in a matter of minutes. The scary part is the bedrooms where behind the refrigerator. If the Dad hadn’t been up it would have been a lot worse. Y’all make sure the contents of your RV is covered by insurance too.
Thank you again, Unmacks.

Rory R

Thank God for all-electric refrigerators, and yes I do boondock with no power problems.

Bill Zawadiuk

Of Course, that is the ONLY solution, get a residential Fridge installed if you have the room for it …


I purchased one of these units and it works as promised. Great piece of mind not only for the fire aspect, but also the leveling issue. The one drawback is that the installation instructions are only available on line. And if you think the above video is bad, try winding your way through his website to install the device. He is an engineer who needs to hire a consultant to work over the website.


Not sure if we are talking about the same device, but Norcold had a recall due to fires and installed a device that senses the heat and will shut the unit down before it gets too hot. Problem is the device has about a 60% failure rate. When it goes out, most will go to a shop and learn Norcold will not allow any shop to have this device in stock. It must be ordered through them along with the unit serial number. This can take days or weeks. The other solution is using a strong magnet to reset the… Read more »


The video addresses this.

Bob Godfrey

Is there somewhere where I can find statistical data concerning these refrigerator fires? Are most RV fires started by refrigerators or are there other causes I’m unaware of? I’m wondering where there might be a centralized data base for this info. Thanks.

Dennis Foley

Oh, I’m going to buy one, But that is one of the worst videos I’ve suffered through in years!


If you are little bit handy, you can build a similar gadget yourself. All you need is a thermocouple – basically a temperature sensor that triggers an on/off switch (cost around $3 on Ebay). You’ll also need a “project box” to house it ($4 same source). I added a 12 volt computer cooling fan ($10+ depending on how quiet) to the external fridge vent. The thermocouple allows me to set a temperature to trigger the “on” position and the lower temperature at which the fan turns off. The only electrical connection is ground and a positive 12 volt power on… Read more »


Alex, Norcold needs to hire you as a consultant.


Compliment appreciated but not earned. Many YouTube videos show how to make this gadget. As they say, plagiarism is the most sincere form of flattery. Use these search terms to find components on EBay or your favorite electronics store.



12 volt cooling fan – select one the pushes the most air (CFM)

Roger Edington

What temp do you set the fan to turn on?


Excellent Video for those RVers that have Gas / Electric Refrigerators. This safety device is one of those gadgets, that you think would be and should be included in all Gas / Electric Fridges! Unfortunately, this all comes down to Sales and selling, repairing or replacing existing units on current RV’s. I wonder if this seminar told people to turn off the gas when traveling, to prevent fires and other damage. Many RVers don’t realize the hazards of having the Gas Fridge on when traveling. And they leave them on when stopping for Fuel as well, creating an even bigger… Read more »

Tommy Molnar

The article gives the impression these fires happen most often when the fridge’s left on while driving, which enhances the chances of uneven operation. So don’t leave the fridge on while on the move – and the problem is almost eliminated.


Not true Tommy. Fridge movement during driving helps the working fluid return to the boiler rather than hanging up in the cooling tubes as it does when off level and static.

John Fleming

Jeff, Yes, Paul did discuss the safety of the refrigerator being turned off during traveling. He also discussed the possible consequence of off level stops (rest stops, tire changes, etc.) being off level many times.

Nathan Allen