An RV safety approach should be holistic, the Fridge Defend for the refrigerator, fire extinguishers, and a GFI for the fridge heaters.
We at Fridge Defend take RV Safety very seriously, here is a check list we feel sets safety priorities based on National Fire Protection Association (NFPA) statistics:
ELECTRICAL -- #1 CAUSE OF RV FIRES (NFPA)
ARPC LLC takes the holistic approach here is an RV safety list:
This image shows an electric heater GFI on the power supply to an RV fridge. GFI or GFCI plugs are generally the same device. One of our customers reported that the Fridge Defend Control turned off their fridge. They turned off the Fridge Defend (do not do this yourself, allow the Fridge Defend to do its job) to restart their fridge. Luckily this event happened at night, thus when the fridge restarted on 120VAC the owner of the RV went out to look and witnessed the bottom of one heater glowing red hot.
It is our opinion that the heater could have shored internally (see next photo). If this is the case, a GFI or GFCI type receptacle may have prevented this type of failure mode. A GFI receptacle on your fridge will shut down the fridge if any short to ground occurs. It just makes good sense to take this safety measure on your Dometic or Norcold fridge. The Fridge Defend detected a problem, and turned off the fridge. The owner made the mistake of bypassing the primary fire protection, the Fridge Defend. If you do not have a Fridge Defend, get a GFI on your fridge 120VAC receptacle, this is a backup and detects heater issues the moment they occur.
This picture is from an RV refrigerator that caught on fire due to an electrical heater internal short. The owner of this RV claimed that the fuse was the factory fuse. If this is the case, enough energy was allowed to blow a hole in the heater which also resulted in the cooling unit being ruptured.
A GFI type receptacle will react much faster to this kind of failure than a fuse or circuit breaker. When we have experienced issues with the 120VAC heater fuse blowing, we have recommended to the customers to install a GFI receptacle. Our customers have reported back that the GFI will trip before the fuse blows. Replacement of the heaters generally solves the GFI tripping or fuse issues.
We encourage you to check your fridge to see if the manufacture has installed a GFI on your fridge outlet. Some manufactures power the fridge from a GFI plug that is located in another part of the RV, such as the bathroom GFI. A GFI receptacle is one part of a package of safety equipment which includes the Fridge Defend by ARP, fire extinguishers, and GFI receptacles in your RV.