Thursday, June 1, 2023


RV Electricity – RV fire safety THIA interview: Part 1

RV Road Safety

How can we protect our RVs from a fire?

Fewer things are more frightening or devastating than a fire in your RV. While I’m not a firefighter by any stretch of the imagination, many of my high school buddies and even guys who played in my rock bands were either volunteer or paid firemen. The stories they told about fires they worked were fascinating and frightening at the same time. For these heroes (and I classify anyone who runs INTO a burning structure to save your bacon a hero), some of the worst fires they worked involved mobile homes and RVs.

Think about it … You have a confined space stuffed full of combustible material, wrapped in thin metal, and limited egress points. Plus, there are typically propane tanks, plastic jugs of gasoline, and an unknown number of adults, children and pets. Once a fire starts in an RV you have literally seconds to get you and your family out safely, so don’t think you’re going to actually fight that fire with the little 2 1/2 lb. extinguisher hanging in the kitchen cabinet. Its real job is to give you and your family a few more precious seconds to get out safely.

So what can you do to stop a fire once it starts in your RV? Well, there’s a new firefighting system called THIA from a company named Proteng. I interviewed Todd Mullane from Proteng on Friday night. Todd is a retired veteran Fire Chief having served in the United States Air Force, Air National Guard over 30 years, with training from the Air Force Fire Academy, Texas A&M Fire Academy and University of Maryland Fire Academy.

Here are a few highlights from my interview with him. Because it’s an hour-long video, I’m going to edit it into bite-sized 10-minute portions in the next several days and post them one at a time on YouTube over the next few weeks. But here’s what I’ve learned so far based on some the excellent questions you posted. And yes, I’m JMS if you don’t know that already.

Ray Heims – Found it on Google – its those plastic tubes – right?

JMS: Yes, it’s those big plastic tubes filled with a clear liquid. They’re produced in various lengths to provide the right quantity of firefighting gas for the given cubic foot of the area to be protected.

Ray Heims  I thought it was a gas that filled the area and extinguished flame – not a liquid – a liquid would not work well at all.

JMS: While it’s stored in the tubes under low pressure as a liquid, once the environment reaches a specific temperature, the portion of the tube closest to the heat source ruptures and turns into FM-200® gas (a halocarbon) within milliseconds. This sounds like a shotgun going off as the rapidly expanding gas now smothers the flame.

Robert Pulliam: If this is the fire extinguisher in a tube it’s subject to accidentally discharging if kept in a hot place. See Big Truck Big RV YouTube video on this.

JMS: Per my discussion with Proteng, that particular social influencer performed their own installation against PROTENG’s recommended use in a toolbox which contained several tools with lithium batteries. The FM-200® extinguishing agent is not rated for lithium fires (Class D). The proper hardware was not used and the integrity of the fastening system was not at the level to withstand the pressure that is created upon activation. That is why PROTENG does not allow self-installation or lend too much merit to social influencing when it comes to fire and life safety.

Gordon Borgeson: I have this system on my refrigerator and around my diesel engine. My question is about the temperature from the engine.  Will this set off the tubing? How can you tell if tube broke (heat) while driving a diesel pusher with the engine 40 feet behind me?

JMS: There’s a heavy-duty version of THIA that activates at a higher temperature that’s specifically designed for engine compartments. And there’s an optional cab mounted reporting system that will indicate if a tube has lost pressure due to a breach.

Karl Shrader: I read where the entire system has to be replaced every 4 years. Is that true?

JMS: No, the THIA tubes are warrantied for 4 years, but the FM-200® agent has an unlimited lifespan and the plastic tubes should last for many years as long as they’re properly mounted and aren’t subject to abrasion.

Well, that’s it for today. By next Saturday’s RVtravel newsletter I’ll begin posting segments of my video interview with Todd, which will cover topics such as THIA placement options, installation costs, possible environmental harm, and a ton more questions from you all. See you next week.

Email me at mike (at) with your questions.

Let’s play safe out there….



Mike Sokol is an electrical and professional sound expert with 40+ years in the industry. His excellent book RV Electrical Safety is available at For more info on Mike’s qualifications as an electrical expert, click here.



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