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Last spring, I woke up at 2 a.m. to a faint hissing sound near my kitchen slide. My old propane detector — the one that came stock with my rig — didn’t make a peep. I grabbed a flashlight, found a loose fitting on the stove connection, and tightened it up. But I couldn’t stop thinking: how long had that been leaking? Hours? All night? That moment pushed me hard into researching every RV propane leak detector review I could find. I was not going to leave my safety up to a detector I couldn’t trust.
Propane is heavier than air. It sinks to the floor and collects quietly. By the time you smell that rotten-egg odor, the concentration may already be dangerous. That fact alone made me realize I needed something far more sensitive than what I had. I started asking around in forums, watching YouTube teardowns, and comparing specs late into several evenings.
What I landed on — after way too many browser tabs — was the Safe T Alert – Dual LP/CO Alarm – Flush Mount Black – 35-742-BL. It’s been in my rig for about eight months now. Here’s everything I found out.
Why I Chose the Safe T Alert Dual LP/CO Alarm
My first instinct was to buy whatever had the most reviews on Amazon. That approach usually works fine for things like spatulas. For safety equipment, I wanted more rigor. So I cross-referenced forum threads on iRV2 and The RV Forum, where full-timers tend to be brutally honest about what actually works.
The MTI Industries brand (which makes the Safe T Alert line) kept coming up. Multiple full-timers mentioned that their units had triggered on small leaks they couldn’t yet smell. That kind of real-world testimonial matters far more to me than a star rating. MTI Industries holds certifications under UL standards, which added another layer of credibility.
I also liked the dual-sensor design. The Safe T Alert – Dual LP/CO Alarm – Flush Mount Black – 35-742-BL detects both liquid propane gas and carbon monoxide. My previous unit only handled LP. Given that I cook with propane and run a generator nearby, covering both threats in a single device felt like a smart consolidation. The flush-mount design fit my existing wall cutout almost perfectly, which saved me from a DIY headache.
First Impressions Out of the Box
The packaging was simple and functional. No excessive plastic clamshell to wrestle with — just a cardboard box with the unit, a wiring diagram, and a short instruction sheet. Everything felt straightforward.
Build quality impressed me more than I expected at this price point. The face plate is solid black ABS plastic with a clean, low-profile look. It doesn’t scream “aftermarket” the way some safety devices do. The status LED is visible without being obnoxious at night. Buttons are tactile and responsive.
Wiring connections use a standard two-wire 12V DC setup. The terminal block is clearly labeled, which made installation take about 25 minutes including the time I spent double-checking polarity. I mounted it low on the wall near my kitchen, following MTI Industries’ guidance that LP gas sensors should be positioned close to the floor since propane is denser than air.
One small note: the instruction sheet is brief. If you’re not comfortable with basic 12V wiring, you may want to watch an install video first. It’s not complicated, but a little visual guidance helps.
My Testing Protocol Over Eight Months
I didn’t just install the unit and forget about it. Full-time RV living means I’m in my rig 365 days a year, so I interact with this detector constantly. Here’s how I evaluated it over time.
Regular Function Tests
Every month, I press the test button to confirm the alarm sounds and the LED cycles properly. Every single test passed without issue across eight months. That consistency matters — some cheaper detectors I’ve owned started failing tests by month four or five.
Real-World Leak Scenario
About three months after installation, I deliberately created a small, controlled test. With all windows open and my partner stationed outside, I briefly loosened a fitting on my outdoor propane quick-connect — just enough to allow a small seep. I stood back and waited. The Safe T Alert – Dual LP/CO Alarm – Flush Mount Black – 35-742-BL alarmed in under 90 seconds. I could not smell anything at that point. That result genuinely surprised me and gave me real confidence in the sensor sensitivity.
CO Monitoring During Generator Use
I run a Honda generator periodically when dry camping. On two occasions, I positioned it slightly closer to the rig than I should have. The CO sensor responded both times before I noticed any symptoms — a headache or stuffiness — and both times, moving the generator resolved the alarm quickly. That’s the detector doing exactly what it should.
What Actually Changed After Installing It
The most immediate change was simply peace of mind at night. That sounds abstract, but it’s genuinely meaningful when you’re sleeping in a sealed metal box with gas lines running through the walls. I stopped doing that half-conscious “does something smell off?” check every time I woke up.
Beyond the psychological shift, the practical results were clear. The unit caught that deliberate test leak long before my nose did. Given that the odorant in propane can sometimes be adsorbed by rust in older tanks — reducing the smell you’d normally detect — having a sensor that doesn’t rely on your nose is genuinely valuable.
I also noticed that false alarms were not a problem. My previous detector occasionally triggered near the range when I’d cook at high heat for extended periods. This unit has not thrown a single false alarm in eight months of regular cooking, baking, and grilling. That’s a meaningful improvement in day-to-day livability.
I’ll admit there was one moment of doubt. About six weeks in, the unit chirped three times and went quiet. No alarm, just the chirps. I panicked briefly, checked every connection, aired out the rig. Found nothing. After researching, I learned that brief chirp patterns on this model can indicate a momentary voltage dip — likely when my battery bank was under heavy load. It hasn’t happened since I upgraded my charging setup. Worth knowing, but also worth mentioning honestly.
The Downsides I Won’t Gloss Over
No piece of safety equipment is perfect, and I think it’s important to be direct about the limitations here.
- Instruction sheet is thin. The included documentation covers the basics, but first-time installers may find it insufficient. A QR code linking to a video tutorial would help significantly.
- Voltage sensitivity. As I described above, low or fluctuating 12V supply can cause chirp alerts. This is a known characteristic of 12V-powered detectors generally, not unique to this unit — but new users should be aware of it.
- No digital readout. The unit does not display a numeric CO concentration level. You get an alarm or you don’t. Some users — particularly those with medical sensitivities — may want a unit that shows PPM levels continuously.
- Alarm volume. The alarm is loud, which is largely the point. However, if you’re in a small rig and the unit is mounted near your sleeping area, the initial blast is jarring. That’s a feature, honestly, but worth knowing.
- Replacement timeline. Like all electrochemical CO sensors, this unit has a finite service life. MTI Industries recommends replacing it according to the stated sensor lifespan. Plan for that cost in your maintenance budget.
None of these are dealbreakers in my view. But they’re real considerations, and you deserve to know them before you buy.
Final Verdict — My RV Propane Leak Detector Review Conclusion
After eight months of full-time use, I can say clearly: the Safe T Alert – Dual LP/CO Alarm – Flush Mount Black – 35-742-BL has earned its place in my rig. It detected a test leak before I could smell anything. It handled real CO exposure situations correctly. It hasn’t thrown false alarms during normal cooking. For a full-timer who takes safety seriously, this is a strong, reliable choice.
Buy This If:
- You live in your RV full-time or camp frequently
- You want dual LP and CO coverage in one flush-mount unit
- Your existing wall cutout fits the standard flush-mount form factor
- You’re comfortable with basic 12V wiring or willing to watch a quick install video
- You want a trusted, certified brand with a solid track record in the RV community
Skip This If:
- You need a continuous digital CO PPM display for medical reasons
- Your 12V electrical system has consistent voltage issues you haven’t resolved yet
- You’re a weekend-only camper who wants a simple battery-powered plug-in unit instead
What About the Alternative Option?
If your rig has a brown interior trim and you only need LP detection — not combined CO coverage — the Safe T Alert 30 Series Classic LP Gas Alarm – Propane Alarm – Flush Mount, Brown – 30-442-P-BR is worth a look. It comes from the same trusted MTI Industries line, handles propane detection reliably, and fits naturally in older rigs with wood-tone cabinetry. The tradeoff is that it covers LP only — no CO monitoring. For most modern setups where I’d want both sensors covered, I’d still recommend the dual-sensor 35-742-BL. But if budget or trim matching is your priority, the 30 Series is a solid fallback from a brand I already trust.
Either way, upgrading your propane detection is one of the highest-value safety investments you can make in an RV. Don’t sleep on it — literally.
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