How propane leak detectors work — and why every house with propane should have one

If you've ever smelled that distinct rotten-egg odor near a propane appliance and wondered whether it was really a leak or just your imagination, you're not alone. Out here — whether you're in a farmhouse outside Mountainair, a cabin near Pecos, or a place on the edge of Moriarty with a propane tank in the yard — a working leak detector is one of the cheapest, most effective safety upgrades a household can make. It's also one of the most misunderstood.

Propane detection isn't the same as natural gas detection

Most people who grew up around natural gas assume any "gas detector" works the same way. It doesn't. Propane is heavier than air. When it leaks, it doesn't rise and dissipate — it sinks and pools along the floor, in crawl spaces, and in low corners of a room. Natural gas detectors are built to sense gas near the ceiling, where lighter-than-air methane collects. Put one of those in a propane home and it's essentially decoration.

A true propane leak detector is calibrated to sense propane specifically and is designed to be mounted low — typically 12 inches or less from the floor. This matters even more in New Mexico's rural terrain, where a lot of propane tanks, lines, and appliances sit in mobile homes, crawl spaces, or older additions where a slow leak can go unnoticed for a while before anyone catches the smell.

Where to actually put one

Placement is the difference between a detector that works and one that just hangs on the wall. As a general rule:

• Install one within a few feet of every propane appliance — water heater, furnace, range, dryer
• Mount it low on the wall, near outlet height or lower, never near the ceiling
• Add one near the tank's indoor gas line entry point, if your home has one
• Avoid placing units directly behind furniture, curtains, or in dead-air corners where gas won't reach the sensor
• If you have a basement, crawl space, or lower level where propane could pool, that space needs its own detector

Homes with a single central furnace often need just one or two units. Larger or multi-appliance homes — especially the kind we see a lot of across our 35-mile service radius around Pecos, Mountainair, and Moriarty — usually need coverage in two or three rooms.

Battery-powered vs. hardwired: what actually matters

Both types work, and both meet the same underlying safety standards. The real question is which one fits your household's habits.

Battery-powered detectors are simple to install and don't require an electrician, which makes them a good fit for rentals, sheds, guest houses, or older homes where rewiring isn't practical. Their weakness is exactly what you'd expect: they're only as good as their batteries. In our experience, the units that fail when they're needed most are almost always the ones nobody's tested since Christmas.

Hardwired units, often with battery backup, tend to be more reliable long-term because they're not dependent on someone remembering to swap batteries. They cost a bit more upfront and usually need a licensed electrician for installation, but for a primary residence — especially one that's occupied seasonally or left unattended for stretches, which isn't unusual out here — the extra reliability is often worth it.

Either way, test the unit monthly and replace batteries at least once a year, even if the low-battery chirp hasn't started yet.

What to do when a detector alarms

This is the part every household member should know cold, not just whoever reads the manual.

• Don't light matches, flip light switches, or use anything that could spark
• Get everyone out of the house immediately, including pets
• Don't try to locate the leak yourself or shut off appliances on your way out
• Once you're safely away from the structure, shut off the tank valve if you can do so without going back inside
• Call your propane provider or 911 from outside, not from inside the house
• Don't go back in until a qualified technician has checked the system and cleared it

A leak detector's whole job is to give you those extra few minutes of warning. What you do with that warning is what actually keeps people safe.

A quiet piece of equipment that earns its place

Most of the time, a propane detector sits on the wall doing nothing, which is exactly the point. It's not there to be noticed — it's there for the one night it might matter. As a family-owned company that's been filling tanks and servicing systems across this part of New Mexico for a long time, we'd rather talk you through detector placement now than respond to a preventable emergency later.

If you're not sure whether your home has the right detectors in the right spots, or you want a technician to walk through it during your next delivery or service visit, give us a call at (505) 407-2260 or visit https://southwestpropane.org to schedule a visit.