How often should a propane tank be inspected?

Short answer

Inspect the propane tank and lines once a year, plus a leak check with every delivery. The yearly look is yours: the tank's condition, the regulator, the lines where they run to the house, and a soapy water check at the fittings. The delivery driver does a leak check as part of filling the tank. A professional leak and pressure test, which goes further, costs $75 to $200. Your own inspection takes 15 to 30 minutes and $0 to $10 for a spray bottle.

Why it matters

Propane is stored as a liquid under pressure and used as a gas, and it's heavier than air. A leak doesn't drift away. It pools in low spots, under a deck, in a basement window well, or along the foundation, and waits for a spark. A small leak at a fitting can go on for months, raising your propane bill and filling a low spot with gas, without anyone smelling it unless they walk through the right place on a still day.

The tank and its lines live outside in the weather. Rust eats the tank's shell from the bottom, where water sits. The regulator, which drops the tank's pressure to what the appliances need, has a vent that can clog with insects and ice. Underground lines shift with frost. A yearly inspection finds the rust, the blocked vent and the loose fitting while they're small, and the delivery leak check catches anything that changed between visits.

When to do it more often

The yearly inspection and the delivery leak check are the schedule. A portable cylinder, the kind on a grill, follows its own rule: it has to be requalified 12 years after the date stamped on its collar, and then every 5 years, or the supplier won't refill it.

Do an extra inspection after anything that could have disturbed the system: a vehicle backing near the tank, digging or landscaping along the line's route, a flood, a hard freeze, or a new appliance connected to the supply. And any time you smell gas, that isn't an inspection, that's a leak, and the steps below say what to do.

What you need

A spray bottle of soapy water, a squirt of dish soap in water, which bubbles where gas is escaping

Steps at a glance

Walk around the tank looking for rust, dents, and paint that's bubbled or flaked, especially where the tank meets its legs or the ground.
Look at the regulator under the tank's dome: its vent should point down and be clear of ice, dirt and insect nests.
Follow the line from the tank to the house and check that it's protected where it comes above ground and enters the wall.
Spray soapy water on every fitting and valve you can reach, and watch for growing bubbles.
Check the tank's gauge and note the level, so a drop with no use stands out.
Make sure the area around the tank is clear of brush, stored items and anything that could burn.

You're done when there's no rust that goes past the paint, the regulator vent is clear, and no fitting makes bubbles.

Signs it's overdue

A gas smell, the rotten egg scent added to propane, anywhere near the tank, the line or an appliance.
Rust or dents on the tank.
Hissing at the tank, the regulator or a fitting.
A regulator vent blocked with dirt, ice or a nest.
Dead or yellowed plants along the route of an underground line, which can mean gas is leaking into the soil.

DIY or pro

The yearly look is pro-recommended, but the parts above are safe for an owner, because they're all done by eye and with soapy water, without touching a fitting. What you shouldn't do is tighten, loosen or replace anything on the gas side. That's the supplier's work, and most suppliers include a leak check with every delivery as a matter of routine.

A professional leak and pressure test costs $75 to $200 and is worth asking for every few years, after any work on the system, and whenever your own inspection turns up bubbles, rust that's more than surface deep, or a gauge that drops faster than your use explains. The supplier's technician can also tell you whether the tank itself is due for requalification.

Safety

Gas: if you smell propane, don't touch a light switch, don't start a car, and don't use a phone near the tank. Leave the area, shut the tank's valve if you can reach it without walking through the smell, and call the propane supplier or the fire department from a safe distance. Don't try to find or fix the leak yourself, and don't light anything until a technician has cleared the system.

FAQ

How do you check a propane tank for leaks?

Spray soapy water on the fittings, the valve and the regulator connections. Gas escaping makes bubbles that grow. A smell of gas means stop and call the supplier.

How often does a propane tank need to be recertified?

A portable cylinder is requalified 12 years after the date stamped on it, then every 5 years. A large stationary tank is the supplier's responsibility to inspect.

What does a propane leak smell like?

Rotten eggs or a skunk. Propane has no smell of its own, so an odor is added so leaks can be noticed.

Can I paint a rusty propane tank?

Surface rust can be cleaned and painted with a light color that reflects heat. Rust that pits the metal needs the supplier to look at the tank.