Inspect your oil tank
Annual · typically August
Why it matters
Oil tanks die from the bottom up. Every fill and every season swing pulls a little moist air into the tank; the water settles under the oil and quietly rusts the floor of the tank from the inside. Outside, the tank can look fine right up until it isn't — which is why the failure mode is a surprise, and why the surprise is expensive.
A typical above-ground tank lasts 15–25 years. If yours came with the house and nobody knows its age, this year's inspection is the one where you find out.
What skipping it costs
$3,000–$30,000
An oil tank fails from the inside out — condensation water sits on the bottom and rusts through where you can't see it. A basement release ruins the space and costs thousands; a leak that reaches soil is an environmental remediation, routinely $10,000–$30,000, and many homeowner policies exclude it. The tank gives warnings for years first — if someone looks.
Two ways to get it done
Do it yourself
You'll need: Flashlight, Paper towel.
Once a year, in good light:
- Legs and footing. Four legs, solid, not rusted thin, sitting on concrete or blocks — not sinking into dirt. A tank tips from bad legs more often than it leaks.
- The bottom seam. Run a paper towel along the underside. Any wet smear that smells like oil is a weep — that's your call-a-pro moment. Blisters or scale flaking off the bottom count too.
- Fittings and the fill/vent pipes. Look for staining below every connection.
- The oil line. Where it runs to the burner — protected, sleeved, not kinked, not lying where it gets stepped on.
- Note the age. Date of manufacture is often on the nameplate. Write it down in your house details.
Ten of these inspections in a row will be boring. That's the point.
Hire it out
$100–$250National fair range — local labor moves this number.
A tank inspection usually rides along with the annual burner service ($100–$250 as a standalone; often folded in for less). The pro adds what you can't: an ultrasonic thickness reading if the tank's age or bottom condition raises questions — a number beats a guess and costs a fraction of a tank.
Know the insurance reality: many homeowner policies exclude oil releases, and some carriers ask the tank's age. A proactive replacement of a 25-year-old tank (~$2,500–$3,500 above-ground) is real money, but it's scheduled, clean money — versus a release, which is the worst check you'll ever write on this house. If you have a buried tank, treat every recommendation as a second-opinion situation; that niche has more fear-based selling than any other corner of home heating.
Ask the tech
- How old is this tank, best guess, and what's its expected life?
- Any weeping at the bottom seam or fittings? Show me.
- Would an ultrasonic thickness test make sense before we talk replacement?
Red flags you're being upsold
- 'Condensation on the tank means it's failing — needs replacement now.' Condensation on a cool tank in summer is physics, not failure. A $150–$250 ultrasonic thickness test settles it with a number.
- A replacement quote over $3,500 for a standard above-ground 275-gallon swap with no complications.
- Pressure to abandon-in-place a buried tank without discussing your state's actual requirements — rules vary, and 'dig it all up' isn't always mandated.
Second opinion time: Any buried-tank remediation quote — always. These range from $1,500 to $30,000+ and the first number you hear is rarely the right one.
The call
DIY the annual look — it's a flashlight and five minutes. The moment you see a wet spot, a weep, or a blister at the bottom seam, hire a pro that week, not that season.