Tank vs. tankless:
the honest comparison.

Not every home should convert to tankless. Here's a candid head-to-head — cost, lifespan, efficiency, total ownership — using real Washington Gas data and our 200+ Montgomery County installs as reference.

Real numbersWashington Gas source data15-year TCONo marketing fluff
Head to head

The tale of the tape.

Each row is sourced from either manufacturer specs, Washington Gas data, Energy Star lab tests, or our installed-base measurements. No cherry-picking.

Traditional

Tank storage heater

50-gal · natural gas · atmospheric vent
Purchase + install price$1,800 – $2,800
Unit lifespan10–15 years
Hot water capacity50 gal, then 30 min recovery
Simultaneous showers1–2 (then depletes)
Floor space required~4 sq ft
Standby heat loss~10% of gas bill
Annual gas cost (family of 4)~$280/yr
Flood risk at end of lifeHigh (50 gal in basement)
MaintenanceAnode rod every 3-5 yrs
Rebates availableMinimal
Modern

Tankless on-demand heater

Navien NPE-240A2 · condensing · direct vent
Purchase + install price$3,895 – $7,495
Unit lifespan20+ years
Hot water capacityEndless · 8-12 GPM
Simultaneous showers2-3 (continuous)
Floor space required~0 (wall-mounted)
Standby heat lossNone
Annual gas cost (family of 4)~$185/yr
Flood risk at end of lifeMinimal (no tank)
MaintenanceAnnual flush (hard water areas)
Rebates availableUp to $1,400 stacked
15-year cost of ownership

The long math — over a realistic tenure.

A tank heater's 10–15 year lifespan means most homeowners replace it once during their time in a home. A tankless lasts 20+, meaning no second replacement. Here's how that plays out.

Year 1 out-of-pocket

Tankless costs $2,000 more upfront

Tank install$2,200
Tankless install (net of rebates)$3,895
Year 1 difference+$1,695
Year 5 cumulative

Gap narrows to $1,220

Tank total cost$3,600
Tankless total cost$4,820
Annual savings$95/yr
Year 15 cumulative

Tankless is $1,400 ahead

Tank total (incl. 1 replacement)$7,200
Tankless total$5,800
Total savings$1,400+
When to stick with tank

When tank is actually the right answer.

We install tankless because that's our specialty — but tankless isn't for every home. Here's when we'd honestly tell you to stick with a tank.

Situation 01

Short tenure planned

If you're selling within 3 years, you won't recoup the higher upfront cost of tankless through energy savings. A like-for-like tank swap at $1,800-2,200 is the rational choice.

Situation 02

Very low hot water use

Single occupant, works from home, rarely uses more than a shower a day and a load of laundry a week? The efficiency gains won't be meaningful. Stick with a standard tank.

Situation 03

Electric-only home, off gas grid

If you don't have natural gas service, an electric tankless is usually underpowered for family-sized households. A heat pump water heater (~$1,600 Pepco rebate) is a better electric solution.

Still on the fence?

Book a free consult and we'll honestly tell you if tankless is the right move for your specific home. We'd rather pass on a job than recommend something that doesn't fit.

15yr
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