Tankless vs. tank water heater in Austin: the real payback math

Every week somebody calls and says "my plumber friend told me to go tankless" — or "my plumber friend told me to stick with tank." Both can be right, depending on your house. Here's how we walk Austin homeowners through the decision.

The honest tradeoff

Tankless heaters are 2–3x more expensive to install. They take longer (full day vs. half day). They sometimes need a gas line upgrade. They're not free money — but they also last roughly 20 years vs. 10 for a tank, and they cut your water-heating bill by about 30%.

So the question isn't "which is better" — it's "does the math work for THIS house, THIS family."

When tankless wins

• 2+ adults in the house using simultaneous hot water (showers + dishwasher + laundry running at the same time). Tank heaters run out fast in this scenario; tankless never does.
• Your tank is in living space (closet, garage attached to bedroom). The footprint difference is huge — tankless mounts on a wall and recovers 6+ square feet.
• You plan to stay 7+ years. Below that, the ROI doesn't catch up.
• You already need to replace (current tank is dead or dying). The marginal cost of tankless is much smaller than buying tankless to replace a healthy tank.

When tank still wins

• Single occupant or very low hot water demand. The fixed install premium never pays back.
• Old gas line that would need expensive upgrading. Sometimes that doubles the price.
• You're flipping the house in 1–2 years. Buyers don't price-pay for tankless above tank.

The Austin-specific gotchas

Austin water is hard — calcium content varies by zip but it's high enough that we strongly recommend a softener or annual descale on tankless units. Tankless heat exchangers are sensitive to scale; ignored, they fail in 5 years instead of 20. Budget about $30–60/yr in descale labor (or DIY a vinegar flush if you're handy).

Real numbers from our last 50 installs

Average tank install (50-gal gas): $2,400 installed, parts + labor + permits.

Average tankless install (Rinnai RU199iN): $5,200 installed.

Difference: $2,800.

Average gas savings: about $22/mo, or $264/yr.

Payback: ~10.6 years if you're paying out of pocket. With a Rheem MSCB rebate (~$300) and federal tax credit ($600 for ENERGY STAR), payback drops to ~7.5 years. Tankless lasts ~20 years. After payback you're saving the full $264/yr for 12+ years.

If you're going to be in the house long enough to see year 8, tankless almost always wins. If not, tank.

The fastest way to know which one fits your house: call us and we'll run the numbers with you on the phone. No upsell — we sell both.