Tankless vs. Tank: Which Water Heater Should You Choose?

Who usually comes out ahead with each type?

Tanks tend to suit households that need hot water at several fixtures at the same time, homes where the current heater just failed and the budget is tight, and owners who may sell in a few years. Tankless units tend to suit owners who plan to stay a long time, have natural gas already at the heater, use hot water in short bursts, or want floor space back in a cramped utility closet.

The difference comes from how each one works. A storage tank keeps 30 to 80 gallons hot all day and loses heat to the room while it waits, which the DOE calls standby loss. A tankless heater fires only when a hot tap opens, heating water as it passes through a heat exchanger, so nothing is kept warm between uses.

How do the numbers compare?

Two things stand out. The operating cost ranges for gas tank and gas tankless overlap, so the savings depend heavily on the household. And for an all-electric home, HomeGuide puts a hybrid heat pump tank at just $160 to $190 a year, lower than any tankless option in the table.

Will a tankless unit keep up with your household?

Flow is the deciding factor more often than price. The DOE says a tankless unit typically delivers about 2 to 5 gallons per minute and that homes with high demand may need more than one heater. Picture your busiest ten minutes: two showers on the second floor, the dishwasher running, maybe a load of laundry. If those overlap regularly, a single small unit will leave someone with lukewarm water.

Winter makes this harder. When incoming water is colder, the heater has to raise its temperature further, and its usable flow drops. A plumber sizing a unit should ask which fixtures run at the same time and should quote a model rated for the coldest months, not an average day. If one doesn't ask, ask them. You can find plumbers who handle tankless sizing and installs in Winston-Salem, and around Lewisville as well.

What does converting from a tank actually involve?

Swapping a tank for another tank reuses the existing vent, gas line or circuit. Converting to tankless often doesn't. HomeGuide's 2026 installation guide lists the add-ons:

• Labor for a tank-to-tankless upgrade: $600 to $2,500
• Gas line upgrade: $350 to $2,000, since a gas tankless burner needs far more gas while it runs than a tank burner. A plumber offering gas piping work can check whether your line and meter can supply it.
• New venting: $500 to $1,500, or $100 to $600 to replace existing vents
• Dedicated electrical circuit: $250 to $900, or $850 to $1,700 if the panel itself needs replacing

Permits apply as well. The Winston-Salem/Forsyth County Inspections Division's April 2026 schedule sets a $75 minimum plumbing permit and $8 for each gas outlet installed or replaced. Call 336-727-2624 to confirm what your project needs. In Rowan County, the February 2024 schedule lists a tankless water heater permit at $90.

Does tankless pay for itself?

Sometimes, slowly. The DOE says an ENERGY STAR certified tankless model could save $100 or more a year. Suppose the tankless conversion costs $1,500 more than a new tank. At $100 a year, it takes about 15 years to earn that back, which is within a tankless unit's expected life but longer than many people stay in a house. The math looks better when the existing setup already has gas and good venting, and worse when it needs a new gas line, venting and a circuit all at once.

The longer life helps, too. A tank installed today could need replacing once before a tankless unit installed the same day wears out.

Is natural gas an option at your address?

Piedmont Natural Gas covers all of Forsyth and Davie counties and portions of Davidson and Rowan, according to the NC Utilities Commission, though gas mains don't reach every street. The City of Lexington owns its own natural gas system, which serves city residents and customers across Davidson County. Out in rural Advance or the farm roads around Rockwell, many homes have no gas main at all and rely on propane or electricity. Propane tankless units exist, but the same sizing and venting questions apply.

For an electric-only home, an electric tankless heater makes the most sense for a small household or a single remote bathroom. For a full family, compare it against a heat pump tank first.

How does local water affect each type?

Scale is the main threat to a tankless heat exchanger, because minerals coat its narrow passages. Winston-Salem/Forsyth County Utilities reports hardness of 9 to 28 parts per million, averaging 17.5, in its 2025 report, which is soft water. That is good news for tankless owners on city water in Winston-Salem, Kernersville, Clemmons and Lewisville. Flush the unit on the manufacturer's schedule anyway; HomeGuide prices a tankless flush and descale at $75 to $300.

Private wells are less predictable. Forsyth County Environmental Health permits wells in the county's rural areas, and about half of Rowan County residents relied on them as of 2015. Test the water before buying tankless. If a well pump problem near Rockwell or elsewhere has you working on the system anyway, that is a good time to get the test done.

What about upkeep and repairs?

Tanks need a yearly flush and an anode check every 3 to 5 years, per HomeGuide. Tankless units need descaling and an inlet filter cleaning. When a tankless unit breaks, repairs cost more: HomeGuide puts a heat exchanger replacement at $600 to $1,300. Keep the installation receipt and register the unit, since warranty claims usually depend on it.

What should you ask before signing a tankless quote?

1. What flow rate is this model rated for when the incoming water is at its coldest?
2. Does the price include a gas line check or upgrade, new venting and any electrical work?
3. Who pulls the permit, and is the fee included?
4. How often should the unit be descaled, and do you offer that service?
5. What does the manufacturer's warranty require to stay valid, such as registration or proof of maintenance?

A quote that answers all five in writing makes it far easier to compare one plumber against another, and to see whether the extra cost over a tank is worth it for your house.

So which is right for you?

If your tank has just failed and you need hot water this week, a like-for-like replacement is usually fastest; our guide on whether to repair or replace a failed heater helps with that decision, and you can compare tank replacement options in the city. If you have time to plan, gas at the heater, and a household whose peak demand fits within one unit's flow, tankless is worth pricing. Ask for a written quote that lists the unit, every gas, vent and electrical change, the permit and haul-away. You can browse all the towns we connect callers in to find a plumber near you.

If you ever smell gas near a heater, leave the house and call 911 or Piedmont Natural Gas at 800-752-7504 from outside. Lexington residents should call 911 or the City of Lexington's gas utility. Our page on handling a suspected gas leak covers the details.