Tankless or tank water heater: which is right for a Southwest Florida home?

The question usually comes up the day the old tank starts weeping, the worst time to answer it. A tank heater and a tankless heater are both good products. Which one belongs in your house depends on your panel, your gas line, your water, where the unit sits, and how many people shower at seven in the morning. Preference comes last.

Start with how many fixtures run at once

A tank stores hot water and hands it out until it is gone. A tankless heater makes hot water as it passes through, so what matters is flow: how many gallons per minute it can raise to temperature at once. A shower uses about two gallons per minute, a kitchen faucet less, a filling tub more. Two showers and a dishwasher together in a family home need five to seven gallons per minute, and that is the number the unit is sized to.

Our water arrives warm most of the year, which helps a tankless unit here more than one up north. Even so, the most common tankless complaint is a unit sized for the box and not the house: fine for one shower, lukewarm for two.

For a tank, sizing is simpler: 40 or 50 gallons for most households, larger for a big tub or a full house in season.

What each one needs from your gas line or electrical panel

• Electric tankless. A whole-house electric unit draws a very large current, on the order of three or four 40 amp double-pole breakers, and wants a 150 to 200 amp service with room to spare. Many homes here built before the 1990s have a 100 or 150 amp panel that is already full, and a panel upgrade is an electrician’s job on top of the plumbing.
• Gas tankless. A gas unit needs a lot of gas at once, often 150,000 to 200,000 BTU, which usually means a 3/4 inch line rather than the 1/2 inch line that fed the old tank, plus its own venting. On propane, the tank and regulator must keep up too.
• Electric tank. A single 30 amp double-pole breaker. Almost every home already has it.
• Gas tank. The existing line and flue, checked for size and condition.

If your house is all electric with a full panel and no gas service, which describes many homes in Lee County, an electric tank or a hybrid heat pump tank is usually the practical answer.

Hard water, scale, and descaling

Lee and Collier County water runs hard, and well water in Lehigh Acres, Alva, and eastern Estero runs harder. In a tank, hardness settles as sediment and shortens the tank’s life. In a tankless unit, the same minerals plate the inside of the heat exchanger, where the passages are narrow and the metal is hot, cutting flow, raising error codes, and eventually killing the unit.

A tankless heater in our water needs a descaling flush, circulating vinegar or a descaling solution through it with a small pump, about once a year without filtration and less often with a whole-home filtration or softening system ahead of it. Isolation valves installed with the unit make that a short job. Skip it for a few years and the warranty conversation gets hard.

Garage, exterior wall, or condo closet

• Garage. The most common location here for both. A tank sits in a pan with a drain to the outside; a tankless unit needs the clearances and venting the manufacturer specifies, and where a car is parked, ignition sources have elevation rules an inspector will check.
• Exterior wall. Outdoor-rated gas tankless units are popular here because there is no flue to run and no closet to give up. The concerns are salt air on Fort Myers Beach, Sanibel, and the coastal side of Bonita Springs and Naples, and a working freeze-protection circuit for the one or two nights a year it matters.
• Condo closet. Condos usually have a small closet with an electric tank, a full panel, no gas, and no way to vent, and associations often specify what may be installed, sometimes with a pan alarm or leak shutoff. In most condos the answer is a like-for-like electric tank, and it is worth reading the association’s rules before buying anything.

Lifespan, space, and what happens in a power outage

A tank lasts 8 to 12 years here; a maintained tankless unit around 20. The tankless unit hangs on a wall the size of a suitcase and frees the floor. Those two facts are the core of the tankless argument.

Power outages surprise people. An electric tank without power does not heat, but it holds 40 or 50 gallons of hot water for a day or so, which counts for something after a hurricane. An electric tankless unit is simply off. A gas tank with a standing pilot keeps working with no power at all, the one setup that gives hot showers through a multi-day outage. A gas tankless unit needs electricity for its controls and fan, so it is off too unless it is on a generator.

The case for each

• A tank fits an all-electric house with a full panel, a condo, or a closet with no venting path. It is the simplest replacement and the easiest to service, and for a seasonal resident who uses it four months a year, the longer tankless life buys little. In a hot garage, a hybrid heat pump tank is worth a look: it pulls heat from the air, dries the garage a little, and uses a fraction of the electricity of a standard tank.
• Tankless fits a house with gas service or real spare panel capacity, a large household or a soaking tub that outruns a tank, and an owner who wants the space back or plans to stay fifteen years and replace the heater once instead of twice. With a filter or softener ahead of it and the descaling schedule kept, it is a genuine upgrade.

Either way it is permitted work in Florida, and a tankless conversion adds gas or electrical work with its own inspection. The plumber sizes the unit, pulls the permit, and schedules the inspection; a conversion done without one tends to surface at a home sale or a 4-point inspection.

Send us the age and type of your current heater, whether the house has gas, how many bathrooms you have, and where the unit sits. With that, we can tell you which option fits and what the house needs to make it work.