Tank vs. Tankless Water Heaters for South Florida Homes

When a water heater gives out, most homeowners have to decide quickly: put in another tank, or switch to tankless? Both can be the right answer. Which one fits depends on your home, your household and how much work the switch would take.

Here's an honest look at how the two compare in South Florida homes and condos, plus the signs that tell you it's time to replace what you have.

How each type works

Tank (storage) water heaters

A tank heater keeps a set amount of water hot and ready at all times. When you open a hot faucet, hot water leaves the top of the tank and cold water flows in at the bottom to be heated. If you use up the stored hot water faster than the heater can keep up, you wait for it to recover. Tank heaters come in electric and gas versions.

Tankless (on-demand) water heaters

A tankless unit heats water only as it flows through. There's no stored supply to run out of, but there is a limit on how much hot water it can make at one time. If two showers, the dishwasher and the washing machine all run at once, a unit that's too small for the household will struggle to keep the temperature up. Sizing it for your peak demand is what makes or breaks a tankless install.

What's different about South Florida

Warmer incoming water

The water coming into homes here stays relatively warm all year compared with colder parts of the country. A tankless heater's capacity depends on how much it has to raise the water temperature, so warmer incoming water works in its favor. Tank heaters benefit too and recover faster.

Many homes are all-electric

A lot of homes in our area don't have natural gas service. Whole-house electric tankless heaters draw a lot of power and usually need large dedicated circuits. Some homes would need an electrical panel or service upgrade before one can go in, which can change the decision quickly. Gas tankless units need a properly sized gas line and correct venting. Either way, the cost of preparing the home matters as much as the price of the heater.

Garages, closets and condos

Tank heaters here often sit in a garage, a utility closet or a closet inside a condo unit. A tankless unit mounts on the wall and frees up that floor space. If you live in a condo, check with your association before planning a change. Buildings can have their own requirements about water heater types, electrical loads, drain pans or who is allowed to do the work.

Hurricane season and power outages

This is worth thinking about before you choose:

• Electric tank: stops heating when the power goes out, but the water already in the tank stays warm for a while. That stored water can also serve as a backup supply in an emergency.
• Tankless, gas or electric: needs electricity to run. Gas tankless units use electric controls and a fan, so they won't make hot water during an outage without backup power.
• Gas tank: a conventional model with a standing pilot light generally keeps working without electricity. Models with electronic ignition or power venting need power.

Minerals and scale

Minerals in tap water build up over time in any water heater. In a tank, sediment collects at the bottom and can cause rumbling or popping sounds. In a tankless unit, scale builds up inside the heat exchanger, and manufacturers call for periodic descaling. If you go tankless, plan on that maintenance.

The tradeoffs side by side

Tank water heaters

What works in their favor:

• Usually the lower upfront cost, especially when you're replacing like for like
• Works with the plumbing, electrical and venting you already have
• Plenty of hot water at once, until the tank is used up
• Simple, familiar equipment

What to weigh:

• Can run out of hot water during heavy use
• Keeps water hot around the clock, so some heat is lost while it sits
• Takes up floor space
• Once the tank itself leaks, it has to be replaced

Tankless water heaters

What works in their favor:

• Hot water without waiting for a tank to recover, as long as demand stays within the unit's flow rating
• Compact, wall-mounted design
• No stored tank losing heat while it sits
• Generally a longer service life than a tank when it's descaled regularly

What to weigh:

• Higher upfront cost, especially if the home needs electrical or gas upgrades
• Must be sized for the most hot water your household uses at one time
• Needs regular descaling
• Needs electricity to run, including gas models
• Some people notice a brief burst of cooler water when a tap is turned off and quickly back on

Which one fits your home?

A few general patterns:

• Smaller household, electric home, straightforward replacement: a new tank is often the simplest and most economical choice.
• Household that regularly runs out of hot water, or needs the floor space: tankless is worth a look, as long as your electrical service or gas supply can support it.
• Condo: start with the building's rules and the unit's electrical capacity, then compare options.

There's also a third type worth knowing about: the heat pump water heater, which uses electricity to pull heat from the surrounding air into the water. It needs room and airflow around it, so it won't fit every closet, but it's worth asking about in a warm climate like ours.

The surest way to decide is to have a plumber look at your current setup, your electrical panel or gas line, and how your household uses hot water, then give you a written price for each option you're considering. Our water heater service page covers the repair and replacement work we do.

Signs it's time to replace your water heater

Some water heater problems are simple repairs. Thermostats, heating elements and valves can often be replaced. Others mean the heater is at the end of the road:

• Water leaking from the tank itself. Leaks at fittings or valves can often be fixed, but a tank that's leaking from the body or seams can't be patched.
• Rusty or discolored hot water while the cold water runs clear, which can be a sign of corrosion inside the tank.
• Rumbling, popping or banging from heavy sediment buildup.
• Running out of hot water much sooner than it used to.
• Repairs piling up on an older unit.
• Age. The manufacture date is on the label, often coded into the serial number. Once a tank heater is approaching ten years old, it's smart to start planning a replacement instead of waiting for it to fail on a busy morning.

One more: if the temperature and pressure relief valve on the side of the tank is dripping or discharging, have it checked promptly. That valve is a safety device. Never cap or plug it.

Talk it through with a plumber

If your water heater is acting up or you're weighing a switch, call Father & Son Plumbing at (786) 922-5974. We're a family-owned, licensed and insured company (Florida license CFC1433358) working from our bases in Hallandale Beach and Aventura, and we'll explain your options in plain terms. We're open Monday through Friday and Sunday, 8 AM to 5 PM (closed Saturday). The $49 service call is waived when you go ahead with the repair, and you'll have a written price before any work starts.