Water
Tankless or Tank Water Heaters
A tank stores hot water and is cheaper to install. A tankless unit heats on demand, takes less space and lasts longer, but usually needs electrical or gas work. Hard water affects both.
Get a written assessmentIs a tankless water heater worth it?
A tankless unit heats water on demand, takes up far less space and generally lasts longer than a tank. It also usually needs electrical or gas upgrades to install, which is why the answer depends more on your house than on the equipment.
Florida has one genuine advantage here. Incoming groundwater is warmer than it is in most of the country, so a tankless unit has less work to do to reach temperature and can deliver more flow than the same unit would up north.
The catch is almost always the infrastructure. An electric tankless unit of any real capacity draws heavily, and many homes need panel or circuit work to support one. That is the number that surprises people, not the price of the unit.
01
How they compare
Storage tank
- Lower cost to install, and usually a straight swap
- Simple, familiar, and serviceable by anyone
- Delivers a fixed amount of hot water before it needs to recover
- Keeps the stored water hot whether you use it or not
- Takes up floor space in a garage or closet
- Generally the shorter service life of the two
Tankless
- Heats on demand, so hot water does not run out on time
- Mounts on a wall and frees the floor space
- No standby loss from keeping a tank hot
- Generally the longer service life of the two
- Usually needs electrical or gas upgrades to install
- Output is limited by flow rate, so simultaneous demand has a ceiling
02
What decides it in a Florida house
Incoming water temperature
Florida groundwater arrives warm, so a tankless unit has a smaller temperature rise to produce. The same unit delivers more usable flow here than it would in a cold climate.
Electrical capacity
Whole house electric tankless draws heavily and often needs multiple dedicated circuits and available panel capacity. This is the most common reason a tankless project costs more than expected.
Gas availability
Gas tankless is common where gas is already at the house. Where it is not, running a line or setting propane is a project of its own.
How the household uses water
A house that runs two showers and a washing machine at once is asking for flow rate. A house whose complaint is running out of hot water is asking for on demand. Those point the same way. Peak simultaneous demand is the limit to check.
Space
Getting a tank out of a garage corner or a hallway closet is a real gain in a Florida house, and it is often what actually sells the upgrade.
Hard water
Scale is the main enemy of a tankless heat exchanger, and it shortens a tank heater too. On hard Florida water, treatment ahead of either one protects the investment.
03
The hard water problem
Every time hard water is heated, calcium comes out of solution and deposits on the hottest surface it touches. In a tank that is the element or the burner surface, and in a tankless unit it is the heat exchanger, which is the expensive part.
This is why the water heater conversation and the water treatment conversation belong together in Florida. Installing a tankless unit on untreated hard water and then not descaling it is the fastest way to be disappointed by good equipment.
- Ask whether the tankless unit needs periodic descaling and how often
- Ask whether isolation valves for flushing are included in the installation
- Have the water hardness tested before choosing equipment
- Consider treatment ahead of the heater rather than after the failure
- Confirm what the manufacturer warranty says about scale damage
Installations are performed by independent Florida licensed contractor(s). Nova Structa does not perform installation work.
Questions we get on this
- Is a tankless water heater worth it?
- It heats on demand, frees up floor space and generally lasts longer than a tank. Whether it is worth it in your house usually comes down to electrical or gas capacity, since that is what drives the installation cost, and to whether your household's peak demand fits the unit's flow rate.
- Do tankless water heaters work well in Florida?
- Florida is a good climate for them. Incoming groundwater is warm, so the unit has a smaller temperature rise to achieve and delivers more usable flow than the same unit would in a cold state.
- Will a tankless water heater need an electrical upgrade?
- Whole house electric tankless units draw heavily and frequently need dedicated circuits and available panel capacity. That work, not the unit itself, is usually what makes the project cost more than a tank replacement.
- Can a tankless water heater run out of hot water?
- Not by time, but it has a flow rate ceiling. Run enough fixtures at once and the unit cannot heat all of it to temperature. Sizing is done on peak simultaneous demand rather than on the size of the house.
- How long does a water heater last in Florida?
- Hard water shortens both types, because scale deposits on the hottest surface every time water is heated. Tankless units generally outlast tanks, and both do better when the water is treated and the unit is maintained.
- Why does my hot water smell like rotten eggs but the cold does not?
- That points at the water heater rather than the supply. It is a common issue in Florida and the anode rod is usually involved, so it is worth having the heater looked at before assuming the well or the utility is the cause.
Next step
Size it to your house
Peak demand, electrical capacity and water hardness checked together, so the recommendation fits the house rather than the catalog.
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