Choosing a Pool Heater in Naples: What Heat Pump, Gas, and Electric Each Ask of Your Electrical System | CoHarbor Electric

A homeowner in Olde Cypress called us the morning after an LCEC outage last fall. His standby generator had kicked on right when it should have, run for about twenty minutes, and then shut itself down. The house went dark again. He’d had the generator for three years without a hiccup.

What had changed was the pool. A few months earlier, he’d replaced an aging gas heater with a new heat pump. Good unit, and cheaper to run. But nobody had added it to the generator’s load management plan. When the power dropped, the heat pump’s compressor kicked on along with both AC systems, and the combined starting load was more than the generator could carry. It did exactly what it was designed to do. It protected itself and shut down.

We added the heat pump to a load-shed module so the generator drops it automatically when the house needs the capacity for AC. The next outage, everything stayed on. The pool water just cooled off a couple of degrees, which nobody minded.

That’s the part of heater shopping nobody talks about. The pool company is focused on BTUs and heat-up times. The manufacturer is focused on efficiency ratings. What the heater does to your panel, your service, and in a lot of Naples homes your generator, usually gets figured out after the fact.

So here’s how the three main options look from the electrical side.

Start With What Your House Already Has

Before we talk about any heater, we look at three things: the panel and service size, whether natural gas or propane is realistic at your address, and whether there’s a standby generator in the picture. In Naples, that third one comes up far more than in most places. After the last several storm seasons, a lot of homes have one, and it changes the math.

We run a load calculation under NEC Article 220 for any significant new load. For pool heaters, the answer varies a lot depending on the type.

Gas Heaters: Light on Electricity, Fast on Heat

Gas heaters, natural gas or propane, need very little from the electrical system. The igniter, control board, and in some models a small blower draw a few amps. Often that’s a small circuit at the equipment pad and not much more.

Why Naples Homeowners Still Choose Gas

Speed, mostly. Gas brings water up to temperature faster than anything else, which makes it the go-to for spas. At a home in Riverstone, the owners wanted to go from warm pool water to hot spa water in well under an hour on winter evenings. A heat pump alone wasn’t going to do that. We wired a small gas heater dedicated to the spa, alongside their existing heat pump for the pool. Electrically, the gas unit added almost nothing.

Gas also plays nicely with generators. Because it draws so little power, a gas heater can usually run during an outage without straining the generator at all, assuming the fuel supply holds up.

What to Know About Gas

Piped natural gas is available in some Naples communities and not in others, so a lot of homes rely on propane tanks instead. The gas line and tank work is done by a licensed gas contractor, not an electrician. Our part is the electrical feed and the bonding. A gas heater’s metal parts still get tied into the pool’s bonding system under NEC Article 680, the same as any other equipment on the pad.

Heat Pumps: Efficient, Popular, and a Real Load

Heat pumps are the most common pool heaters we wire in Collier County. They pull heat from the outdoor air and move it into the water, using far less electricity than an electric resistance heater to deliver the same heat. In a Naples winter, where most days stay well above the point where heat pumps start to struggle, they perform well almost all season.

What a Heat Pump Needs

A typical residential pool heat pump needs a dedicated 240-volt circuit, commonly in the 40- to 60-amp range. The unit’s nameplate spells it out, listing the minimum circuit ampacity and maximum overcurrent protection. We size the circuit to that nameplate, not to whatever breaker happens to be in the panel from the old heater.

On many Naples homes with 200-amp service, a heat pump fits without trouble. On older homes, or homes that have already added a second AC system, a wine room, and an EV charger, it may not. If the numbers don’t work, a panel or service upgrade is usually the answer, typically in the $1,800 to $4,500 range, and a service change involves coordinating with LCEC on their side of the meter.

Heat Pumps That Also Cool

Here’s one that surprises people. Some heat pumps are reversible, meaning they can chill the pool as well as heat it. In August in Naples, when pool water can climb into the low 90s, that’s a genuinely nice feature. At a home in Wyndemere, the owners bought a heat/cool unit specifically so the pool would be refreshing in summer instead of feeling like bathwater.

Electrically, a reversible unit has the same kind of circuit requirements. But it means the compressor might be running hard in the middle of summer, right when your AC is also working hardest. That’s worth factoring into the load calculation, and definitely into any generator plan.

Generators and Heat Pumps

This is the Olde Cypress lesson. A heat pump compressor has a significant starting load. If you have a standby generator, the heat pump either needs to be part of the sizing plan or managed by a load-shed device so it steps aside when the house needs the power. Most homeowners are happy to let the pool go without heat during an outage in exchange for keeping the AC running. The generator just needs to know that.

Electric Resistance Heaters: Simple Units, Heavy Circuits

Electric resistance heaters are basically a big heating element in a box. No compressor, no gas, and they heat the same regardless of air temperature. The units themselves are relatively inexpensive, and that’s what draws people in.

The catch is how much current they pull. A 5.5-kilowatt spa heater draws around 23 amps at 240 volts, which most homes can handle. A full-size pool unit is a different animal. Heaters in the 11- to 27-kilowatt range can draw roughly 45 to more than 110 amps.

What the Code Adds

NEC 680.10 covers electric pool water heaters. Among other things, a heater drawing more than 48 amps has to have its load split into separate circuits of 48 amps or less, each with its own overcurrent protection. So a large resistance heater isn’t one circuit. It’s often two or three, which means more panel spaces, heavier wire, and a load calculation that frequently ends in a service upgrade.

Where It Actually Makes Sense

For heating a whole Naples pool, we rarely recommend resistance heat. A heat pump does the same job for a fraction of the operating cost on your LCEC bill. Where resistance heaters make sense is small water volumes, like a compact spa, or a situation where a heat pump simply won’t fit. Most self-contained hot tubs already have one built in.

And on a generator, a large resistance heater is almost always the first thing to exclude. It’s too much load for too little benefit during an outage.

The Short Version

If you want the least electrical impact, gas is the lightest by a wide margin, provided you have or want a gas supply. Heat pumps land in the middle, usually a single 240-volt circuit around 50 amps, with the best operating cost for most Naples pools. Electric resistance heaters demand the most, from a manageable 23 amps for a small spa unit to 100-plus amps split across multiple circuits for a full-size pool heater.

A lot of the nicer setups we see around Naples combine two. A heat pump handles the pool day to day, and a small gas heater gets the spa hot fast. It’s a practical pairing, and electrically it’s easy to live with.

Where Heater Installs Go Wrong

Most of the problems we fix trace back to the heater being chosen before anyone looked at the electrical side. The common ones:

• A new heat pump landed on an old heater circuit that doesn’t match its nameplate
• A large resistance heater ordered without realizing it needs multiple circuits and possibly a service upgrade
• A heat pump added to a home with a standby generator and no update to the load plan
• A new heater never tied into the pool’s bonding system
• Disconnects placed where they’re hard to reach, or too close to the water
• No permit because the new heater “just replaced” the old one

Heater work in Naples typically requires an electrical permit through Collier County, or through the City of Naples building department if the home is inside city limits. Gas units also need their own permit, pulled by the gas contractor. It’s worth doing correctly, since pool equipment is one of the things buyers’ inspectors and insurers look at closely.

If you want more detail on how the circuit itself gets built, our Naples pool equipment wiring guide covers wire gauge, conduit, and disconnect placement. For the full code picture around the pool, including bonding and GFCI protection, see our guide to electrical requirements for pools in Naples homes.

Before You Order, Have Us Take a Look

It saves a lot of trouble to have an electrician check the panel, and the generator if there is one, before the heater gets ordered. One visit is usually enough to tell you which heater types your home can realistically support and what each would take to install.

Get Your Naples Pool Heater Wired by Coharbor Electric

Whether you’re choosing between a heat pump and gas, adding a spa heater, or trying to fit a new heater into an existing generator plan, Coharbor Electric can help you make the call with real numbers. We’re licensed and insured, and we install pool and spa heater circuits, load-shed connections, and panel upgrades throughout Naples and Collier County, from Olde Cypress and Wyndemere to Riverstone and the communities in between.

We’ll check what your home can handle, give you an honest recommendation, and wire the heater to its nameplate and to code, with the permit handled. We can’t promise the pool stays warm during an outage. We can make sure the lights and AC do. Give Coharbor Electric a call to schedule a pool heater electrical assessment.