Gas or Heat Pump Pool Heater in Florida — Which One, and What Does Each Need Before It Goes In?

Gas or heat pump — which pool heater is better in Florida?

For a pool kept warm most of the year, usually the heat pump; for a pool or spa heated now and then, or fast, gas. That is the line the U.S. Department of Energy draws. A heat pump uses a little electricity to move heat that is already in the outdoor air into the water, and its efficiency is rated as a coefficient of performance (COP) — usually 3.0 to 7.0, meaning 3 to 7 units of heat for each unit of electricity the compressor uses [3]. Heat pump pool heaters cost more to buy than gas pool heaters, but they typically have much lower annual operating costs, and with proper maintenance they usually last longer — 10 or more years [3].

A gas heater burns natural gas or propane in a combustion chamber and passes the pool water over the heat [4]. The DOE calls gas heaters ideal for quickly heating pools, a good choice for pools that are only used periodically, and the one type that can maintain any desired temperature regardless of the weather [4]. New gas models reach 89 to 95% efficiency, and with proper installation and maintenance they typically last five or more years [4].

Pentair’s own heat-pump guide says the same from the other side: heat pumps are meant to maintain a set water temperature, not for instant or fast heating, and it is not reasonable to expect one to perform like a gas heater, which has a much higher output and faster response [6]. Some households run both — Pentair notes that in some regions it can be more economical to run a heat pump in the warmer months and a gas heater in the cooler ones [6].

How fast does each one heat the pool — and does a heat pump work in a Florida winter?

Gas is faster. Pentair says a properly sized heat pump should raise a pool on average about 1°F per hour, depending on air temperature, humidity and water temperature [6]. The sizes tell the same story: the DOE lists standard heat pump sizes of 75,000 to 125,000 Btu, and gas pool heater outputs from 75,000 up to 450,000 Btu [3][4].

A heat pump works while the air is warm enough to give up its heat. The DOE says heat pump pool heaters work efficiently as long as the outside temperature stays above the 45–50°F range, and that the cooler the air they draw in, the less efficient they are [3]. A gas heater does not depend on the air at all [4][6]. That is the line the DOE draws: a heat pump suits a pool kept warm while the air is mild, and gas suits heating a pool quickly, or one that is heated only now and then [3][4].

Pentair’s advice for a heat pump is to set it at the temperature you want and leave it, so it cycles on and off like a home air conditioner [6].

What does a gas pool heater need from the plumber?

A gas supply big enough for it, its own shutoff valve, and a sediment trap at the inlet. Florida’s fuel gas code requires every appliance to have a shutoff valve — in the same room or area, within 6 feet of the appliance, upstream of the union or connector it serves, and with access [2]. Downstream of that valve, as close to the inlet as practical, goes a sediment trap: a tee with a capped nipple pointing down from its bottom opening, unless the appliance has one built in; ranges, dryers, outdoor grills and gas fireplaces are excused, pool heaters are not [2].

The manufacturer adds its own conditions. Pentair’s MasterTemp 125 guide asks for a manual shutoff valve, a sediment trap and a union all outside the heater cabinet, warns against putting the union inside it, and asks for gas pressure at the heater between 4 and 14 inches of water column, with at least 4 inches while it is running [5]. It reminds the installer to check that the meter can supply the heater and every other appliance on it, and to count 3 extra feet of pipe for every elbow when sizing the line [5]. The heater must be disconnected from the gas piping for any pressure test above ½ psi [5]. It also needs a small electrical supply — 120 or 240 volts on a 15-amp circuit for this model — and has to be grounded and bonded [5].

Where the gas pipe comes from, how deep it is buried and how it is pressure-tested and inspected are covered in our article on how a gas line to a pool heater is run, tested and inspected. The photograph at the top of this page is ours, in Westchase: steel gas pipe held off the stucco wall on brackets, a yellow-handle shutoff valve, and next to the heater a pipe dropping to a capped end — the drip leg. The white PVC running beside it is the pool’s water piping.

What does a heat pump pool heater need — power, a disconnect and a pad?

Its own electrical circuit, a disconnect within sight of it, and a level pad that drains. Pentair’s UltraTemp guide lists the supply as 208–230 volts (single-phase on most models, three-phase on some), with a minimum circuit ampacity of 33 to 43 amps depending on model; the rating plate on the unit is the one to follow [6]. The installer supplies a cutout switch that interrupts all power to the unit within line of sight of it, watertight conduit for the supply, and a disconnecting means at least 5 feet from the inside walls of the pool or spa [6]. The unit must be bonded to the pool’s bonding grid with solid copper wire no smaller than 8 AWG [6]. That circuit is electrical work, and together with the clearances above it is part of deciding where the unit can go [6].

A heat pump also makes water. Pentair says condensate drains from the evaporator coil at a steady rate, usually three to five gallons an hour, more in humid weather, so the unit sits on a flat slab pitched no more than ¼ inch per foot, with its drain holes kept clear [6]. It should not sit where a roof without gutters dumps rain into it, or where lawn sprinklers spray it [6]. Pentair says its anchor clamps are required in Florida, to hold the unit to the pad in high winds [6].

The water side is 2-inch plumbing connections; Pentair’s guide calls for a bypass valve where the system flow exceeds 120 gallons a minute [6]. The DOE suggests a qualified pool professional for the installation — especially the electric hookup — and an annual tune-up [3].

How close to the house, windows and pool can a pool heater go?

Near the house but not against it, and not at the pool’s edge. Both Pentair manuals we read say to keep the heater at least 5 feet from the inside wall of the pool or spa, unless a solid fence, wall or other permanent barrier separates them [5][6].

A heat pump needs air. Pentair’s UltraTemp guide asks for at least 24 inches of access at the front and 12 inches on every other side for service and air flow, at least 6 inches from the house wall, and — if it is under a cover or overhang — at least 5 feet of clearance above the top of the unit; it is for outdoor use only, and the guide says not to install it indoors [6].

A gas heater needs room for its exhaust. Pentair’s MasterTemp 125 guide says that under a roof overhang there must be at least 3 feet between the overhang and the top of the vent, with the space open on three sides, and never under any deck; the vent must be 6 inches from the building wall, 4 feet from doors, windows and other openings, and 3 feet above any forced-air inlet within 10 feet [5]. It asks for 36 inches between the heater and an air conditioner or heat pump, and warns that a propane heater must not sit in a pit or low spot, because propane is heavier than air [5]. Those are one manufacturer’s figures for one model — the installation manual for the heater you choose is the one that counts.

The photograph below is from a Palm Harbor job, taken beside where a new heater was going: the backyard pool, its paver deck and, at the right edge, a white lattice screen.

What does the Florida energy code require for a heated pool?

Four things for the heater and one for the pool. Section R403.10 of the 2023 Florida Building Code, Energy Conservation (residential), marked mandatory, sets them [1]:

• An on-off switch: the electric power to the heater must be controlled by a readily accessible on-off switch, either part of the heater and mounted on its outside, or outside it and within 3 feet; working it must not change the thermostat setting, and it is in addition to the circuit breaker (R403.10.1) [1]
• No standing pilot: gas-fired heaters may not have continuously burning ignition pilots (R403.10.1, R403.10.4) [1]
• A time switch: heaters and pump motors need time switches or other controls that turn them on and off on a preset schedule; built-in time switches count (R403.10.2) [1]
• Minimum efficiency: gas- and oil-fired pool heaters at least 82% thermal efficiency (R403.10.4); heat pump pool heaters a COP of at least 4.0 at the standard low-air-temperature test, with an independent lab report (R403.10.5) [1]
• A cover on an outdoor heated pool or spa, unless a heat pump or the sun does most of the heating (R403.10.3) — see the next question [1]

Do I need a pool cover if I heat my pool?

Under Florida’s energy code, yes — unless most of the heat is site-recovered. Section R403.10.3 says outdoor heated swimming pools and outdoor permanent spas must have a vapor-retardant cover on or at the water surface, a liquid cover, or other means proven to reduce heat loss [1]. The exception: where more than 70% of the heating energy over a season comes from site-recovered energy, such as a heat pump or solar, the cover is not required [1]. A pool heated mainly by gas does not qualify for that exception.

Even where it is not required, a cover earns its place. The DOE’s own estimates for an outdoor pool in Miami, heated to 80°F all year, come out at roughly a fifth with a cover of what they are without one — for a heat pump and for a gas heater alike (our arithmetic from the DOE tables) [3][4].

What this means in Clearwater and across Tampa Bay

The Florida Building Code is statewide, so the shutoff valve and sediment trap in the fuel gas code and the switch, timer, efficiency and cover rules in the energy code apply the same way in Clearwater, Tampa, Westchase and Palm Harbor [1][2]. The sections quoted on this page are from the 8th edition (2023).

We have run the gas side of a pool heater — the line, the shutoff, the drip leg and the connection — as on the Westchase job at the top of this page. The photographs on this page are ours, from Westchase and Palm Harbor. If you are choosing between gas and a heat pump, call 727-470-7126 and tell us what fuel the house has now and how you use the pool.

FAQ

Sources

We review and cite. We do not reproduce a paper or a manual — follow the links for the originals.

1. [1]2023 Florida Building Code, Energy Conservation, 8th Edition — Chapter 4 [RE] Residential Energy Efficiency, §R403.10 Pools and Permanent Spa Energy Consumption (Mandatory) — Florida Building Commission / International Code Council · 2023Law / code · §R403.10.1 heaters: readily accessible on-off switch integral to the heater on its exterior or within 3 ft, not changing the thermostat setting, in addition to the circuit breaker; gas-fired heaters no continuously burning ignition pilots; §R403.10.2 time switches for heaters and pump motors (exceptions: 24-hour pump operation required by public health standards, pumps for solar and waste-heat-recovery heating, pumps powered only from onsite renewable generation); §R403.10.3 covers on outdoor heated pools and permanent spas, exception where more than 70% of the season’s heating energy is site-recovered, such as from a heat pump or solar; §R403.10.4 gas- and oil-fired heaters at least 82% thermal efficiency (ANSI Z21.56), no continuous pilots; §R403.10.5 heat pump pool heaters COP at least 4.0 (AHRI 1160, Table 2, low air temperature), independent lab test report. The ICC page renders by script and did not return text to us; the same section text was read on the UpCodes copy of the 2023 FBC Energy Conservation, 8th edition (up.codes/viewer/florida/fl-energy-conservation-code-2023/chapter/RE_4), 2026-10-26
2. [2]2023 Florida Building Code, Fuel Gas, 8th Edition — Chapter 4, Gas Piping Installations (§408.4 Sediment Trap, §409.5 Appliance Shutoff Valve) — Florida Building Commission / International Code Council · 2023Law / code · §408.4: where not incorporated in the appliance, a sediment trap downstream of the appliance shutoff valve as close to the inlet as practical — a tee with a capped nipple in the bottommost opening, or another approved device; illuminating appliances, ranges, clothes dryers, decorative vented appliances, gas fireplaces and outdoor grills excused; §409.5 / §409.5.1: each appliance has a shutoff valve in the same room, within 6 ft of the appliance, upstream of the union, connector or quick disconnect it serves, with access. Text read on the UpCodes copy (up.codes/viewer/florida/fl-fuel-gas-code-2023/chapter/4), 2026-10-26; ICC chapter page confirmed to exist on 2026-10-26
3. [3]Heat Pump Swimming Pool Heaters (Energy Saver) — U.S. Department of Energy · n.d.Government or standards body · heat pumps move heat from the outdoor air into the water; efficient above the 45–50°F range, less efficient as the air cools; COP usually 3.0–7.0; cost more than gas pool heaters but typically much lower annual operating costs; typically last longer than gas, 10 or more years; standard sizes 75,000–125,000 Btu; qualified professional for installation, especially the electric hookup; annual tune-up; Table 1 heating estimates for Miami with and without a cover. The live energy.gov page returned 404 on 2026-10-26; read in the Internet Archive copy of 2026-01-01, 2026-10-26
4. [4]Gas Pool Heaters (Energy Saver) — U.S. Department of Energy · n.d.Government or standards body · natural gas or propane burned in a combustion chamber; ideal for quickly heating pools, a good choice for pools used periodically; can maintain any desired temperature regardless of weather; outputs 75,000–450,000 Btu; some models 89–95% efficiency; typically last five or more years; Table 2 heating estimates for Miami with and without a cover. The live energy.gov page returned 404 on 2026-10-26; read in the Internet Archive copy of 2026-01-01, 2026-10-26
5. [5]MasterTemp 125 Pool and Spa Heater Installation and User’s Guide (P/N 475000 Rev. C 3/2019) — Pentair · 2019Manufacturer's manual · p. 14: check the meter supplies the heater and all other appliances; add 3 ft of pipe per elbow; gas supply 4–14 in w.c., at least 4 in w.c. while running; manual shutoff valve, sediment trap (Figure 6) and union outside the heater panels, union not inside the cabinet; heater disconnected for pressure tests above ½ psi; p. 15 Table 2 pipe sizing; p. 16 outdoor: propane not in pits or low spots, under an overhang at least 3 ft above the vent and open on three sides, never under any deck, 36 in from an air conditioner or heat pump, not within 5 ft of the inside of a pool or spa unless separated by a solid fence, wall or permanent barrier; p. 17 Figure 9 vent 6 in from the building wall, 4 ft from openings, 3 ft above a forced-air inlet within 10 ft; electrical: 120/240 VAC, 15 A circuit, grounded and bonded; read 2026-10-26
6. [6]UltraTemp Heat Pump Installation and User’s Guide (P/N 474099 Rev. P 7/14/16) — Pentair (document hosted by retailer Inyo Pools) · 2016Manufacturer's manual · outdoor use only, do not install indoors; p. 2: 2-in plumbing connections, electrical supply per rating plate, cutout switch within line of sight interrupting all power, watertight conduit, flat pad pitched no more than ¼ in per ft, condensate usually 3–5 gal per hour, avoid roof run-off and sprinklers; p. 3 Location and Clearances: 24 in at the front and 12 in on other sides, 5 ft above under a cover or overhang, 5 ft from the inside wall of the pool or spa unless a 5-ft solid fence or barrier, 6 in from the house wall; anchor clamps required in Florida; p. 8 bonding with solid copper not smaller than 8 AWG; disconnecting means within sight and at least 5 ft from the pool; p. 24 208–230 V (1- or 3-phase by model), minimum circuit ampacity 33–43 A; operating notes: about 1°F per hour on average, meant to maintain a set temperature, not like a gas heater with much higher output and faster response; may be used with a gas heater, more economical in some regions to run a heat pump in warmer months and gas in cooler; flow above 120 gpm needs a bypass; read 2026-10-26