If you own an inground pool, the heater is the difference between swimming four months a year and swimming eight. The best pool heaters for inground pools fall into three families: inverter electric heat pumps that move heat from the air into your water, natural gas heaters that burn fuel for speed, and solar collectors that cost little to run. Heat pumps suit most families, gas suits cold climates and large pools, and solar handles sunny mild regions.
That is the short version. The long version is that sizing matters more than brand, and that a correctly sized heater plus a pool cover behaves very differently from a mismatched pair of marketing numbers. Owners on r/pools frequently report that a heat pump holds a perfect temperature day after day once they accept the slower warm-up, while owners on r/swimmingpools who installed a Raypak gas heater praise the heat and complain about the running cost. Both experiences are real, and both are predictable.
We spent weeks reading spec sheets, owner reviews and installer commentary on all ten heaters below, then grouped them by what they actually do. Every unit here is suitable for a permanent in-ground installation. Three are natural gas models, seven are inverter or standard electric heat pumps, and one of the electric models can also cool your water in the hottest weeks of summer.
One note before we start: nothing on this list is priced here, because pool heater pricing and dealer availability shift constantly. Use the check buttons to see current listings, and read the sizing section further down before you buy anything, since a unit that is too small will disappoint you every single day it runs.
Top 3 Picks for the Best Pool Heaters for Inground Pools (October 2026)
ECOPOOLTECH Ultra Inverter…
- 46360 BTU max output
- COP up to 15.9
- Pools up to 10000 gallons
- Heating and cooling
- WiFi app with automatic defrost
Varpoolfaye 65,000 BTU…
- 65000 BTU with COP 6.6
- 45 dB quiet operation
- Pools up to 21000 gallons
- Freshwater and saltwater ready
- WiFi app control
WARMBLU 23,000 Gallon Inver…
- Pools up to 23000 gallons
- Pure titanium heat exchanger
- Max COP up to 16.0
- Sub-50 dB operation
- App and touch panel control
The ECOPOOLTECH takes the top slot because it is the most complete package we found: a 46,360 BTU verified output, a COP figure of up to 15.9, heating and cooling in one cabinet, built-in WiFi and fittings in the box, all with the largest review base in this roundup at 288 ratings. The Varpoolfaye earns the top rated badge for its 4.4 average and 45 dB noise level, which owners describe as inaudible next to a running filter pump. The WARMBLU is the best value pick if your pool is large, pairing a pure titanium exchanger with a stated maximum COP of 16.0 for pools up to 23,000 gallons.
All 10 Inground Pool Heaters at a Glance
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Every one of these requires a permanent plumbing and electrical hookup, so treat the table as a shortlist rather than a final answer. The deciding factors are your pool volume in gallons, whether natural gas reaches the equipment pad, and how cold your nights get.
1. ECOPOOLTECH Ultra Inverter Heat Pump – The Best All-Rounder
ECOPOOLTECH Ultra Inverter Swimming Pool Heat Pump | Pool Heater for Above Ground and Inground Pool (up to 10000 Gal) | Heating and Cooling | Smart WiFi Control | Automatic Defrost
46360 BTU max output
COP up to 15.9
Pools up to 10000 gallons
Heating and cooling
73 pounds
The Good
- Highest verified output-to-price ratio in the group
- Heating and cooling in one cabinet
- Automatic defrost with an AI control chip
- WiFi app control out of the box
- 1.5 inch hose and PVC fittings included
The Bad
- Requires a hard-wired electrical connection
- About 11 percent of ratings are one star
- Warm-up takes many hours on a large pool
This is the unit we kept coming back to. The Turbo X module is verified at 46,360 BTU maximum heating output, which is unusually high for a cabinet this compact, and the full DC inverter compressor modulates rather than cycling on and off. That variable behaviour is where the efficiency comes from: instead of drawing full power constantly, the compressor ramps up only as far as your water temperature gap requires.
The stated COP of up to 15.9 is the number that changes your electricity bill. COP means the heat delivered per unit of electricity consumed, so a COP near 16 means you get roughly sixteen times as much heat from the same kilowatt-hour as resistance electric heating, and more than a gas burner burning fuel. The manufacturer advertises up to 70 percent lower heating bills compared with conventional heating.
Two details convinced me. The cabinet heats and cools, so in August you can pull heat back out of the water instead of watching it climb. And the fittings are in the box: 1.5-inch hose and 1.5-inch PVC fittings ship with the unit, which removes a surprise trip to the hardware store mid-project.
It weighs 73 pounds, the lightest unit in our list, so moving it onto the pad is a one-person job with a hand truck. Model number WH-kl-01, and the listing covers several pool sizes, so match the size to your gallons before ordering.
What to check before you commit
The most important thing to know is that this is a hard-wired appliance, not a plug-in unit. You need a properly sized circuit and an electrician if your panel lacks one, and that is the single most common surprise first-time buyers report.
Second, know that about 11 percent of its 288 ratings are one star, mostly for early unit failures. On the positive side, the seller backs it with three years of support plus lifetime technical assistance, which is more generous than several name-brand competitors.
Who it suits and who it does not
It suits owners of pools up to 10,000 gallons who want year-round comfortable water, quiet operation and app control, and who do not want a gas line run to the pool. It also suits anyone who wants cooling in hot months rather than only heating in cold ones.
It does not suit a very large pool that needs a fast temperature recovery after a party, and it does not suit anyone hoping to heat a pool overnight. Owners on r/pools describe exactly this trade-off: consistent temperatures, slow ramps.
2. Varpoolfaye 65,000 BTU Inverter Heat Pump – The Top Rated Performer
Varpoolfaye 65,000 BTU Inverter Pool Heat Pump for Inground Pools 220V
65000 BTU heating capacity
COP of 6.6
45 dB operation
Pools up to 21000 gallons
129.7 pounds
The Good
- Highest average rating in the roundup at 4.4 stars
- 45 dB operation is quieter than a filter pump
- Handles pools up to 21000 gallons
- Freshwater and saltwater compatible
- Responsive support that replaced faulty hardware
The Bad
- Many hours needed for a large temperature change
- Factory water adapters can leak at first startup
- App scheduling is less complete than promised
This is the one to buy if your pool sits next to a bedroom wall, a patio dining area or a neighbour’s fence. The published 45 dB is the lowest noise figure among the ten heaters we reviewed, and owners repeatedly describe the unit as inaudible once the circulation pump is running. A 4.4 average across 145 reviews, with roughly 80 percent five-star ratings, is the strongest rating and volume combination here.
Capacity is 65,000 BTU at a COP of 6.6, rated for pools up to 21,000 gallons. That is a meaningful jump over typical entry units and means it can hold a mid-size in-ground pool at temperature without running continuously, which is exactly where a heat pump’s low running cost pays off.
Installation is straightforward: 1.5-inch connectors and a 118-inch power cord are included, and the unit measures 36.3 by 15 by 25.67 inches. The touch control panel runs in inverter mode and adds a one-button fast heat function, plus a WiFi app for remote temperature, scheduling and mode switching.
One detail worth understanding: the water and electrical halves are fully separated, which is a safety design rather than a marketing line, and the same separation is what makes it usable on both freshwater and saltwater systems. Condensation draining from the cabinet during heat exchange and defrost is normal operation, not a leak.
What to check before you commit
Set your expectations on speed. This heater raises temperature gradually rather than in hours, and the manufacturer itself notes that quick jumps are not its strength. If you want a pool warm for a party tomorrow morning, this is the wrong category of appliance.
Also check the factory-installed water adapters. Some owners report a small leak at first startup that resolves once the fittings are tightened, but you should plan to inspect those joints during commissioning. App scheduling is simpler than on some competing units, so do your scheduling at the panel if you need multiple time windows.
Who it suits and who it does not
It suits owners with pools up to about 21,000 gallons who live near neighbours, run a saltwater system, or want to heat on a schedule without babysitting the unit. It is also a strong fit for anyone replacing an older gas heater who wants lower running costs and no gas line work.
It does not suit someone planning rapid recovery, and it does not suit a yard where a 129.7-pound cabinet cannot be positioned with clearance for airflow. The unit needs room to breathe on the pad, not a corner.
3. WARMBLU 23,000 Gallon Inverter Heat Pump – The Best Value for Large Pools
WARMBLU 23,000 Gallons Inverter Pool Heat Pump for Inground Pools 220V
Pools up to 23000 gallons
Pure titanium heat exchanger
Max COP up to 16.0
Sub-50 dB operation
175.6 pounds
The Good
- Largest pool capacity in the inverter group at 23000 gallons
- Pure titanium exchanger resists salt and treated water
- Max COP up to 16.0 cuts long-run cost
- Sub-50 dB operation
- Heating and cooling in one unit
The Bad
- Heavy at roughly 175 pounds so plan the move
- Large temperature changes take a day or more
- Smart Life app pairing is fiddly and the WiFi antenna is weak
Most heat pumps in this roundup top out around 10,000 to 15,000 gallons. The SpringBreath 1.0 system in this WARMBLU is rated for pools up to 23,000 gallons, and it is the only inverter unit here that reaches that far. For a 20,000-gallon in-ground pool, that gap decides whether you need one heater or two.
The heat exchanger is pure titanium with a stated maximum COP of 16.0, and the inverter control runs off an intelligent chip with a dynamic algorithm that matches output to demand. Owners report large temperature gains in about 24 hours of near-continuous run, which is the realistic mental model for a heat pump of this size.
It operates below 50 dB, quieter than a standard refrigerator, and it heats and cools. The app and the modern touch panel both show water temperature and flow status, which is genuinely useful when you want to know whether the system is circulating properly rather than just calling for heat.
Size and weight are the practical concerns. At 175.6 pounds and 28.2 by 17.5 by 43 inches, this needs two people to position, and it comes from FOSHAN GOODHEAT TECHNOLOGY LTD under model KSPF-025L1VUA2. Coverage is a 12-month warranty with lifetime customer support.
What to check before you commit
Flow rate needs a balancing valve. Owners who skip this get heavy condensation and poor results, because the unit is designed for a specific flow range through its exchanger. Confirm your pump and pipe sizing with the manufacturer before the pad is poured around the unit.
The Smart Life app setup is fiddly and the WiFi antenna is weak, so plan to control it from the touch panel in the early weeks. A minority of owners also report immediate fault codes on receipt; check the unit promptly so you are inside the return window.
Who it suits and who it does not
It suits owners of larger in-ground pools in the 18,000 to 23,000 gallon range who want one appliance rather than a pair, who live in a mild or moderate climate, and who value quiet running and low long-term cost over fast recovery.
It does not suit anyone expecting an overnight warm-up, and it is a poor fit in deep cold where the defrost cycle will interrupt heating regularly. It also does not suit a solo installer on a delivery day, given the weight.
4. FibroPool FH270 70,000 BTU Heat Pump – Built for Saltwater and Tight Pads
FibroPool Swimming Pool Heat Pump – FH270 70,000 BTU – for Above Ground and Inground Pools and Spas – High Efficiency, All Electric Heater – No Natural Gas or Propane Needed
70000 BTU all-electric
Titanium heat exchanger
Pools up to 15000 gallons
240V circuit
157 pounds
The Good
- 70000 BTU from a standard 240V circuit
- Handles inground pools up to 15000 gallons
- Titanium exchanger suited to treated and salt water
- Enamel-coated cabinet resists weather and corrosion
- Slim profile fits tight equipment pads
The Bad
- Needs a 240V circuit and hard-wired installation
- Performs best with a pool cover
- Digital panel is less intuitive than analog dials
The FH270 is one of the few high-output heat pumps that still fits on a crowded equipment pad. The cabinet is 38 by 15 by 26 inches with an enamel-coated steel shell, and that slim profile is why owners with older, tight installations keep recommending it. At 157 pounds it is manageable with a second pair of hands.
It moves 70,000 BTU of heat on electricity alone, with no natural gas or propane involved. It handles in-ground pools up to 15,000 gallons, plus above-ground pools up to 27 feet round or 18 by 33 feet oval in mild climates. The titanium heat exchanger paired with a high-pressure compressor is the part that matters most for a saltwater pool.
That exchanger choice is not a detail. Forum owners on pool service boards repeatedly warn that unbalanced chemistry damages exchangers, and that a titanium or cupro-nickel unit tolerates salt systems far better than copper. A 4.3 average from 135 reviews, with about 72 percent five-star ratings, reflects a settled, dependable design.
Controls are a digital temperature display with an optional panel extension, so you can position the readout where it is readable from the pool. One-and-a-half inch fittings are included, and the install is a standard 240V circuit with hard-wiring.
What to check before you commit
Budget for electrical work. This unit requires a 240V circuit and a hard-wired connection, and the electrical part of the project is often larger than the heater portion of the bill. Some buyers also find the digital panel less intuitive than an old analog dial, so read the manual before the plumber leaves.
Plan on using a pool cover. Owners report that temperature retention drops sharply on an uncovered pool, and a cover is what converts this heater from adequate to genuinely cheap to run.
Who it suits and who it does not
It suits saltwater pool owners, anyone without a gas line, and owners of mid-size in-ground pools up to about 15,000 gallons whose equipment pad has limited space. It is a good match for coastal or humid properties where corrosion resistance decides how long the unit lasts.
It does not suit very large pools that need quick recovery, and it does not suit a house with no 240V capacity and no budget to add it. In genuinely cold regions, its heat pump efficiency will fall and defrost cycles will lengthen.
5. Hayward HeatPro 140,000 BTU Heat Pump – The Most Heat Pump Capacity Available
Hayward HeatPro Pool Water Heat Pump Heater for Inground Pools, 140,000 BTU
140000 BTU heat pump
Titanium heat exchanger
Ultra Gold corrosion resistance
320 pounds
40 x 31.5 x 50 inches
The Good
- 140000 BTU is the highest heat pump output in this roundup
- Titanium exchanger resists salt water and chemicals
- Ultra Gold technology targets coastal climates
- UV-resistant body panels
- Hayward pool equipment pedigree
The Bad
- Premium pricing and professional installation expected
- Very heavy at 320 pounds
- About 14 percent of ratings are one star
There is a ceiling on residential heat pump output, and a discussion on troublefreepool put it at roughly 140,000 BTU. This Hayward HeatPro model W3HP21404T sits right at that ceiling, which makes it the rare appliance that can carry a large in-ground pool without a second heater or a gas line.
It pulls heat from the surrounding air and moves it into the water rather than generating it, which is why Hayward describes it as more economical than propane, natural gas or resistance electric heaters for regular use. At 320 pounds and 40 by 31.5 by 50 inches, professional placement is effectively required. Plan the crew and the pad in advance.
Corrosion is the headline feature. Ultra Gold corrosion-resistant technology, a titanium heat exchanger, and UV-resistant body panels impervious to corrosion combine to suit coastal and saltwater installations, and the titanium exchanger is specified for maximum heat transfer with strong salt water resistance.
It is designed specifically for regularly used in-ground pools, which is a good sign of a unit built for the job rather than adapted from an above-ground design. Owners who need serious capacity report consistent, easily maintained water temperature. The 4.1 average from 114 reviews includes about 14 percent one-star ratings, mostly tied to delivery and service experiences rather than heating performance.
What to check before you commit
Confirm your electrical service can handle it. A unit of this size with a compressor needs a properly sized dedicated branch circuit, and a service upgrade is a realistic part of this project rather than an exception.
Also confirm local service coverage. The name carries real value only if there is an authorised technician within driving distance who will honour the warranty. For a marketplace-only brand, the absence of local parts and service is the complaint that shows up repeatedly on owner boards.
Who it suits and who it does not
It suits owners of large in-ground pools who want heat pump running costs without running a gas line, and it suits saltwater or coastal properties where exchanger corrosion decides equipment life. It is the pick for anyone who asked what is the strongest heat pump you can install on a residential pool.
It does not suit buyers who need a fast warm-up, since even a large heat pump works on a multi-hour ramp. It also does not suit a tight budget or a narrow equipment pad, given the cabinet dimensions and weight.
6. Hayward H-Series 200,000 BTU Gas Heater – The Fastest Warm-Up
Hayward H-Series Natural Gas Pool Heater for Inground Pools 200,000 BTU
200000 BTU natural gas
Digital LED self-diagnostic panel
Pools and spas up to 600 sq ft
Low-NOx certified
161 pounds
The Good
- 200000 BTU delivers fast temperature recovery
- Digital LED panel with self-diagnostics aids troubleshooting
- Flexible gas and electric connections from either side
- Built-in 3/4 inch gas connection simplifies fuel line setup
- Reduces circulation pump run time for savings
The Bad
- Natural gas installation needs a licensed line and professional setup
- About 17 percent of ratings are one star
- Gas operating cost runs far higher than a heat pump
Gas heaters exist for one reason: speed. The H-Series W3H200FDN delivers 200,000 BTU of burner output, and when a heat pump would take a day to lift a pool twenty degrees, this appliance does it in a fraction of that time. It suits in-ground pools and spas up to 600 square feet.
The control panel is a digital LED unit with self-diagnostic capability, which means troubleshooting information is on the appliance rather than in a manual. It also reduces the circulation pump run time needed once the water reaches set point, which recovers some of the energy cost of owning a gas heater at all.
Two installation details make it easier to retrofit. Gas and electrical connections are flexible, so they can be plumbed in from either side, and there is a built-in 3/4 inch gas connection for straightforward fuel line setup. The unit is certified low-NOx, which matters for air quality and for local code in some jurisdictions.
It is also described as protecting against corrosion from unbalanced water chemistry, and at 161 pounds with dimensions of 33.3 by 32.8 by 30.6 inches it is a reasonable size to move. The trade-off is running cost: 61 reviews average 4.1, with 17 percent one star, and the recurring complaint among owners is the cost of the fuel itself.
What to check before you commit
Confirm your gas line is the right size before you buy. Forum consensus is emphatic on this point: an undersized gas pipe means the unit will not fire properly and will fail early. Get the pipe run verified by a licensed gas fitter, not by the heater seller.
Understand your usage pattern. This is a tool for heating on demand, not for holding a temperature continuously. If you plan to run it daily through shoulder season, the fuel bill will dwarf what a heat pump costs to run.
Who it suits and who it does not
It suits owners in cold climates, homes with an attached spa, families who entertain and want a warm pool the same day, and anyone whose primary requirement is recovery speed rather than lowest running cost. It also suits a property where a gas line already reaches the equipment pad.
It does not suit homes without natural gas service, and it does not suit owners who want to hold temperature cheaply all season. Anyone planning to install it themselves should know the warranty is not the place to save, because a licensed installer is normally required.
7. MICOE 100,000 BTU Inverter Heat Pump – Heating and Cooling With Strong Support
MICOE 100,000 BTU Inverter Pool Heat Pump for 26,000 Gallon Pools
100000 BTU inverter output
Pools up to 26000 gallons
Heats 46 to 104F and cools 45 to 82F
54 dBA
220 pounds
The Good
- 100000 BTU output covers pools up to 26000 gallons
- Heats and cools in one unit
- Automatic defrost for cooler conditions
- 54 dBA variable speed is quiet against older units
- Support praised for fast email answers and engineer advice
The Bad
- Wiring diagrams are confusing for first-time installers
- Requires a 50 amp breaker and waterproof conduit
- Electrical covers feel flimsy and need drilling
The MICOE MSHP-030Y1 covers a wide operating band: it heats from 46 to 104 degrees Fahrenheit and cools from 45 to 82, with automatic defrost when conditions drop. That dual range is what makes it a genuine season-extender rather than a cold-weather specialist, and 100,000 BTU of inverter output handles pools up to 26,000 gallons, the largest stated pool capacity in our group.
Owners report temperature rises of more than 20 degrees in roughly 48 hours, which is on the faster end of what a heat pump can achieve. At approximately 54 dBA under variable-speed operation, it is quieter than the older fixed-speed units many owners are replacing.
The detail that separates this brand is support. Across 71 reviews averaging 4.1, the dominant theme is company responsiveness: quick email answers, consultations with engineers, and even mailed grounding hardware when a site needed it. Phone support has been unresponsive for some buyers, so email and live chat are the better channels.
The build is a titanium heat exchanger for freshwater pools inside an IPX4-rated, UV-resistant ABS cabinet, with app and digital panel control for monitoring and adjustment. A two-year parts replacement warranty and 24/7 live chat back the coverage. It weighs 220 pounds at 42.9 by 18.11 by 29.1 inches.
What to check before you commit
The electrical documentation is the weak point. It calls for a 50 amp breaker and waterproof conduit, and owners report the wiring diagrams being confusing and the electrical covers feeling flimsy enough to need drilling. If you have never installed a 220V appliance, budget for a licensed electrician.
Also note that the titanium exchanger is specified for freshwater pools. If you are on a salt system, confirm compatibility with the manufacturer before purchase rather than assuming.
Who it suits and who it does not
It suits owners of large freshwater in-ground pools who want heating and cooling from one appliance, who want app control, and who value a company that answers technical questions well. It is a good pick for a family that wants the swim season pushed in both directions.
It does not suit saltwater pools without further confirmation, and it does not suit a buyer who wants heat overnight. In genuinely cold weather, expect the defrost cycle to interrupt heating and the effective output to fall.
8. FibroPool FH255 55,000 BTU Heat Pump – The Most Versatile for Smaller Pools
FibroPool Pool Heat Pump FH255 – Electric – 55000 BTU – Titanium
55000 BTU electric output
Pools up to 10000 gallons
Titanium heat exchanger
Digital touch controls
149.7 pounds
The Good
- 55000 BTU at a modest outlay for a full inground install
- Titanium exchanger handles salt and treated water
- Uses roughly 8 to 16 kWh per day depending on weather
- Quiet operation with easy programming
- Compact enough to store on a rolling base in winter
The Bad
- Underpowered for pools of 20000 gallons and above
- Plumbing connections loosen and need periodic tightening
- Support is hard to reach and some warranty claims refused
The FH255 is the value entry point for an in-ground pool, rated at 55,000 BTU for pools up to 10,000 gallons. It works the same way as any air-source heat pump, drawing warmth from the surrounding air and moving it into the water, which is why it costs so much less to run than a gas burner. Long-term owners report consistent heating and low energy draw.
The energy figure is the number to remember: roughly 8 to 16 kWh per day depending on weather. That range reflects the honest truth about heat pumps, which do their best work holding a temperature in mild conditions rather than driving a rapid change in cold ones.
The titanium heat exchanger is suitable for saltwater and treated systems, and the enamel-coated steel cabinet is built for outdoor installation. Digital touch controls give a clear display for setting and monitoring temperature, and quiet operation makes it a neighbour-friendly choice. At 149.7 pounds and 40 by 14 by 24 inches, it is compact enough to mount on a rolling base for winter storage.
It is frequently recommended as a supplement to solar rather than a replacement for it. Pairing it with a solar array, as some homeowners on owner boards have done, keeps daily electricity use minimal and lets the heat pump handle cloudy stretches. If you are still planning a solar component, our pool solar heater guide covers the collectors that work best alongside a unit like this.
What to check before you commit
Match the unit to your gallons honestly. It is underpowered for pools of 20,000 gallons and above, and an undersized heat pump runs long and hard without ever reaching set point. Owners of large pools who bought at this capacity report continuous frustration.
Plan a light maintenance habit. Plumbing connections can loosen and need periodic tightening, and support has been hard to reach for some buyers, with a few warranty claims declined. If you will not check those joints once a season, choose a different model.
Who it suits and who it does not
It suits owners of smaller in-ground pools under about 10,000 gallons, households that want low running cost without a large outlay, and anyone who already has solar or a good pool cover in place. It also suits owners who want a unit they can roll away for winter storage.
It does not suit large pools, saltwater-free is irrelevant here, but it does not suit very cold climates where a low COP would make it expensive to run. It is a holding heater, not a recovery heater.
9. Raypak 266,000 BTU Gas Heater – The Retrofit Friendly Gas Pick
Raypak 266,000 BTU Digital Electronic Ignition Natural Gas Pool Heater
266000 BTU natural gas
Digital electronic ignition
Intermittent spark pilot safety
210 pounds
44 x 31 x 29 inches
The Good
- 266000 BTU raises temperature about 2 to 3 degrees per hour
- Drop-in style replacement for older Raypak models
- Digital electronic ignition is simple to operate
- Serviceable design with widely available parts
- Largest review base among the gas heaters here
The Bad
- Warranty is voided by self-installation
- Temperature sensor and main board failures around 1.5 to 2 years
- Inlet and outlet sit close together complicating bypass plumbing
The Raypak P-R266A-EN-C brings 266,000 BTU of natural gas output, the highest capacity of any heater in this roundup, and it is the natural choice when you already own an older Raypak. Owners report that existing plumbing and electrical connections matched, which is the single biggest cost saving in any replacement project.
Heating speed is the headline: about 2 to 3 degrees per hour, which is how a pool becomes swimmable this afternoon rather than tomorrow. The digital electronic ignition is straightforward, and intermittent spark ignition with pilot safety control means the pilot fires only when there is a call for heat, so it does not sit burning through the shoulder season.
One clever design choice deserves attention. The unit uses a material that does not retain residual heat after shutdown, which eliminates the need for metal heat sinks and reduces cabinet heat after a run. It is also built to withstand varied weather conditions for outdoor installation, and it weighs 210 pounds at 44 by 31 by 29 inches.
With 170 reviews this has the largest sample of any gas heater here, averaging 4.0 stars. Owners consistently praise heating speed, retrofit ease and the availability of replacement parts, while a meaningful minority report sensor or main board failures after roughly one and a half to two years.
What to check before you commit
Do not self-install if you want warranty coverage. Raypak voided warranties have been reported by owners who did the work themselves, and the failure mode people report most often is a temperature sensor or main board going at one and a half to two years. An authorised installer is the cheap insurance.
Check your bypass plumbing layout. The inlet and outlet are positioned very close together, which complicates the bypass loop and can mean extra fittings, and at least one owner received a unit whose internal heat exchanger drain plug was already broken.
Who it suits and who it does not
It suits owners replacing an older Raypak unit who want the simplest possible swap, families in cold climates who need fast recovery, and households with an attached spa. It is the pragmatic pick when a gas line is already present and correctly sized.
It does not suit anyone trying to minimise running cost, and it does not suit a home without a gas line, since running a new fuel line is the expensive part of this installation. A pool with a low annual heating need is better served by an electric unit.
10. Raypak 105,000 BTU Gas Heater – The Small Pool and Spa Choice
Raypak 105,000 BTU Swimming Pool and Spa Heater – Natural Gas
105000 BTU natural gas
120V 3-prong cord convertible to 220V
Analog thermostat
102 pounds
30 x 27 x 16 inches
The Good
- Lowest capacity keeps running cost modest for small pools
- Heats roughly 2 degrees per hour
- Quiet during operation
- Analog thermostat has no learning curve
- 120V cord avoids hard-wiring for simple setups
The Bad
- Analog dial has no scheduling or remote control
- 105000 BTU limits it to smaller pools and spas
- Some units developed heat exchanger leaks with claims declined
- Thermal cut-off fuse can trip in wind
The Raypak PR106AENC is the simplest appliance here, and simplicity has real value. At 105,000 BTU it heats roughly 2 degrees per hour, which is ample for above-ground pools, smaller in-ground pools and spas where the whole body of water needs only a few degrees of lift. At 102 pounds and 30 by 27 by 16 inches, it is the most manageable gas unit on the list.
Installation is where it differs from the competition. It ships with a standard 120V three-prong power cord, convertible to 220V, so a straightforward setup may not require an electrician at all. The gas hookup uses a 1/2 inch NPT connection located 4 5/8 inches off the ground, and the dial is a plain analog thermostat with no learning curve.
It is also quiet during operation, and it is fully serviceable by design, with the intent of years of operation. That matters for a unit that will sit outdoors through many seasons, and owners report that uncomplicated, no-nonsense controls were exactly what they wanted.
The limits are equally clear. With 36 reviews averaging 4.0, this is the smallest review base in the roundup, which means less long-term evidence behind the design. A few owners report heat exchanger leaks over time with warranty claims declined, and the thermal cut-off fuse can trip in wind, requiring a replacement part.
What to check before you commit
Be honest about capacity. 105,000 BTU is enough for a small in-ground pool or a spa, and not enough for a 20,000-gallon in-ground pool that needs a real temperature recovery. Sizing up to a mid-size pool is the most common regret we see with units in this class.
Consider whether analog controls suit you. There is no scheduling and no remote control, so the heater will not start while you are at work unless you add a timer. If that matters, we have covered pool timers separately, and they pair well with a dial-only appliance like this one.
Who it suits and who it does not
It suits owners of above-ground pools, small in-ground pools and spas who want inexpensive gas heat without complex controls. It is a good match for anyone who wants a straightforward heater they can understand and service themselves.
It does not suit large in-ground pools, owners who want scheduling or app control, and anyone planning long-term daily use where gas fuel cost becomes the dominant expense. For a full-size in-ground pool, move up in capacity or switch to electric.
Gas vs Heat Pump vs Solar: What Type of Heater Is Best?
How Big a Heater Do You Need?
A heat pump is sized roughly at 100,000 BTU of capacity per 10,000 gallons of water, so a 15,000-gallon pool needs a unit in the 100,000 to 150,000 BTU class. A gas heater is normally sized at about 250,000 BTU for the same pool, because it is rated on how fast it can recover rather than on how cheaply it can hold. That single difference explains nearly every surprise buyers have.
Here is how the pool sizes that most often come up map to real heaters from this list. A 16 by 32 foot in-ground pool at average depth holds roughly 15,000 to 16,000 gallons, which suits the Varpoolfaye at 65,000 BTU, the FibroPool FH270 at 70,000 BTU, or the MICOE at 100,000 BTU with room to spare. A 20 by 40 foot pool at average depth is around 30,000 gallons, and at that size a single residential heat pump is undersized, so a gas unit in the 250,000 BTU class such as the Raypak 266,000 BTU is the realistic choice. A spa attached to a pool is a special case, because a 105,000 BTU unit like the Raypak PR106AENC can heat a small pool quickly and then keep the spa hot without overworking itself.
Do not forget the pool cover in the calculation. Owners consistently report that an uncovered pool loses its heat overnight no matter how efficient the heater is, and a cover or solar blanket is the cheapest efficiency upgrade available. If you do not already have one, plan for it as part of the same project.
Which Heat Exchanger Material Matters Most?
For a saltwater pool, the exchanger is the component that decides equipment life. Titanium is the most corrosion-resistant option and is what the FibroPool models, the MICOE and the Hayward HeatPro use. Cupro-nickel sits behind titanium and is common in gas heaters. Copper is the most affordable and the least tolerant of aggressive water chemistry.
Keep water chemistry inside the manufacturer range and the exchanger will outlast the compressor. If your chemistry has drifted, an exchanger is the first thing to be damaged, which is the failure owners on pool service boards describe most often.
Why Do Some Contractors Steer You to Gas?
Contractors are rarely being unreasonable, and the reasons are practical rather than financial. First, a gas line may already reach the equipment pad while your electrical panel has no spare capacity, and the required service work decides which appliance is practical. Second, customers frequently expect gas-like results, and a heat pump that ramps slowly generates a complaint the installer has to handle. Third, defrost cycling in cold weather can produce noise complaints from neighbours, which nobody wants. Fourth, a heat pump sale carries a smaller perceived ticket value, and contractors price their time accordingly.
What the question gets wrong is the assumption that contractors dislike heat pumps. The equipment on this list is where the industry is heading, and several of the units here outperform gas on cost per season by a wide margin for anyone heating on a regular schedule.
What Installation Actually Requires
A gas heater needs a properly sized natural gas line, code-compliant venting, a permit in most jurisdictions and a licensed fitter. Forum consensus is clear that an undersized gas pipe prevents the burner from firing properly and shortens the life of the appliance, so verify the pipe run before you order.
A heat pump needs a 240V circuit and hard-wiring, which on an older home can mean a panel upgrade. It needs no fuel line, no venting and no permit for gas, which is often the decisive advantage in areas where natural gas infrastructure is limited. Both approaches reward a proper plan before the equipment pad is finished. While the pad is open, it is also a good moment to add a pool alarm if young children use the water, and to check the pool lighting so the circuit you are working on has capacity to spare.
How to Get More Heat From What You Already Own
Start with the cover. A pool cover is the single largest reduction in heat loss you can buy, and it works with every heater type in this roundup.
Next, run the circulation pump long enough for the heater to do its job, and use a schedule so heating happens during the warmest, sunniest part of the day. If you want supplemental heat in a sunny climate, a solar array is a good companion to a unit like the FibroPool FH255. Keeping the yard lighting and pool equipment timers on a sensible programme also trims waste; our pool timers guide covers that. Adding underwater lighting you will only use at night is another avoidable load, and you can compare those in our pool lights guide.
Finally, keep the water chemistry steady. Balanced water protects the exchanger, the fittings and the plastic headers, and it is free compared with replacing any of them.
Frequently Asked Questions
How many BTU heaters do I need for a 16×32 pool?
A 16 by 32 foot in-ground pool at average depth holds roughly 15000 to 16000 gallons. Size a heat pump at about 100000 BTU of capacity per 10000 gallons, so a unit in the 100000 to 150000 BTU class fits well, such as the 65000 BTU Varpoolfaye, the 70000 BTU FibroPool FH270 or the 100000 BTU MICOE. A gas heater is normally sized around 250000 BTU for the same pool because it is rated on recovery speed rather than efficiency.
What type of pool heater is best for an inground pool?
A heat pump is best for most inground pool owners who want to hold temperature on a regular schedule in a mild or moderate climate, because it moves heat from the air into the water instead of burning fuel. A natural gas heater is best when you need fast recovery, live in a cold climate, or have an attached spa. Solar collectors are best as a low-cost supplement in sunny regions rather than as a standalone solution.
Is a heat pump better than a gas heater for a pool?
It depends on how you heat. A heat pump wins on holding temperature because it moves existing heat rather than generating it, and a COP of 6.6 to 16.0 means far less energy per degree of heat delivered. A gas heater wins on speed, raising temperature about 2 to 3 degrees per hour so a pool is swimmable the same day. Owners who heat daily usually spend far less on a heat pump; owners who heat occasionally for events usually prefer gas.
What are the downsides of using a heat pump pool heater?
The main drawbacks are slow warm-up, since a large temperature change takes a day or more of near-continuous running, and a drop in efficiency as ambient air cools, with output falling and defrost cycles interrupting heat below roughly 50F. A heat pump also needs a 240V circuit and hard-wiring, which can mean electrical work on older homes. Finally, residential heat pump output tops out near 140000 BTU, so very large pools need gas or more than one appliance.
What size pool heater do I need for a 30000 gallon pool?
At 30000 gallons a single residential heat pump is undersized, because the largest units in circulation top out near 140000 BTU. A natural gas heater in the 250000 to 300000 BTU class is the usual answer, such as the 266000 BTU Raypak, or a two-heat-pump setup if you want to avoid a gas line. In a mild climate, a pair of inverter units can hold the temperature economically once the pool is warm.
Why do some pool contractors steer away from heat pumps?
The reasons are usually practical rather than preference. Many homes have a gas line already reaching the equipment pad while the electrical panel has no spare capacity, so gas is the simpler install. Customers also expect gas-like results and are surprised by a heat pump that ramps over hours rather than minutes. Defrost cycling can cause neighbour noise complaints in cold weather, and some contractors value the larger ticket on a gas job.
The Verdict on Inground Pool Heaters
The best pool heaters for inground pools come down to your gallons, your fuel access and your patience. Choose the ECOPOOLTECH Ultra Inverter as the best all-rounder, the Varpoolfaye if quiet running is your top requirement, the WARMBLU if you have a pool above 18,000 gallons and want a single appliance, and the Hayward HeatPro if you need the most capacity an electric unit can deliver. Add the Hayward H-Series or Raypak gas heater only when fast recovery is a genuine requirement.
Whichever you pick, size it for your pool, budget for a cover, and confirm the electrical or gas work before the equipment pad is finished. That planning is what separates a pool you swim in comfortably from one you argue with. Review the listings for current availability and dealer coverage, and get a licensed installer involved early.