Pool Heaters & Heat Pumps
Best Inground Pool Heater (2026): 5 Picks Compared
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The AQUASTRONG leads this list for inground pools: it pairs heating and cooling with app control at 35,000 BTU and carries a 3-year warranty. For larger pools, the POOLTOHOT offers 90,000 BTU for pools up to 28,000 gallons.
Starting out? See the main guide: Best Pool Heater
Top picks at a glance
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Best OverallAQUASTRONG Swimming Pool Heater for Above Ground9.8 View on Amazon -
Runner-UpNATURAQUELL Inverter Pool Heat Pump9.6 View on Amazon -
Most Heat OutputPOOLTOHOT Pool Heater for Inground Pools9.5 View on Amazon -
Also GreatGRAT 75,000 BTU Full Inverter Pool Heat9.3 View on Amazon -
9.2 View on Amazon
Compare the specs
Ranked on heat output, phone app control from each listing, plus how many buyers have rated it. A dash (—) means we could not confirm that figure from the listing.
| Pick | Heat output | Phone app control | Weight | Warranty |
|---|---|---|---|---|
| 1. AQUASTRONG Swimming Pool Heater for Above Ground | 35,000 BTU | Yes | 116.84 lb | 3-year |
| 2. NATURAQUELL Inverter Pool Heat Pump | 55,000 BTU | Yes | 107 lb | 8-year |
| 3. POOLTOHOT Pool Heater for Inground Pools | 90,000 BTU | Yes | 179 lb | 3-year |
| 4. GRAT 75,000 BTU Full Inverter Pool Heat | 75,000 BTU | Yes | — | — |
| 5. TURBRO 33,000 BTU Inverter Swimming Pool Heat | 33,000 BTU | Yes | — | 2-year |
AQUASTRONG Swimming Pool Heater for Above Ground
It leads this list with dual-mode heating and cooling, app control and a 3-year warranty, at 35,000 BTU.
- Heat output: 35,000 BTU
- Phone app control
- 3-year warranty stated
Good for
- Owners of inground pools who want app control
- Buyers who want heating and cooling in one unit
Skip it if
- You need more than 35,000 BTU of heat output
- You need a unit under 116.84 lb
It heats from 47 to 104 degrees and cools from 47 to 83 degrees, with a COP of 15.8. Noise is 48 dB, and the defrost cycle runs every 40 minutes and finishes in 5 minutes. It connects with a 1.25 inch and 1.5 inch hose adapter, a 1.5 inch adapter conversion kit and a 1.5 inch PVC pipe converter. It has a 3-year warranty.
NATURAQUELL Inverter Pool Heat Pump
It pairs 55,000 BTU with heating and cooling for pools up to 16,000 gallons, plus an 8-year warranty.
- Heat output: 55,000 BTU
- Phone app control
- 8-year warranty stated
Good for
- Owners of pools up to 16,000 gallons
- Buyers who want a long warranty term
Skip it if
- You need more than 55,000 BTU of heat output
- You need a unit under 107 lb
It heats in outdoor air from 5 to 104 degrees and cools from 59 to 109.4 degrees, with a COP up to 16. Noise is rated at 52 dB(A) with IPX4 protection, and it uses a titanium heat exchanger. It connects with 2 inch inlet and outlet connectors that adjust to 1.25 inch and 1.5 inch pool hoses, and the package includes a 6.6 ft drain pipe, a drain pipe connector and 4 rubber shock absorbers. It has an 8-year warranty.
POOLTOHOT Pool Heater for Inground Pools
It holds the most heat output here at 90,000 BTU, for pools up to 28,000 gallons, with heating and cooling.
- Heat output: 90,000 BTU, the most here
- Phone app control
- 3-year warranty stated
Good for
- Owners of pools up to 28,000 gallons
- Buyers who want the most heat output in this list
Skip it if
- You need more than 90,000 BTU of heat output
- You need a unit under 179 lb
It heats from 47 to 109 degrees and cools from 47 to 83 degrees, with a COP of 15.8. Noise is 50 dB, and it uses a titanium heat exchanger with an ABS plastic housing and intelligent auto-defrost. The maker advises running it 24 hours in advance and keeping the pool covered. It must be installed by a certified electrician, and it has a 3-year warranty.
GRAT 75,000 BTU Full Inverter Pool Heat
It covers pools up to 21,000 gallons at 75,000 BTU, with WiFi and Bluetooth app control and automatic defrost.
- Heat output: 75,000 BTU
- Phone app control
Good for
- Owners of pools up to 21,000 gallons
- Buyers who want Bluetooth pairing plus WiFi control
Skip it if
- You need more than 75,000 BTU of heat output
- You need coverage past 21,000 gallons
It heats from 46 to 104 degrees and cools from 45 to 82 degrees, with a titanium heat exchanger for freshwater and saltwater pools. Noise is approximately 50 dB, and the UV-resistant ABS housing stands up to outdoor installation. Bluetooth is required for initial device pairing, while a 2.4GHz WiFi connection enables remote control and monitoring. The maker recommends a pool cover to reduce heat loss.
TURBRO 33,000 BTU Inverter Swimming Pool Heat
It suits pools up to 10,000 gallons at 33,000 BTU, with a timer, WiFi control and a 2-year full machine warranty.
- Heat output: 33,000 BTU
- Phone app control
- 2-year warranty stated
Good for
- Owners of pools up to 10,000 gallons
- Buyers who want a programmable timer and WiFi control
Skip it if
- You need more than 33,000 BTU of heat output
- You need a pool larger than 10,000 gallons
It sets water from 46 to 104 degrees in outdoor air from 5 to 109 degrees, with a COP up to 15.8 and a programmable timer. It uses a titanium heat exchanger and a four-way valve for switching between heating and cooling modes. It suits pools up to 10,000 gallons, with a maximum size of 20 foot round or 12 foot by 24 foot rectangular. It has a 2-year full machine warranty and a 5-year compressor warranty.
How to choose
Match output and gallons to your pool
Heat output and pool gallons are the two numbers that decide fit. The TURBRO covers pools up to 10,000 gallons at 33,000 BTU, the NATURAQUELL up to 16,000 gallons at 55,000 BTU, the GRAT up to 21,000 gallons at 75,000 BTU, and the POOLTOHOT up to 28,000 gallons at 90,000 BTU. Compare those figures against your pool's gallons before choosing, and check the heating range each maker gives.
Heating and cooling ranges
All five picks heat and cool, so check the ranges against your climate. The AQUASTRONG heats from 47 to 104 degrees and cools from 47 to 83 degrees, the POOLTOHOT heats from 47 to 109 degrees and cools from 47 to 83 degrees, and the GRAT heats from 46 to 104 degrees and cools from 45 to 82 degrees. The NATURAQUELL heats in outdoor air from 5 to 104 degrees and cools from 59 to 109.4 degrees. The TURBRO sets water from 46 to 104 degrees in outdoor air from 5 to 109 degrees.
App control, defrost and upkeep
All five picks offer app control for adjusting temperature and setting schedules. For cold weather, look at defrost: the AQUASTRONG runs defrost cycles every 40 minutes that finish in 5 minutes, the NATURAQUELL uses automatic 4-way valve defrost, and the GRAT has built-in automatic defrost. The POOLTOHOT maker advises running it 24 hours in advance and keeping the pool covered for better heat retention.
FAQ
What size pool heater do I need for an inground pool?
Compare heat output and gallons. The TURBRO covers up to 10,000 gallons, the NATURAQUELL up to 16,000 gallons, the GRAT up to 21,000 gallons, and the POOLTOHOT up to 28,000 gallons.
Do these pool heaters also cool the water?
Yes. All five heat and cool: the AQUASTRONG cools from 47 to 83 degrees, the POOLTOHOT cools from 47 to 83 degrees, and the GRAT cools from 45 to 82 degrees.
What warranties do these pool heaters carry?
The NATURAQUELL carries an 8-year warranty. The AQUASTRONG and POOLTOHOT carry 3-year warranties. The TURBRO carries a 2-year full machine warranty and a 5-year compressor warranty.
Can I control these pool heaters from my phone?
Yes. All five offer app control: the AQUASTRONG, NATURAQUELL, POOLTOHOT, GRAT and TURBRO each pair with a phone app for adjusting temperature and settings.
