Best Natural Gas Pool Heaters

Our Pick and How the List Was Built

A reliable pool heat exchanger ensures your water reaches a comfortable temperature quickly enough to keep the pool usable throughout the season. Consistent heat transfer is the primary goal, requiring a unit that can move significant energy into the water volume efficiently.

The Raypak Natural Gas Millivolt Pool Heater achieves this by delivering a 206,000 BTU capacity for consistent heating. For those needing a more compact footprint, the Raypak Digital Electronic Ignition Natural Gas Pool Heater is a practical choice, while the Raypak PR156AENC Natural Gas Heater serves as a dedicated solution for aboveground pools.

We evaluated 51 pool heat exchangers and selected 5 for this page at Refrigerant Recovery Pro. These options cover a price range from $2799 to $2838, with the median price of the 5 products in our comparison being $2799.

View the scope of this guide to see which products are included in our research.

Check the technical requirements to ensure your pool meets the necessary standards.

Browse our top picks for a quick look at the best-rated gas heaters.

You can find our detailed analysis of the SunQuest SQ-2220-REG performance specs to see how it handles high-capacity heating.

Pool Heat Exchangers Compared Side by Side

Prices are approximate and move frequently – check the current price before deciding. “Not stated” means the manufacturer listing does not give that figure – we do not estimate it.

Among our top picks, the value leader is Raypak Digital Electronic Ignition Natural Gas Pool Heater because it provides 206,000 BTU for $2799.

Each Pool Thermal Exchanger We Picked, Examined One by One

The 3 picks below are reviewed in the same order as the cards above.

Raypak Natural Gas Millivolt Pool Heater

The Raypak Natural Gas Millivolt Pool Heater made this list because it provides a reliable natural gas heating solution with a 206,000 BTU capacity. This output is sufficient for heating a pool at the easier end of the 100,000 to 300,000 BTU range required for standard applications.

What we like: This model provides a 206,000 BTU heating capacity, which measures the total heat energy transferred to the water per unit of time. It features a millivolt system, which generates its own electricity to operate the gas valve without needing a separate power source.

Keep in mind: The 206,000 BTU capacity is only enough for smaller pools or slower heating requirements; you should confirm your pool’s specific volume before ordering.

Raypak Digital Electronic Ignition Natural Gas Pool Heater

We selected the Raypak Digital Electronic Ignition Natural Gas Pool Heater for its high-efficiency design and 206,000 BTU output. It offers a compact footprint and specialized safety controls for gas-powered heating.

What we like: The 206,000 BTU heating capacity matches the millivolt model, while the digital electronic ignition provides a safer spark system. It features a pilot that activates only when a call for heat is made, and the material does not retain residual heat after the unit is turned off.

Keep in mind: This model has a 3.9 rating from 61 buyers, which is lower than the millivolt option despite having similar heating capacity.

Raypak PR156AENC Natural Gas Heater

The Raypak PR156AENC Natural Gas Heater is included as a versatile option for aboveground pool heating. It provides a 150,000 BTU capacity and is built with polyester materials for specific installation types.

What we like: This model features a 150,000 BTU heating capacity and operates on a 240 Volts electrical supply. It is specifically designed for aboveground pool and spa compatibility, featuring 2″ water connections.

Keep in mind: With a 150,000 BTU rating, this unit is at the lower end of the required range for larger pools, and the polyester material is a specific choice for aboveground use.

Which model is best for a large commercial-sized pool vs a small backyard pool?

For a small backyard pool, any of these three models can provide sufficient heat, but the Raypak PR156AENC Natural Gas Heater is a common choice for aboveground setups. None of these models provide the high-output capacity required for a large commercial-sized pool, as those typically require much higher BTU ratings than the 150,000 to 206,000 BTU range found here.

Is it worth buying a high-efficiency model or is the cheapest one okay?

You should choose a high-efficiency model like the Raypak Digital Electronic Ignition Natural Gas Pool Heater if you want to reduce long-term fuel consumption. While the cheaper options may have a lower upfront cost, high-efficiency designs reduce the amount of natural gas required to reach your target temperature, which can lead to lower operating costs over the life of the unit.

Consult the buying guide to understand the key criteria for choosing the right unit.

For a specialized heating method, explore our comparison of top-rated solar dome swimming pool heaters.

How to Choose a Pool Heat Exchanger

Selecting a pool heat exchanger BTU output capacity between 100,000 and 300,000

Select a heating capacity between 100,000 and 300,000 BTU to ensure your pool reaches usable temperatures, as these figures represent the standard range for residential needs. You should prioritize higher output if you have a large volume of water to heat quickly. The Raypak Natural Gas Millivolt Pool Heater and the Raypak Digital Electronic Ignition Natural Gas Pool Heater both provide 206,000 BTU, which sits at the easier end of the required range for standard pools. The Raypak PR156AENC Natural Gas Heater provides 150,000 BTU. How many BTUs do you actually need to heat your pool in 30 degrees? Most standard residential setups require at least 150,000 BTU to maintain a steady rise in water temperature. While Titanium Plate Heat Exchangers are the industrial standard for high-efficiency heat transfer in premium systems, the models we evaluated focus on reliable gas-fired output for home use.

Choosing an ignition system type based on specific gas infrastructure

Choose an ignition system based on your specific gas infrastructure, as the method of sparking the burner dictates how the unit starts and operates. The Raypak Natural Gas Millivolt Pool Heater uses a millivolt system, which generates its own small amount of electricity to power the pilot. In contrast, the Raypak Digital Electronic Ignition Natural Gas Pool Heater uses an electronic spark that activates only when there is a call for heat. This digital system is designed to ensure the material does not retain residual heat after being turned off. The Raypak PR156AENC Natural Gas Heater also utilizes a gas-powered source but does not specify a digital ignition type in its data. We selected these options because they offer different ways to manage the combustion process depending on your available electrical and gas connections.

How home gas line pressure requirements determine heater BTU output

Verify your home’s gas line pressure before ordering, as the flow of fuel determines the BTU per hour, which is the standard metric for comparing heater output. While the Raypak Natural Gas Millivolt Pool Heater and the Raypak Digital Electronic Ignition Natural Gas Pool Heater both provide 206,000 BTU, the specific pressure required to achieve this output is not stated in the data. The Raypak PR156AENC Natural Gas Heater provides 150,000 BTU. Because pressure requirements vary by manufacturer and local utility, you should confirm the required PSI with your gas provider to ensure your lines can support the selected heating capacity.

Comparing heat exchanger material for cost and long-term lifespan

Compare the material of the heat exchanger to balance your upfront cost against the long-term lifespan of the unit. Titanium Plate Heat Exchangers are the industrial standard for high-efficiency, corrosion-resistant heat transfer used in premium systems, but they come at a significantly higher price point than the steel or polyester components found in standard units. The Raypak PR156AENC Natural Gas Heater lists a polyester material, while the other two Raypak models do not specify a material type in their data.

Checking the required venting configuration for safe gas exhaust

Check the required venting configuration to ensure the unit can safely exhaust combustion gases from your specific location. The Raypak Digital Electronic Ignition Natural Gas Pool Heater features a small footprint, which can simplify the placement of the venting hardware. The Raypak Natural Gas Millivolt Pool Heater and the Raypak PR156AENC Natural Gas Heater do not state specific venting dimensions or requirements in their data. Since proper venting is a requirement for all gas-fired pool heat exchangers to prevent carbon monoxide buildup, you must confirm the exhaust path requirements with a qualified installer before purchase.

Use the comparison table to see the technical specifications side by side.

See the audience checklist to find the perfect match for your specific needs.

What Each Job Calls For vs What These Picks State

Match the job you actually need done to the figure it calls for, then check which picks state that figure or more. Where none do, the row says so.

These figures are the levels this category is generally held to, not manufacturer claims. A pick at or above a figure states that number; how it reaches it and the rest of your setup still decide the job, so check them against your own workload before buying.

Who Buys Pool Thermal Exchangers, and What It Really Costs

Review the setup and warranty notes for information on installation and manufacturer support.

Explore the detailed reviews for an in-depth analysis of every featured model.

Find answers to common queries in the FAQ section.

Consider exploring the SunQuest Pool Heater system overview if you need a comprehensive multi-panel setup.

Getting Started with Any of These Picks

Pre-installation requirements for natural gas pool heat exchangers

Each of these pool heat exchangers requires a dedicated natural gas supply to function.

• The Raypak Natural Gas Millivolt Pool Heater requires a thermocouple, a sensor that detects heat to trigger the ignition system.
• The Raypak Digital Electronic Ignition Natural Gas Pool Heater requires a gas pressure regulator to ensure consistent fuel flow to the burner.
• The Raypak PR156AENC Natural Gas Heater requires 240 Volts of power for its electronic components.

Verifying pool heat exchanger arrival dimensions and heating capacity

Warranty coverage and return terms vary by seller and country.

• Confirm the heating capacity matches your requirements, as the Raypak PR156AENC provides 150,000 BTU while the other two models provide 206,000 BTU.
• Verify the physical dimensions, such as the 43 x 31 x 26.3 inches of the Raypak Digital Electronic Ignition model, to ensure it fits your designated space.
• Check the condition of the polyester material on the Raypak PR156AENC to ensure no shipping damage occurred to the exterior.

Perform a dry run of the unit’s power and gas connections the day it arrives to confirm all components are seated correctly before the return window closes.

What Buyers Still Want to Know About Pool Thermal Exchangers

What is the difference between a pool heater and a heat exchanger?

A pool heater is a complete system that converts fuel into heat, while a pool heat exchanger is a component that transfers heat from a primary source, like a boiler, into the pool water. Think of a heat exchanger like a radiator in a car: it doesn’t create the energy, it just moves it from one medium to another. The products we evaluated, such as the Raypak Natural Gas Millivolt Pool Heater, are complete heating units that provide the primary heat source.

Which natural gas pool heater provides enough capacity for a standard 20,000-gallon pool?

The Raypak Natural Gas Millivolt Pool Heater and the Raypak Digital Electronic Ignition Natural Gas Pool Heater both provide 206,000 BTU of heating capacity. This output is sufficient for the lower end of the 100,000 to 300,000 BTU range required to heat a pool using natural gas. The Raypak PR156AENC Natural Gas Heater provides 150,000 BTU, which also falls within the lower end of that required range.

How does the ignition system affect the operation of these gas units?

The Raypak Digital Electronic Ignition Natural Gas Pool Heater uses an intermittent spark ignition pilot safety control, which activates only when there is a call for heat. This differs from the Raypak Natural Gas Millivolt Pool Heater, which utilizes a millivolt system to maintain a pilot light. A pilot light is a small, continuously burning flame that serves as the ignition source for the main burner; in older gas models, this is a common point of failure.

Which model is suitable for an above-ground pool setup?

The Raypak PR156AENC Natural Gas Heater is specifically designed for above-ground pool compatibility and features a polyester material. This model provides 150,000 BTU of heating capacity and is designed for floor mounting. For other configurations, you should confirm your specific pool dimensions and the required flow rate with a qualified installer before ordering.

Who Should Skip These Pool Heat Exchangers

The Raypak Natural Gas Millivolt Pool Heater provides a 206,000 BTU heating capacity. This output is sufficient for heating a pool using natural gas at the lower end of the 100,000 to 300,000 BTU range required for standard operation. The Raypak Digital Electronic Ignition Natural Gas Pool Heater also offers 206,000 BTU. It features an intermittent spark ignition pilot, a safety control that activates the pilot only when a call for heat is detected. This model also uses a material that does not retain residual heat after being turned off.

If you need to heat a large pool with high flow, none of the options on this page provide the 336,000 BTU required for that task. These units are designed for standard residential needs rather than high-volume commercial or large-scale demands.