10 Best Pool Gas Heaters 2025 in the United States

The Hayward W3H400FDN is a powerful gas pool heater, boasting a robust 400,000 BTU output which makes it suitable for large in-ground pools and spas. One of its standout features is the durable cupro nickel heat exchanger, designed to resist corrosion and ensure longevity, which is particularly beneficial for pools with fluctuating water chemistry. Its energy-efficient hydraulic design is a plus, as it minimizes the run time required by your circulation pump, potentially leading to lower energy costs over time.

Control-wise, the heater offers a user-friendly front-panel access and an intuitive control pad, making it easy to operate and maintain. This aspect can be particularly advantageous for pool owners who may not be very tech-savvy. Additionally, the unit adheres to low NOx emissions standards, making it an environmentally friendly choice in areas where air quality is a concern.

There are some considerations to keep in mind. Weighing in at 195 pounds and measuring nearly 40 inches in length, this heater may require significant space for installation and might be cumbersome to handle without proper equipment. If you have a larger in-ground pool or spa and prioritize efficiency and durability, the Hayward W3H400FDN is a strong contender in the pool gas heater market, provided you have the space for setup and installation.

The Hayward W3H150FDN Universal H-Series 150,000 BTU Natural Gas Pool and Spa Heater is designed to deliver reliable and efficient heating for in-ground pools and spas. One of its key strengths is the 150,000 BTU rating, which is suitable for medium-sized pools, allowing for quick and effective heating. The efficiency is enhanced by the industry-leading hydraulic design that reduces circulation pump run time, resulting in energy savings.

Another strength is the durable cupro nickel heat exchanger, which offers excellent protection against corrosion, making it a good choice for those with potentially unbalanced water chemistry. This feature contributes to the heater's longevity and reliability. The heater uses natural gas, making it a cost-effective option for those with access to this type of fuel. It also meets low NOx emissions standards, ensuring it has a low environmental impact, which is beneficial for eco-conscious users.

The control features are user-friendly, with front-panel-only access and an intuitive control pad that simplifies operation, service, and maintenance. The Hayward W3H150FDN is a solid option for medium-sized pool and spa owners looking for efficient, durable, and environmentally friendly heating solutions.

The Raypak 266,000 BTU Digital Electronic Ignition Natural Gas Pool Heater is a solid choice for those looking to efficiently heat their swimming pools or spas. Rated at 266,000 BTUs, it offers robust heating power, making it suitable for larger pools. One of its strengths is its efficiency; the intermittent spark ignition ensures the pilot light only activates when needed, which can save on gas usage. It also features a programmable thermostat, adding convenience for users who want to maintain a consistent water temperature.

Durability is another highlight, as the heater is built to withstand various weather conditions. The materials used are designed not to retain residual heat, allowing for installation without expensive heat sinks. This feature can save on initial setup costs and is particularly beneficial for outdoor environments.

There are a few considerations to keep in mind. While the heater's size is manageable, weighing 210 pounds, installation may require professional assistance, especially for those unfamiliar with gas-powered equipment. In terms of gas type, it uses natural gas, which is convenient if you have access to a natural gas supply but may not be suitable for those preferring propane or electric options.