Generally, depending on where you live, running a natural gas pool heater can cost around $300 per month, while propane can cost up to $1000. A 100,000 BTU unit will probably use one therm per hour, while a 400,000 BTU unit will use four therms per hour. Natural gas typically costs around $0.90 per therm, while propane costs twice as much in some cases.
So, as you can see, knowing how much a gas pool heater will cost depends on many variables, the most significant of which will be the pool size, fuel source, heater size, and ambient temperature.
To calculate the costs of a gas pool heater, we’ll start with estimating the most prominent variables.
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Type Of Pool Heater

When selecting a pool heater, there are several factors to consider, including the size and the type of energy used. The energy source may include solar, electric, propane, or heat pump systems. The price of a pool heater includes both the initial purchase cost of the unit and its running costs.
Electricity and propane are generally more cost-effective in certain areas, but gas heaters can be more expensive. Ultimately, the cost of running a pool heater will depend on the homeowner’s needs.
Size Of The Pool
The next thing you need to consider is the size of the pool. A large-size pool will require more energy to heat up compared to a medium or small-size pool. That means it will consume more gas and be more expensive to operate.
However, you will also need to purchase a large-size pool heater for a large pool, which can be significantly more expensive upfront. Installation costs of a small versus large pool heater, on the other hand, don’t differ a great deal.
Fuel Source
Gas pool heaters are a popular choice among homeowners. These heaters can run on a propane tank or a natural gas line. Choosing a natural gas heater will cut heating costs in half compared to electric heaters.
Propane heaters will cost more per month but are still an excellent choice if you don’t have a natural gas line on your property. Depending on where you live, gas prices may be lower than you expect or more expensive. So, do the math ahead of buying a gas pool heater.
Size Of Heater
The size of gas pool heaters can vary widely, depending on their BTU per hour of output. Typically, the larger the BTU, the more expensive they are. Raypak, a popular brand, sells natural gas pool heaters for around $2,500. More expensive models can cost up to $3,400.
Operating Costs
The installation of a gas pool heater can cost between $500 and $1500.You can expect to pay an additional $100 to $200 per month for operating the heater.
Remember that the actual heating cost will depend on the weather and outside temperature. For example, if the water is cold, which it will be during the winter, the heater will need to run harder and consume more gas, thus making it more expensive to operate than in the summer months when the water is warmer.
Installing A New Heater
The cost of installing a gas pool heater can vary widely. While professional installation services are highly recommended, you may be tempted to try and do it yourself. However, the incorrect installation of a gas pool heater can cause it to malfunction prematurely, and it can even void its warranty. Proper installation involves routing utility lines and electrical wiring and venting sometimes, so it’s pretty technical stuff.
Although using high-quality materials and labor can be expensive during installation, it will help save you money in the long term.
Using A Solar Blanket To Reduce Operational Costs
Pool owners can use a solar blanket to reduce the operational costs of a gas pool heater. A solar blanket is a cover for your swimming pool, which helps retain the warmth in the water by reducing evaporation.
Clear covers can increase the temperature of the water by up to 15 degrees, and they prevent 95% of the water from evaporating. Dark blue solar covers are also very effective at heat retention, which will help reduce the running time of the pool heater and save you money.
Final Word
As we’ve discussed, quite a few variables factor into what a gas pool heater can cost you. While you can control most variables, other variables like gas and propane prices aren’t in your control, so it’s best to do your research well in advance of making a decision.
The best approach is to do the math to determine if a gas pool heater is a better option than an electric heater for your specific situation. Depending on where you live and the price of gas, one may offer you better savings than the other.