Swimming Pool Heaters – Why the Pool Gas Heater Is Most Popular

Start-Up Cost

The initial costs involved with a gas pool heater are surprisingly low. The cost of the unit itself varies a great deal but is determined mainly by the size of your swimming pool. A larger pool will require a larger heater. Naturally, an outdoor pool in Alaska is going to take a little more heating effort than the same pool in Phoenix! A larger heater will raise the pool temperature faster but once you are at your most comfortable temperature it does not take as much effort to maintain it.

The actual purchase cost of a gas pool heater should be somewhere between about $1,000 and $3,000 plus about $150 to $850 for professional installation. Can you install it yourself? Yes, apart from any electrical or gas connections, the rest of the installation should be fairly straightforward for any handyperson with some basic tools. Some PVC pipe modifications are all that is needed to insert the heater between your existing pool filter and the pool. Basic instructions which will give you an idea of the task can be found at the bottom of this article so you can decide if your aptitude is up to it.

Running Cost

There are two options when it comes to the supply of gas for your pool heater. The heater you buy is dependent on the type of gas you will be using so it is quite important. If you have gas piped to your house, this is Natural gas (or town gas) and is the cheaper option. Otherwise you will be using bottled gas which is Propane and more expensive. Propane will be up to double the cost of natural gas. Using a pool cover will cut the heating cost down by about 80% and this applies with ANY heating system. The one point which cannot be stressed enough is INVEST IN A POOL COVER.

A second running cost which is often overlooked is the cost of maintenance. Gas pool heaters are not too bad but there is still going to be some scale build-up and possibly damage from chemical imbalances. Heat exchangers are a lot better than they were as technology improves but an out-of-balance pool can still cause damage. An annual service could be good preventive measure – you will usually find a maintenance schedule in the user manual supplied with the heater. A well-maintained gas pool heater should last 5 to 10 years.


Modern gas pool heaters can run at up to around 95% efficiency. That is to say, for every $100 you spend in gas you get $95 worth of heat into your pool water. Not too long ago most gas pool heaters were around the 50% mark so there have been considerable improvements over the years. This efficiency may seem low compared to the efficiency of a heat pump pool heater at around 400% to 500% but there are other reasons for using gas heaters rather than heat pumps. For example, heat pumps stop working around 45 degrees F and below and have a shorter lifespan. Technological advances in heat exchangers used in gas heaters have made them more efficient and longer lasting.


One of the great things about a gas heater is their simplicity. There is not an awful lot in the way of electronics and other wizardry built into them. Because there is less to go wrong they tend to run for long periods problem-free as opposed to heat pumps which can be prone to faults simply due to there being more to go wrong. In very basic terms, all you have is a gas burner and a heat exchanger with a temperature control to regulate the gas flow – less electronics equals less problems.


Gas heaters are at their most efficient when heating a pool from a low temperature which makes them ideal for people who want to use a pool on an occasional basis. For example, you could raise the temperature of a 30,000 gallon pool by about 20 degrees F within 24 hours using a gas pool heater with an output of around 400,000 BTU. Maintaining a temperature once achieved requires a lot less output – particularly if you use a pool cover.

In summary, gas pool heaters are a very good all-round way to increase the temperature of your swimming pool. They will increase the temperature quickly on demand and will operate at temperatures below freezing. They are simple and have quite a decent life expectancy when properly maintained. They are reasonably cost-effective both to initially purchase and to run when combined with the use of a pool cover. With the right advice on selection, a gas swimming pool heater will give you a long and satisfying swimming season without a major dent in your bank balance.