The advantages and disadvantages of gas pool heaters plus the circumstances when they are the best option.

1. Are Gas Pool Heaters A Good Buy?
Although lots of gas pool heaters are sold they are not as energy efficient as alternatives
like heat pumps or solar heating systems so buying one might be considered
environmentally unfriendly.
Against this we have to accept that lots of this type of pool heater are sold because they
have advantages over the competition:
• Relatively cheap to buy and install - Obviously the cost depends on the size of
your pool but gas pool heaters for above ground pools are available under $1000
and for in-ground pools under $1500. You will have to pay to have the gas and
electric side of things professionally installed but the rest of the installation should
be within the capability of someone who is reasonably handy.
• Powerful - One major benefit of gas pool heaters is that they have a high capacity
(up to 400k BTU/hr for residential pools) and can therefore heat the water
relatively quickly. This makes them the best option if you only heat your pool
occasionally.
• Energy Efficiency - Gas pool heaters are much more efficient that they used to be
with most falling in the 80-85% range. The top rating for a gas pool heater is
presently 95% but whilst this saves on running costs you have to pay more for
such an efficient heater.
• Reliability - Whilst gas heaters are constantly being improved the basic
technology is well understood and tested. A properly maintained heater should
give you many years of worry free pool heating.
• Independent of the weather - A gas pool heater will operate in all weather
conditions.
Ideally gas pool heaters should use natural gas but most ranges include versions for use
with propane. In terms of performance it does not matter which you use but in terms of
cost there is a major difference. Propane can cost up to twice as much as natural gas so is
never the preferred option.
Gas pool heaters are available in both electronic and millivolt versions. Electronic heaters
are the most popular as they feature efficient electronic ignition and sophisticated digital
controls. Of course these systems rely on an electrical connection. If providing an
electrical connection is a problem then the answer is a millivolt heater. These use a pilot
light (which wastes some gas) and have simple controls but do not need electricity.
Many manufacturers offer models with many different versions of heaters, major players
in the market include Raypak, Zodiac/Jandy and Hayward Pool Products.
The main competition these days comes from pool heat pumps. These are considerably
more expensive to buy and are not as powerful. They work on electricity which is more
expensive than gas and they don't operate at low temperatures. Their big advantage is that

2. they move heat from the air to the water rather than generating it. This gives them an
energy efficiency rating of several hundred percent and makes them cheap to run.
If you heat your pool constantly during the season then you should certainly consider a
heat pump. If you don't heat your pool constantly you will probably find that, taking into
account up-front costs, running costs and heating power, a gas pool heater is the best
option.