A look at the pool heaters available from this well known manufacturer. For more information please visit http://poolheatersreviewed.com.

1. Hayward Pool Heaters
Hayward pool heaters are manufactured by Hayward Pool Products, a
division of Hayward Industries, Inc., who have been manufacturing pool
equipment for over 80 years. They have become one of the largest
manufacturers of pool products and their catalogue includes filters,
pumps, automatic cleaners, lights and, of course, pool heaters. The fact
that they have been around so long shows that pool owners like their
products.
Their range of pool heaters is as follows:
High powered heaters for in-ground pools
The Universal H Series - A series of gas powered pool heaters using either
propane or natural gas. Power levels range from 150K to 400K BTU/hr.
The key benefit of these heaters is that they are energy efficient (84%)
and produce emissions of NOx low enough to meet the most demanding
local requirements including those of California and Texas. The Universal
H Series heaters have electronic ignition and are controlled via a digital
LED control panel. They are designed for easy installation, for example the
connections can be made left or right.
H Series Millivolt - Again a range of heaters powered by either natural gas
or propane. The available power levels range from 150 - 250k BTU/hr with
the Hayward H250 being the most popular. Their energy efficiency is 81%
and there is no claim as to low NOx. Ignition is via a standing pilot light
which is also used to produce a tiny volume of electricity to support the
heater. The advantage of millivolt heaters is that there is no need for an
electrical connection so they are more flexible as regards location.
Which is the best choice? - The Universal H Series would be the best
choice except in the situation where connecting the heater to an electricity
supply is difficult. In this case the H Series Millivolt provides a good
alternative.
Hayward above ground pool heaters
Above Ground H Series - Here we have a 100k BTU gas heater (no other
power level options) for use with either propane or natural gas. Electronic
ignition is powered by a standard plugin electrical connection. Energy
efficiency is 81%. Induced draft system means the heater is not affected
by wind so it can be located where it is needed.
Hayward Heat Pump - A range of heat pumps from 50 - 125 BTU/hr. The
advantage of a heat pump is that, rather than generate heat, it "pumps"
heat from the surrounding air into the water. This results in very high
energy efficiency and makes heat pumps environmentally friendly. As a
result the energy output (heat) is greater than the energy input
(electricity - 30amp supply required). Heat pumps are therefore much
cheaper to run than a gas heater, however, they cost considerably more
to buy. The 50k BTU version can heat a pool up to 13,000 gallons.

2. Which to choose - This is not as easy a decision as with in-ground pools..
The heat pump is cheaper to run but costs more to buy. If you buy the
recommended model for your pool size a gas heater will provide faster
heating. If you are going to heat the pool constantly during the season
then a heat pump will be best. On the other hand if you only heat it
occasionally it will be best to go for a gas heater.
Generally you are well advised to go for a higher capacity heater than you
need. If you match you requirements correctly any of the Hayward pool
heaters will provide years of good service.