PEN203: Pool Heaters

1. PEN203: INTRO TO POOL HEATERS
Pool & Spa University

2. OVERVIEW
➤ The pool heater is an additional piece of
equipment that can be installed on pools
to provide greater control over the
temperature of the water, which can
extend the swimming season.
➤ Pool heaters are plumbed after the filter
but before any sanitation systems
(chlorine feeders & electrolytic cells).
➤ Many types of heaters are available on the
market and use a variety of fuel sources:
➤ Natural gas
➤ Propane
➤ Electric
➤ Solar
➤ This course looks at gas heater operation.

3. HOW THEY WORK
➤ Heaters are comprised of many
parts, all designed to safely
transmit heat from the unit to
the water.
➤ At its core, the heater exists to
take heat produced in the
firebox and transfer it into the
water through the heat
exchanger, shown at left.
➤ This course will cover the
basics of heater operation and
typical maintenance and
troubleshooting associated
with heaters.

4. HEATER OPERATION
➤ Water flows through a series of headers located at either end of the heat
exchanger. These headers have built-in flow regulators to determine flow into
and out of the system.
➤ Once water passes through the header, it enters the heat exchanger, a series of
several copper thin tubes.
➤ Copper is very good at conducting heat, meaning it will transfer heat quickly
and evenly. This is also why copper cooking pans are highly sought after.
➤ Heat is transferred up from the firebox, which holds several components:
➤ Burner tray
➤ Pilot
➤ Burners
➤ The BTU rating of a heater is directly correlated to the number of burners: a
higher BTU means more burners.

5. INSIDE THE FIREBOX
➤ Once the electrical components of the heater give the OK, the gas valve
inside of the heater opens, allowing gas to flow into the unit.
➤ Once the pilot lights, the heater erectifies, or opens another valve to fire
the main burners.
➤ Heat and gas byproducts then exit through the top of the heater, either
through the heat exchanger (heat) or through the venting at the top of
the heater (byproducts known collectively as flue gas).
➤ One of the byproducts created in this process is carbon monoxide,
an odorless, colorless gas that is deadly. This is one reason why
correct venting is so important and is required for all indoor
installations.
➤ Heaters should only be installed by licensed professional pool
equipment installers!

6. MAINTENANCE & TROUBLESHOOTING
➤ Many heaters today are equipped with diagnostic tools that allow them to
“troubleshoot” themselves, producing error codes that can give some
indication of why the heater may not be functioning properly.
➤ Error codes and their meaning can generally be found in the heater’s
operation manual.
➤ The two most common problems with heaters are bad flow and bad chemistry.
➤ Insufficient flow to the heater will cause it to malfunction. In many cases,
the source of the problem is not in the heater itself, but in the filter. Make
sure the pool filter is cleaned regularly!
➤ Poor water chemistry can degrade the interior of the heat exchanger, either
corroding it away or causing scale formation that prevents the exchanger
from transferring heat into the water. Test water at least weekly and correct
out-of-balance parameters before they lead to a costly equipment repair!

7. CONGRATULATIONS!
You have completed the activity!