I pg 10
Section 3. Installation
SEQUENCE OF OPERATION
An electronic temperature sensing
thermistor
in the manifold adapter inlet controls the heater
operation. When the inlet water temperature drops below the temperature set on the
operating
control,
the
burner controller
supplies power to the combustion
air blower
through a series
of
safety interlocks.
The interlocks consist of:
• the
pressure switch (PS),
which senses that the pump is running,
• the
high limit switch (HLS),
which opens if the heat exchanger outlet temperature goes
above 53° C (127° F), and
• the
air flow switch (AFS),
which senses the pressure drop across the air metering orifice,
• the
automatic gas shut-off (AGS)
switch, which opens if the heat exchanger outlet
temperature goes above 60° C (140° F).
• the
stack flue sensor (SFS),
which shuts down the heater if the flue gas temperature
reaches 249° C (480° F).
• the
high limit switch (HLS), which opens if the heat exchanger outlet temperature
goes above 55° C (131° F), and....
• the
inlet temperature control switch, which opens if the inlet temperature goes above
45° C (110° F).
The air flow switch (AFS) senses the pressure drop across the air metering orifice. As soon as
there is sufficient air flow, the AFS closes, closing the circuit to the
hot surface igniter (HSI),
which ignites the fuel mixture. On a call for heat, the blower and HSI are energized. In about 20
seconds, the gas valve opens and ignition occurs. The HSI then switches to a sensing mode
and monitors the flame.
The heater is equipped with a digital operating control that enables the user to pre-set the
desired pool and spa water temperatures. The control enables the user to select between pool
and spa heating, and features a digital display that indicates the water temperature.
PUTTING THE HEATER INTO SERVICE
If the heater is installed below the level of the pool, or more than 0.6 meters (2 feet) above
pool level, the pressure switch setting should be adjusted. See “WATER PRESSURE SWITCH”
in the “SAFETY CONTROLS Section” (page 32) and the “CAUTION” under “BELOW POOL
INSTALLATION Section” (page 12).
Before putting the heater into service for the first time, follow the instructions under “BEFORE
START-UP” (page 30) in the front of this manual. Check for proper operation of the heater by
following the steps under “OPERATION INSTRUCTIONS.”
Damage to equipment caused by improper installation or repair will void the warranty.