Time Clock/Fireman's Switch
To operate the heater with a time clock, connect the timer
to the fireman's switch connection in the heater's wiring.
The time clock should be of the dual switch type and set to
shut off the call for heat to the pool heater 15 to 20 minutes
prior to shutting down the pool pump. The fireman's switch
connection is located on the 6-pin header connected to the
digital control board. Splice into the red wire jumper tagged
"Where necessary add "Fireman's" switch circuit here" to
connect the time clock. The fireman's switch connection
must be a dry contact and must not supply power to the
heater. Powering the fireman's switch connection externally
may damage the heater, and is not covered by warranty.
Do not exceed 50' (15.2 m) of total wiring using 18 AWG
stranded copper wire rated for 105°C (221°F) minimum.
NOTE: When using a time clock, the heater will display
"Clock/ Fireman Sw" when the fireman's switch is open,
indicating that the time clock has shut off the call for heat.
High Limits
The heater is equipped with two automatic high limits. Both
are located in the inlet/outlet header. Both are set to open
at 135°F (57°C).
NOTE: An erratic high limit is often characteristic of
an internal heat exchanger problem, e.g. scale build-up,
defective bypass. Refer to "TROUBLESHOOTING" on
page 41).
High Limit Removal
1. Shut off main electrical power switch to heater.
2. Remove front door.
3. Remove defective high limit and replace with a new
high limit.
4. Replace inspection panel.
Figure 38. High Limit
Flow Switch
This standard, dual-purpose control, mounted and wired in
series with the main gas valve, shuts off heater in case of
pump failure or low water flow.
Figure 39. Flow Switch
Blocked Vent Switch
This heater is equipped with a blocked vent pressure
switch to prevent the operation of the heater when the vent
is blocked.
BLOCKED VENT SWITCH
0.75" WC
Figure 40. Blocked Vent Switch
Adjusting Valve Manifold Pressure
1. Gas manifold pressure is measured at the pressure
tap between the gas valve and gas orifice (See
Figure 42).
2. To increase the manifold pressure and increase
the ratio of fuel to air turn the adjustment screw
counterclockwise (toward the +) (See Figure 41
For example, a reading of -2.0" WC (-0.5 kPa) can
be increased to -1.5" WC (-0.4 kPa) by turning the
adjustment
screw
manifold pressure will increase the CO2 percentage
in the flue gases.
3. To decrease the manifold pressure and decrease the
ratio of fuel to air turn the adjustment screw clockwise
(toward the -) (See Figure 41). Decreasing manifold
pressure will reduce the CO2 percentage in the flue
gases.
NOTE: Manifold pressure will decrease when the intake
air filter becomes dirty. Replace the filter when manifold
pressure drops to less than -2.5" WC or intake suction
pressure is less than -1.0" WC.
counterclockwise.
Increasing
35