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second and the pilot spark ignition is initiated until
the pilot flame has been reestablished. This sequence
should be checked by turning off the manual pilot
gas valve (see Figure 14), and, at the same time,
monitoring the audible sparking at the pilot burner and
signal interruption to the main valve.
Caution
Propane gas is heavier than air and sinks to
the ground. Exercise extreme care in lighting
the heater when so equipped.
System 16
- (electronically supervised standing
pilot system). Extinguish the pilot flame by placing
the manual pilot valve in the closed positions (see
Figure 14), and at the same time, begin recording the
time it takes for the output signal from the electronic
ignition control to be interrupted. The signal interruption
can be detected either with a test light or a voltmeter.
The response time should never exceed one second.
2. Hi-Limit Checkout. For spas see Section 3.9.
The manual reset high limit is factory preset to
150°F (66°C). Confirm this set point on the unit
and adjust if necessary. After running the heater
in a firing mode for 10 minutes, slowly close the
outlet valve “A” to raise the outlet temperature
as indicated on the outlet thermometer. The high
limit should trip within 2°F (1°C) or 3°F (2°C)
of the 150°F (66°C) setpoint and shut off the
burners. If this does not occur, adjust the set point
on the unit to shut off the burners when the outlet
thermometer reads 150°F (66°C). Open the outlet
valve “B” and push the reset button. The main
burners should reignite.
3. Flow Switch: See attached vendor literature.
4. Low Water Cutoff (optional): See attached vendor
literature.
3.4 Inlet Temperature and Temperature
Rise Adjustment
For proper operation the bypass and outlet valves
must be adjusted to obtain the correct heater
temperature rise. Use the following method to set
the bypass assembly at start up:
1. With all bypass valves open, fire the heater for at
least 10 minutes. The operating control should
be set at least 5° to 10° F (2° to 5°C) above the
pool temperature to ensure continued operation
throughout this set up procedure.
2. Observe the thermometer on the inlet header. To
prevent condensation and damage to the heater, the
inlet water temperature has to be 110°F (43°C).
If the inlet temperature is LESS THAN 110°F
(43°C):
With the bypass valve “A” fully open,
throttle (turn down) outlet valve “B” slightly.
Observe the inlet thermometer for 5 minutes to see
where the inlet temperature stabilizes. If it remains
under 110°F (43°C), throttle outlet valve “B” a little
more. Repeat as necessary. If the inlet temperature
rises above 110°F (43°C), open outlet valve “B”
slightly until the inlet temperature stabilizes as close
to 110°F as possible (plus or minus 2°F (1°C)).
If the inlet temperature is MORE THAN
110°F (43°C).
If outlet valve “B” has been throttled
partially closed, open it slightly, wait 5 minutes, and,
if the temperature is not down to 110°F (43°C) (plus
or minus 2°F (1°C)) open it some more. If bypass
valve “B” is fully open and you are still seeing inlet
water temperatures in excess of 110°F (43°C), you
can adjust bypass valve “A”. Throttle it (turn down)
slightly towards closed, and wait until the inlet water
temperature stabilizes again. Repeat as necessary.
When the inlet temperature is stabilized at 110°F
(43°C), either lock the valve handles, remove
them, or prominently mark them to prevent
tampering or accidental changes to the valve
positions.
If the pool water temperature needs to
be raised more than 10° F (5°C) to reach
a comfortable swimming temperature,
inspect and re-adjust the valves twice a day
to maintain the 110°F (43°C) inlet water
temperature.
3. To prevent nuisance high limit tripping, set the
adjustable pump time delay relay to 10 minutes
for all models. This allows the heater pump to
circulate water through the heat exchanger after
the burners shut off, recovering all residual heat in
the metal components.
4. The heater outlet temperature with the bypass
adjusted as detailed above should be less
than 142°F (61°C). The normal range will be
10 to 37°F (5° to 18°C) higher than the inlet
temperature. If it exceeds 142°F (61°C), please
contact the Service Department at 800-900-9276
for instructions. Outlet temperatures in excess of
142°F (61°C) may cause intermittent high limit
tripping.
POOL OPERATING CONTROL ADJUSTMENT:
5. Adjustable Differential Feature: Remove the cover
from the control box and verify that the white
differential potentiometer is set at about 2°F
(1°C). NOTE: a 2°F
(1°C) differential means that,
if the thermostat is set at 80°F (27°C), the heater
will come on at 78°F (25°C) and go off when the
pool reaches 80°F (27°C). The 2°F (1°C) value is
a good starting point for most installations. This
differential may be adjusted up or down to suit
individual applications.
6. The operating control temperature setting can be
MightyTherm Pool Heater
