ATH KN Series, Installation And Operation Instructions Manual

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Cast Iron Condensing Boilers – Installation Manual
Cast Iron Condensing Boilers – Installation Manual
b. Write down the Min Air Shutter Setting! This is
a factory calculated setting. Press the 'Adjust'
button under the Min Air Shutter setting. Using the
arrows, bring Min Air Shutter to (20.0).
c. Give the boiler a call for heat by enabling the
low fire switch on the HeatNet control board to
the low fire position. Switch the Honeywell 7800
flame safeguard control to the "TEST" position,
Figure 18a. This will hold the Honeywell 7800
in the purge state.
d. Take a measurement of the incoming air
temperature and make note of the required low
fire and high fire set point for both percent O2
and CO2. This set point can be found in the
IOM, (Table 11). This reading will be needed
during low and high fire combustion tests
going forward. The air temperature should be
measured as close to the filter box as possible.
e. Switch the Honeywell Flame Safeguard back to
"RUN".
f. Maintain the Min Air Shutter adjustment at
20.0 as the boiler lights and drops to low fire.
In calibrate, when the burner is lit, the boiler
will maintain 40% input for 20 seconds prior to
dropping to low fire. Allow low fire to settle out
for a few minutes.
g. Begin slowly dropping to a Min Air Shutter
setting that is 1 point greater than the factory
set value, using the following routine. (Example:
If the 'Min Air Shutter' factory setting is 9.8, stop
decreasing input at 10.8.)
h. Make a reduction in the Min air Shutter
setting. Move in incrementally smaller steps
while approaching the desired input to
avoid overshoot in zero adjustment. Wait for
combustion to stabilize. Confirm the CO2
is between 7.0%-8.0%. Adjust the low fire
CO2, if necessary, by opening the low fire
adjustment door located on the forward side of
the main gas valve, (Figure 17). A final low fire
combustion adjustment will be done further into
the startup procedure.
i. When finished, select the green check mark.
The boiler will operate in a low fire condition.
20. Switch the Honeywell 7800 back to "run".
21. Create a minimum input demand as before (enable
low fire switch on the HeatNet board). The boiler will
begin the start sequence.
22. Monitor the flame current on the 7800. No flame
current should be detected and the 7800 should
lock out. If flame current is detected at any time
up to the 7800 locking out, the 120V wiring on the
ignition transformer must be reversed and the test
run again to insure that no flame is detected.
Warning Improper wiring of the ignition
transformer can result in an explosion
causing extensive property damage, severe
personal injury or death!
23. Open both manual main shut-off valves and the pilot
gas shut-off valve.
24. Remove the demand from the 7800 control by
disabling the low fire switch allowing the boiler to
stop. Reset the Honeywell 7800.
25. Preliminary Air Shutter and Low Fire Combustion
settings:
a. Enter calibrate screen by placing the calibrate
switch 'S2' in the 'CAL' position, then select the
“Start Calibrate” button on the bottom right
hand side of the calibrate screen.
NOTE: The Calibration Settings represent the mapped
signal sent to the blower and doesn’t reflect the (modulation
%) as indicated on the Master/Member Screens.