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Page 39
KN INSTALLATION AND OPERATION INSTRUCTIONS
Figure 30
Removing boiler jacket top
Figure 31
Gas valve adjustments
Starting the boiler
(continued)
When is low fire adjustment required?
Adjust the gas valve low-fire setting
ONLY
if the flame is unacceptable,
the CO2, O2 or CO are out of acceptable range or you are changing
fuels. You will need to remove the boiler jacket top and adjust the gas
valve low-fire setting as described below.
The boiler jacket top must be removed
when it is necessary to access the gas
valve low-fire adjustment screw or other interior components, such as the blower
motor. Use the procedure below.
Removing the boiler jacket top
1. See Figure 30.
2. Remove the three thumb screws securing the filter access plate.
3. Remove and set aside the filter access cover and gasket.
4. Pull back on the filter clamp and remove the filter.
5. Hold the filter clamp back as in Figure 30.
6. Squeeze the conical grommet sides and maneuver the grommet out of the opening
in the jacket top.
7. If there is no air pipe attached to the air inlet, leave the air inlet plate in place.
8. If air is piped to the air inlet plate, remove the air inlet plate and gasket by removing
the four screws that secure it to the jacket top. Make sure the air piping is properly
supported.
9. Remove the seven Phillips-head screws securing the jacket top to the jacket sides.
10. Lift off the jacket top. (Leave the wire harnesses connected.)
11. Move the insulation aside if necessary.
Adjusting the low-fire setting
DO NOT
adjust the low-fire setting unless low-fire flame or combustion
are unacceptable.
1. See Figure 31 for the location of the gas valve low-fire adjustment. Use a 2-mm
hex wrench.
2. When adjusting the low-fire setting, make changes in half-turn increments. Allow
the flame to stabilize before adjusting each time. (Reduce gas input if the flame or
burner appears red.)
3. If CO
2
is too
HIGH
(O
2
too low):
•
REDUCE
gas by turning the adjustment
COUNTERCLOCKWISE
(one
half turn at a time). Recheck the analyzer and flame after each half turn.
4. If CO
2
is too
LOW
(O
2
too high):
•
INCREASE
gas by turning the adjustment
CLOCKWISE
(one half turn at a
time). Recheck the analyzer and flame after each half turn.
Replace the boiler jacket top
1. To replace the jacket top, reverse this order above. Make sure insulation is in place.
2. Slide the conical grommet over the blower inlet Then seat the grommet ring into
the hole in the jacket top.
3. Reattach the air inlet plate if it was removed. Inspect the air piping to make sure it
was not displaced.
4. Pull the air filter clamp back. Replace the filter, gasket and access cover. Secure with
the three thumbscrews. Replace the gas valve cover plate if removed.
5. Remove the low-fire jumper from the connection board. Replace the electrical
panel cover.
12