Weil-McLain Ultra Manual page 75

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gas fired water boiler
Startup — final checks
7. Measure natural gas input:
a. Operate boiler 10 minutes.
b. Turn off other appliances.
c. At natural gas meter, measure time (in seconds) required to
use one cubic foot of gas.
d. Calculate gas input:
e. Btuh calculated should approximate input rating on boiler
rating label.
8. Use the U-Control display to navigate to Manual test mode (see
Figure 85, page 64) and force the firing rate to MIN (low fire).
9. Look at the flame through the flame inspection window. The low
fire flame should be stable and evenly distributed over burner
surface with a uniform orange color.
10. Repeat the combustion test of steps 4 and 5 above.
11. Use the U-Control display to navigate to Manual test mode (see
Figure 85, page 64) and force the firing rate to AUTO (normal
operation).
12. Replace the flue gas temperature sensor.
You must replace the flue gas temperature sensor to
prevent flue gas spillage into the boiler enclosure. Failure
to comply could result in severe personal injury, death
or substantial property damage.
Throttle screw adjustment procedure
DO NOT attempt to adjust the throttle screw unless by
a qualified technician, and with the use of calibrated
combustion test instruments. Adjust the throttle screw
only as needed to meet the combustion values given in
Figure 88.
1. This procedure is only necessary when combustion tests indicate
the need, as explained under "❏ Check flame & combustion
with instruments, page 74."
2. Boiler behavior that might indicate a need to check combustion
values at high fire (as per page 74) to verify boiler is in adjustment
include: difficulty igniting, poor flame stability at low fire, combus-
tion noise or high carbon monoxide values.
3. Combustion readings must be taken at both high fire and low fire.
DO NOT attempt an adjustment of the throttle screw at low fire.
Just check the combustion values.
4. Use the U-Control display to navigate to Manual test mode (see
Figure 85, page 64) and force the firing rate to MAX (high fire).
After the boiler has had time to stabilize, take a CO
a. If the CO is HIGH, turn the throttle screw CLOCKWISE to
2
lower the input. Allow the boiler to stabilize and take another
reading. Continue until the desired CO
b. If the CO is LOW, turn the throttle screw COUNTERCLOCK-
2
WISE to increase the input. Allow the boiler to stabilize and
take another reading. Continue until the desired CO
achieved.
5. Lock the boiler into low fire. Check the combustion readings. If
results are acceptable at low fire, verify high fire readings again.
Restore firing rate to AUTO.
Part number 550-100-066/0608
— Boiler Manual
(continued)
Figure 89
reading.
2
value is achieved.
6.
2
value is
2
❏
1.
Throttle screw location (ONLY for
use by a qualified technician, using
calibrated combustion test instruments)
Consult your local Weil-McLain representative if ac-
ceptable results cannot be obtained for both high and
low fire.
Adjust and test boiler controls
Follow instructions in this manual to set and verify
operation of the boiler controls.
75