Weil-McLain WM97+100 Manual page 96

WM97+ Series 2
Startup — fi nal checks
Throttle screw adjustment
WM97+110 ONLY
attempt to adjust the throttle screw unless by a quali-
DO NOT
fi ed 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 106 .
1. Throttle screw adjustment is
where in this manual or when combustion tests indicate the need, as
explained under "❏ Check fl ame & combustion with instru-
ments," page 93 .
2. Boiler behavior that might indicate a need to check combustion values
at high fi re (as per page 93 ) to verify boiler is in adjustment include:
diffi culty igniting, poor fl ame stability at low fi re, combustion noise
or high carbon monoxide values.
3. Combustion readings must be taken at both high fi re and low fi re. DO
NOT attempt an adjustment of the throttle screw at low fi re. Just check
the combustion values.
Figure 104 WM97 +110
qualifi ed technician, using calibrated combustion test
instruments)
Throttle adjustment screw
Gas inlet pressure test port
– 96 –
-
GAS FIRED WATER BOILER
when specifi ed else-
only necessary
Throttle screw (ONLY for use by a
— Boiler Manual
(continued)
4. See Figure 104 for location of the
throttle adjustment screw.
5. See Figure 92, page 82 . Make sure the Max fi ring rate
is set to the maximum given in the table. If not, ad-
just as necessary. Then navigate to DIAGNOSTICS
— Manual test mode (see Figure 96, page 86 ) and
force the fi ring rate to MAX (high fi re). After the
boiler has had time to stabilize, take a CO
a. If the CO
CLOCKWISE to lower the input. Allow the
boiler to stabilize and take another read-
ing. Continue until the desired CO
achieved.
b. If the CO
COUNTERCLOCKWISE to increase the input.
Allow the boiler to stabilize and take another
reading. Continue until the desired CO
is achieved.
6. Lock the boiler into low fi re. Check the combus-
tion readings. If results are acceptable at low fi re,
verify high fi re readings again. Restore fi ring rate to
AUTO. DO NOT adjust throttle on low fi re.
7. Consult your local Weil-McLain representative
if acceptable results cannot be obtained for both
high and low fi re.
WM97+110
Adjust the throttle screw in small move-
ments.
is HIGH, turn the throttle screw
2
is LOW, turn the throttle screw
2
Part number 550-142-204/0117
reading.
2
value is
2
value
2