Weil-McLain WM97+100 Manual page 97

WM97+ Series 2
Startup — fi nal checks
Throttle screw adjustment
WM97+155 ONLY
DO NOT attempt to adjust the throttle screw unless by a quali-
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.
4. See Figure 105 for location of the
Figure 105 WM97+155
qualifi ed technician, using calibrated combustion test
instruments)
Throttle adjustment screw Throttle adjustment screw
Adjust the throttle screw in small movements.
5. See Figure 92, page 82 . Make sure the Max fi ring rate is set to the
maximum given in the table. If not, adjust 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 reading.
2
a. If the CO is HIGH, turn the throttle screw CLOCKWISE to lower
2
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 COUNTERCLOCKWISE
2
to increase the input. Allow the boiler to stabilize and take another
reading. Continue until the desired CO
6. Lock the boiler into low fi re. Check the combustion 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.
Part number 550-142-204/0117
-
GAS FIRED WATER BOILER
only necessary when specifi ed else-
WM97+155 throttle adjustment screw.
Throttle screw (ONLY for use by a
value is achieved.
2
value is achieved.
2
— Boiler Manual
(continued)
Figure 106
Boiler
Fuel
model
NG
70
LP
NG
110
LP
NG
155
LP
Values above are with the boiler front door
removed. Values will increase about 0.2% once the
door is reinstalled.
REINSTALL
vice.
higher altitudes, CO
slightly higher.
Gas inlet
Low fi re CO
pressure
CO .
test port 2.
❏
Check exchanger and vent seals
1. Operate the boiler on HIGH fi re.
2. Using an inspection mirror, move the mirror
around all heat exchanger joints and vent pipe
connections at the top of the boiler and at the con-
nection to the condensate dish.
3. A leak would appear as vapor on the surface of
the mirror.
4. If there is any indication of a leak at any joint, im-
mediately shut down the boiler.
a. If possible, tighten the retaining screws or nuts
(without over-tightening).
b. If this does not correct the problem, disassemble
the components where the leak appeared. Use
the procedures given in the Maintenance sec-
tion of this manual.
c. When disassembling components, inspect
gaskets to see if there is damage. Replace any
damaged gasket.
d. Contact your Weil-McLain representative if the
problem cannot be addressed with the informa-
tion provided in this manual.
5. Condensate dish joint
a. If the inspection mirror check shows a leak at
the condensate dish-to-heat exchanger joint,
contact your Weil-McLain representative for
instructions to correct the problem.
b. If the mirror test does not reveal a leak at the
condensate dish joint, but there are signs of
weepage or other indications that there might
be leakage, follow the procedure for checking
the heat exchanger-to-condensate dish seal on
page 111.
Acceptable combustion values –
measured values must be within the
ranges given below.
High fi re Low fi re
% CO %
CO ppm CO
2 2
9.25 +/– 1.0 < 150 9.25 +/– 1.0
10.0 +/– 0.5 < 150 10.0 +/– 0.5
9.5 +/– 0.5 < 150 9.00 +/– 0.5
10.5 +/– 0.5 < 150 10.0 +/– 0.5
9.25 +/– 1.0 < 150 8.75 +/– 1.0
10.25 +/– 0.5 < 150 9.75 +/– 0.5
the boiler door after completing ser-
may be slightly lower and CO
2
should be equal to or less than High fi re
2
CO
ppm
< 50
< 50
< 50
< 50
< 50
< 50
– 97 –