Weil-McLain Evergreen EVG 70 Manual page 98

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g
Startup — fi nal checks
Th rottle screw adjustment
EVG 155 ONLY
DO NOT attempt to adjust the throttle screw unless by
a qualifi 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 86 .
1. Throttle screw adjustment is
elsewhere in this manual or when combustion tests indicate the
need, as explained under "❏ Check fl ame & combustion with
instruments," page 94.
2. Boiler behavior that might indicate a need to check combustion
values at high fi re (as per page 94 ) to verify boiler is in adjustment
include: difficulty igniting, poor flame stability at low fire,
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 85 for location of the
Figure 85 EVG 155
Throttle screw (ONLY for use by a qualifi ed
technician, using calibrated combustion test
instruments)
Throttle adjustment screw
Adjust the throttle screw in small movements.
5. Make sure the Max fi ring rate is set to the maximum and confi rm the
RPM value during operation given in Figure 90, page 105 . If not, adjust
as necessary. Then navigate to DIAGNOSTICS — Manual test mode
(see Figure 76, page 85 ) and force the fi ring rate to HIGH (high fi re).
After the boiler has had time to stabilize, take a CO
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
c. Confi rm that the CO is within limits.
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.
98
as-fired water boiler —
when specifi ed
only necessary
throttle screw.
EVG 155
2
value is achieved.
2
value is achieved.
2
70/110/155
(continued)
Figure 86 Acceptable combustion values —
Boiler
model Fuel
EVG
70
110
155
• Values above are with the boiler jacket door
removed. Values will increase about 0.2% once the jacket
door is reinstalled.
REINSTALL
•
service.
• Values above are for altitudes up to 5,500 feet. For higher
altitudes, CO
• Low fi re CO
Gas inlet
❏
pressure
Chec k Heat exchanger and vent seals
test port
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 connection 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,
immediately 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 section of
this manual.
c. When disassembling components, inspect gaskets
to see if there is damage. Replace any damaged
gasket.
reading.
d. Contact your Weil-McLain representative if the
problem cannot be addressed with the information
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.
Boiler Manual
measured values must be within the
ranges given below
High fi re
% CO
CO ppm
2
NG 9.25 +/– 1.0 < 150 9.25 +/– 1.0
LP 10.0 +/– 0.5 < 150 10.0 +/– 0.5
NG 9.5 +/– 0.5 < 150
LP 10.5 +/– 0.5 < 150 10.0 +/– 0.5
NG 9.25 +/– 1.0 < 150 8.75 +/– 1.0
LP 10.25 +/– 0.5 < 150 9.75 +/– 0.5
the boiler jacket door after completing
may be slightly lower and CO slightly higher.
2
should be equal to or less than High fi re CO
2
Part number 550-100-191/0917
Low fi re
% CO
CO ppm
2
< 50
< 50
9.0 +/– 0.5 < 50
< 50
< 50
< 50
.
2