Gas Valve Adjustment - Weil-McLain Evergreen 220 User Manual

™ GAS
Startup — final checks

Gas Valve Adjustment

attempt to adjust the throttle or offset screw
unless done by a qualified technician, and with the use of
calibrated combustion test instruments. Adjust the throttle
or offset screw only as needed to meet the combustion val-
ues given in Figure 86. Must confirm correct low fire RPM
before making any adjustments to Offset regulating screw.
1. Throttle screw adjustment is
in this manual or if combustion tests indicate the need, as explained
under "
2. Boiler behavior that might indicate a need to check combustion values
at high fire (as per page 88) 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 fire and low fire.
DO NOT attempt an adjustment of the throttle screw at low fire.
See Figure 85 for location of the throttle screw. Remove the cover
screw to access the throttle adjustment screw.
Adjust the throttle adjustment screw in small movements.
Throttle screw (ONLY for use by a qualified technician,
using calibrated combustion test instruments)
Throttle adjustment screw
Turn counter-clockwise
to increase CO .
2
Turn clockwise to
decrease CO .
2
Make sure the Max firing rate is set to the maximum and confirm the
rpm valve during operation given in the table Figure 93, page 98. If not,
adjust as necessary. Then navigate to DIAGNOSTICS — Manual test
mode (Figure 78, page 79) and force the firing rate to HIGH (maximum
output). After the boiler has had time to stabilize, take a CO
readings.
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. Confirm that the CO is within limits.
Part number 550-100-131/0715
-
FIRED WATER BOILER
if specified elsewhere
Offset Regulating screw
Turn clockwise
to increase CO
Turn counter-clock-
wise to decrease CO
1RWH 0XVW UHPRYH FRYHU
2
value is achieved.
2
value is achieved.
2
— Boiler Manual
(continued)
NG
220
LP
NG
299/300
," page 88.
LP
NG
399
LP
Values will increase about 0.2% once the door is reinstalled.
but must be 0.35% to 0.75% lower than the high fire CO
Low Fire
1. Adjust the boiler to (LOW) (minimum output) and allow the
boiler to stabilize. Confirm the rpm valve during operation
with the table Figure 93, page 98.
2. Remove the slotted cap, see Figure 85, for Offset screw
adjustment.
a. If the CO
2
COUNTERCLOCKWISE to lower the input. Allow the
.
boiler to stabilize and take another reading. Continue until
2
the desired CO
.
b. If the CO is LOW, turn the regulating screw CLOCKWISE
2
2
to increase the input. Allow the boiler to stabilize and take
another reading. Continue until the desired CO
achieved.
c. Confirm that the CO is within limits.
Re-check the Maximum and Minimum
CO and CO rate
2
1. Turn off the boiler and then turn it back on and put in Test
Mode at maximum. Ensuring the CO2 setting level has re-
mained unchanged and confirm that CO is within limits.
2. Reduce to minimum and re-check the minimum rate
output ensuring the CO2 setting level has remained
unchanged and confirm that CO is within limits.
3. In the event that the CO2 and CO cannot be ob-
tained, please contact your Weil-McLain representative.
4. Should you require any assistance during the set up procedure
contact your Weil-McLain representative if the problem cannot
be addressed with the information provided in this manual.
❏
1. After the boiler has been installed, turn off the boiler.
2. Shut off the manual gas valve located on the gas line to stop
and CO flow of fuel to the boiler.
3. Turn on the boiler. It will start the ignition sequence, but will
not light. After some time, the boiler will lockout, the display
screen will turn red, and the Control will flash "Ignition Fault".
It means that the boiler tried to ignite without success for five
(5) times and went into Lockout mode. This means that the
ignition system safety device worked properly.
4. Clear the Lockout condition by selecting "Manual Reset" in
the Diagnostic Menu.
5. Open the manual gas valve located on the gas line to resume
fuel supply to the boiler.
Acceptable combustion values —
measured values must be within the ranges
given below
% CO
CO ppm
2
9.25 ± 0.5 < 100 8.75 ± 0.5
10.75 ± 0.5 < 120 10.25 ± 0.5
9.25 ± 0.5 < 100 8.75 ± 0.5
10.75 ± 0.5 < 120 10.25 ± 0.5
9.25 ± 0.5 < 100 8.75 ± 0.5
10.75 ± 0.5 < 120 10.25 ± 0.5
the boiler door after completing service.
listed is typical. The valve may vary with conditions,
2
is HIGH, turn the offset regulating screw
value is achieved.
2
% CO
CO ppm
2
< 50
< 50
< 50
< 50
< 50
< 50
.
value.
2
value is
2
– 89 –