Startup — fi nal checks
(continued)
Th rottle screw adjustment
ECO 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 96 .
1. Throttle screw adjustment is
only necessary
when specifi ed
elsewhere in this manual or when combustion tests indicate the
need, as explained under “
❏
Check fl ame & combustion with
instruments
,” page 82.
2. Boiler behavior that might indicate a need to check combustion
values at high fi re (as per page 82 ) 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 4 for location of the
ECO 155
throttle screw.
Gas inlet
pressure
test port
Throttle adjustment screw
Adjust the throttle screw in small movements.
5. See page 73 and Figure 84, page 74 . 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 87, page 76 ) and force the fi ring rate to HIGH (high fi re).
After the boiler has had time to stabilize, take a CO
2
reading.
a. If the CO
2
is HIGH, turn the throttle screw CLOCKWISE to
lower the input. Allow the boiler to stabilize and take another
reading. Continue until the desired CO
2
value is achieved.
b. If the CO
2
is LOW, turn the throttle screw COUNTERCLOCKWISE
to increase the input. Allow the boiler to stabilize and take another
reading. Continue until the desired CO
2
value is achieved.
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.
Figure 95
ECO 155
Throttle screw (ONLY for use by a qualifi ed
technician, using calibrated combustion test
instruments)
Figure 96
Acceptable combustion values —
measured values must be within the
ranges given below
Part number 550-142-190/1218
86
Boiler
model
Fuel
High fi re
Low fi re
%
CO
2
CO
ppm
%
CO
2
CO
ppm
70
NG
9.25 +/– 1.0
< 150
9.25 +/– 1.0
< 50
LP
10.0 +/– 0.5
< 150
10.0 +/– 0.5
< 50
110
NG
9.5 +/– 0.5
< 150
9.0 +/– 0.5
< 50
LP
10.5 +/– 0.5
< 150
10.0 +/– 0.5
< 50
155
NG
9.25 +/– 1.0
< 150
8.75 +/– 1.0
< 50
LP
10.25 +/– 0.5
< 150
9.75 +/– 0.5
< 50
•
Values above are with the boiler jacket door
removed
. Values will increase about 0.2% once the jacket
door is reinstalled.
•
REINSTALL
the boiler jacket door after completing
service.
•
Values above are for altitudes up to 5,500 feet. For higher
altitudes, CO
2
may be slightly lower and CO slightly higher.
•
Low fi re CO
2
should be equal to or less than High fi re CO
2
.
Re-check the Maximum and Minimum CO
2
and
CO rate
1. Turn off the boiler and then turn it back on and put
in Test Mode at maximum. Ensuring the CO
2
setting
level has remained unchanged and confi rm that CO
is within limits.
2. Reduce to minimum and re-check the minimum rate
output ensuring the CO
2
setting level has remained
unchanged and confi rm that CO is within limits.
3. In the event that the CO
2
and CO cannot be obtained,
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.
❏
Check ignition system safety shutoff device
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 fl ow 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 fl ash “Ignition Fault”. It means that the
boiler tried to ignite without success for fi ve (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.
®
S
ERIES
2
G
AS
-
FIRED
WATER
BOILER
—
Boiler Manual
