Weil-McLain Evergreen 220 LP Service manual

Weil-McLain Technical Bulletin
TB1601 - February 15, 2016
Evergreen Liquid Propane Conversion – Gas Valve Adjustment
Hazard Definitions:
The following defined terms are used throughout this manual to bring attention to the presence of hazards of
various risk levels or to important information concerning the life of the product.
Indicates presence of hazards that
will cause severe personal injury,
death or substantial property
damage.
Indicates presence of hazards that
can cause severe personal injury,
death or substantial property damage.
The use of a properly working, calibrated
flue gas analyzer is required to convert this
unit and determine proper gas valve
settings. Do not perform this conversion
without a flue gas analyzer. Improper gas
valve settings can cause severe personal
injury, death or property damage.
Do NOT fire the Evergreen™ boiler after the
Liquid Propane conversion without utilizing a
properly working, calibrated combustion
analyzer to adjust the gas valve to the
proper settings after the initial light off. Do
NOT allow the boiler to modulate freely until
the combustion analysis and adjustment is
complete. Failure to do so may result in a
loud ignition that may cause burner/boiler
damage. Please refer to the Evergreen LP
conversion instructions for the proper LP
conversion procedure. Failure to follow all
directions may cause boiler damage and
could result in severe personal injury, death
or substantial property damage.
This technical bulletin describes the proper initial, coarse
adjustment of the Evergreen gas valve for LP operation.
This adjustment must be made prior to initially lighting the
LP gas boiler. Refer to the boiler manual for instructions
and figures related to gas valve adjustment. Figure 1 is
included in this bulletin as a reference of throttle and
offset locations.
Prior to the boiler’s first ignition, adjust the throttle
adjustment screw by first turning the screw clockwise until
it bottoms out – do not apply any torque. Adjust the
throttle screw in a counterclockwise direction with
precisely the number of turns listed in Table 1, according
to the boiler model/size.
After the throttle has been adjusted coarsely, the offset
regulating screw must be adjusted. Remove the sealed,
slotted cap protecting the white offset regulating screw
before making adjustments. It is critical to be precise for
the adjustment of the offset regulating screw.
Figure 1 Gas valve adjustment locations—ONLY for use
by a qualified technician, using properly
working, calibrated combustion test
instruments.
Do NOT attempt to bottom out the offset regulating
screw as was done for the throttle adjustment.
Adjustments to the offset regulating screw should be
made from the factory-provided natural gas position.
Adjust the offset regulating screw using the following
steps, referencing Figure 2:
1. Use a marker to mark the corner of one tip of the
cross on the offset regulating screw and the
corresponding location on the outside of the screw
housing, as shown in Figure 2a.
2. Turn the offset regulating screw 1/4 turn
counterclockwise, ensuring that the tip of the cross
aligns with the mark on the outside of the screw
housing, as shown in Figure 2b.
Figure 2 Offset regulating screw adjustment—(a)
Marking factory-provided NG position. (b) View
after 1/4 turn CCW adjustment.
a) b)

Table 1: Course adjustment settings—Throttle and offset
adjustments to be made prior to first ignition, by
size.
Boiler
Model
Throttle Turns
(Counterclockwise
fromBottom-out
Position)
Offset Turns
(Counterclockwise
from Factory NG
Position)
220 LP
3/4
1/4
299 LP
1-3/8
1/4
399 LP
1-5/8
1/4
Before firing, verify that the “Max Rate” for the input
(priority) used to fire the boiler is set between 96% and
100%. Also verify that the ‘Min Rate” is set to 10% or the
minimum rate allowed (if above 2000 ft. elevation).
Adjust control settings if not at proper rate. Verify that
boiler is operating at the expected firing rate at both
high- and low-fire during combustion analysis. Refer to
Table 2 for proper low-fire rate based on altitude settings.
During combustion analysis, ensure boiler is
operating at the expected firing rate. Failure
to operate boiler at proper rate during
combustion testing and adjustment could
result in incorrect combustion settings.
Improper gas valve settings can cause
severe personal injury, death or property
damage.
Table 2: Low-fire blower speeds—Minimum blower
speed settings according to altitude settings.
Altitude
Setting (ft.)
Lowest Rate for Altitude
220
299
399
0-2000
10%
10%
10%
2500
11%
11%
12%
3000
12%
11%
12%
3500
12%
11%
12%
4000
12%
12%
13%
4500
13%
12%
13%
5000
13%
12%
13%
5500
13%
13%
14%
6000
14%
13%
14%
6500
14%
13%
14%
7000
14%
14%
15%
7500
15%
14%
15%
8000
15%
14%
16%
8500
15%
14%
16%
9000
16%
15%
16%
9500
16%
15%
17%
10000
17%
15%
17%
10500
17%
16%
17%
11000
17%
16%
18%
Review the procedure and control sequence for the
operation of the Manual Test Mode in the section of the
boiler manual “Manual Test Mode for Single and Multiple
Boilers”. The procedure differs between boilers set as a
single or multiple-boiler unit.
Do NOT allow the boiler to modulate freely until the
combustion analysis and adjustment is complete. Fire
the boiler and force it to High Fire in Manual Test Mode.
Adjust the high fire combustion first, using the throttle
adjustment screw, to the specification in the boiler
manual, reproduced in Table 3. Then, force the boiler to
low fire and adjust the offset regulating screw to the
specification in the boiler manual, reproduced in Table 3.
Follow the full startup instructions found in the Evergreen
Boiler Manual.
Table 3: Acceptable combustion values—measured
values must be within the ranges given below.
Boiler
Model
High Fire
Low Fire
% CO2
CO
ppm
% CO2
CO ppm
220 LP
10.75 ±0.50
< 120
10.25 ±0.50
< 50
299 LP
10.75 ±0.50
< 120
10.25 ±0.50
< 50
399 LP
10.75 ±0.50
< 120
10.25 ±0.50
< 50
To clarify, both the high fire and low fire gas adjustment
MUST be made with a properly working, calibrated
combustion analyzer according to the instructions in the
boiler manual to ensure safe, reliable operation.
The coarse adjustment prescribed by this bulletin should
result in combustion settings that allow for ignition and
are a starting point for further adjustment. If, after
following the procedure above, the boiler will not ignite
or, during combustion analysis, the analyzer reads less
than 1.0% O2, contact Weil-McLain Technical Services for
assistance.