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)
