4
Figure 1b: Gas Valve Detail (150MBH, 180MBH)
Table 2: Starting Number of Throttle Turns For
Conversion To LP Gas
Boiler
Size
# Counterclockwise Turns
(From Fully Closed)
080
100
3
120
4
150
5-3/4
180
6-1/2
WARNING
Throttle adjustments shown in Table 2 are approximate. The fi nal throttle setting must be found using a
combustions analyzer. Leaving the Boiler in operation with a CO level in excess of 200PPM air-free could
result in injury or death from carbon monoxide poisoning. Leaving the Boiler in operation with a CO
2
level
outside of the range shown in Table 3 could also result in injury or death from carbon monoxide poisoning,
even if the Boiler is operating at an air-free CO level below 200PPM during this adjustment procedure.
If the throttle is very far out of adjustment on the “rich” (counter-clockwise) side, the Boiler burner may
be running at 0% excess air or even with a air defi ciency. Operating the Boiler in this condition may cause
property damage, personal injury or loss of life. Under these conditions, most combustion analyzers used
in the fi eld will show 0% O
2
and a very high (over 1000PPM) CO. Combustion readings will also appear to
be unresponsive to throttle adjustment. If the Boiler appears to be operating under this condition, turn the
throttle screw clockwise until the fl ame lengthens signifi cantly and is mostly blue. Then, slowly turn the
throttle counter-clockwise, using a combustion analyzer to achieve the required CO
2
as described in these
instructions.
