AUGUST 29, 2014
5
M24G & M36G GAS BOILERS
GAS PRESSURE ADJUSTMENTS
If gas pressure is too low
Check your gas supply line for a restriction. If no restric-
tion exists, check with your Natural gas supplier to provide
at least 5” of water column pressure in the gas supply line.
If no restriction exists and Propane gas is being used, the
tank pressure regulator should be adjusted to supply at
least 11” of water column pressure in the gas supply line.
If this adjustment cannot be made to your satisfaction, the
gas supplier should be notified.
If gas pressure is too high
Adjust the pressure regulator on the boiler gas valve to re-
duce the pressure if Natural gas is being used. If Propane
gas is being used, adjust the pressure regulator supplied
by the gas supplier. If the regulator cannot be adjusted,
notify the gas supplier.
Pressure control switch adjustment
If boiler fails to maintain steam pressure in operating
range, pressure control switch may require adjustment.
1. Start boiler and allow pressure to build up to operat-
ing level - 7 PSI (1kg/cm²).
2. Check boiler pressure gauge. The gas burners should
cycle ON at 5 PSI and cycle OFF at 7 PSI.
3. If boiler does not come on when pressure gauge
reads 5 PSI and does not go off when pressure gauge
reads 7 PSI, proceed as follows:
WARNING
Because power must be on to adjust pressure
switches, be sure to protect against electrical
shock.
a. Remove screw and lift front cover off control box.
b. Hand adjust operating pressure control switch
and high limit pressure control switch by turning
adjusting nut (Knurled knob) clockwise to raise
and counter clockwise to lower actuation point.
Switch should be set so that boiler comes on
when boiler pressure gauge reads 5 PSI and
goes off when gauge reads 7 PSI. Hi limit switch
should be set so that boiler will shut off if pres-
sure reaches 15 PSI.
c. The actuation value (differential) is factory set
and cannot be changed.
d. The cold water condenser thermostat is preset
at factory.
e. Repeat steps, 1, 2, and 3. If 5 to 7 PSI boiler
pressure gauge reading is obtained during boiler
operation, adjustment is correct. If proper adjust-
ment cannot be made contact an authorized ser-
vice agent.
f. After making adjustments, replace cover on pres-
sure switch box and screw.
OPERATING SWITCH
HI LIMIT SWITCH
