CHAPTER IV
OPERATOR MAINTENANCE
INSTRUCTIONS
1. TROUBLESHOOTING
A. Table 4 lists the common malfunctions which you may
find during the operation or maintenance of your heater.
B. For additional information, refer to Honeywell Field
Bulletin enclosed in the heater carton.
C. In the event results cannot be obtained after performing
all listed solutions, call the factory.
2. ADJUSTING THE PILOT FLAME
The pilot flame should envelop 3/8 to 1/2 in. (10 to 13
mm) of the tip of the thermocouple or generator.
Refer to Figure 11. To adjust:
WRENCH
BOSS
GAS
INLET
PILOTSTAT
POWER UNIT
Model # MH25NG/LP
MANUAL GAS
CONTROL KNOB
PILOT FLOW ADJUSTING SCREW
(BENEATH COVER SCREW)
Figure 12. Top View of Standard Capacity Gas Control
HS25NG/LP
PROPER FLAME
ADJUSTMENT
Figure 11. Proper Flame Adjustment
A. Remove pilot adjustment cover screw. Refer to
Figure 12.
B. Turn inner adjustment screw clockwise
decrease or counterclockwise
pilot flame.
C. Always replace cover screw after adjustment and
tighten firmly to ensure proper operation.
PRESSURE REGULATOR ADJUSTMENT
(BENEATH COVER SCREW)
STANDARD
PRESSURE
REGULATOR
("A" MODEL)
PILOT GAS OUTLET
(PRESSURE TAPPING
DIRECTLY BENEATH)
12
Installation instructions and Owner's Manual
3/8 TO 1/2 INCH
(10-13 MILLIMETERS)
THERMOCOUPLE
INSTALL LONG
SCREW IN
OUTSIDE CORNER
STEP OPENING REGULATOR
("C" MODEL)
to
to increase