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:
PROPER FLAME
ADJUSTMENT3/8 TO 1/2 INCH
THERMOCOUPLE
Figure 11. Proper Flame Adjustment
A.Remove pilot adjustment cover screw. Refer to Figure 12.
B.Turn inner adjustment screw clockwise 
to
decrease or counterclockwise 
to increase pilot flame.
C.Always replace cover screw after adjustment and tighten firmly to ensure proper operation.
| PRESSURE REGULATOR ADJUSTMENT |
|
MANUAL GAS | (BENEATH COVER SCREW) | INSTALL LONG |
| ||
CONTROL KNOB |
| SCREW IN |
WRENCH |
| OUTSIDE CORNER |
|
| |
BOSS |
|
|
| STANDARD |
|
| PRESSURE |
|
| REGULATOR |
|
| (“A” MODEL) |
|
GAS | STEP OPENING REGULATOR | |
(“C” MODEL) | ||
INLET | ||
| ||
| PILOT GAS OUTLET | |
| (PRESSURE TAPPING | |
| DIRECTLY BENEATH) | |
PILOTSTAT | PILOT FLOW ADJUSTING SCREW | |
POWER UNIT | (BENEATH COVER SCREW) |
Figure 12. Top View of Standard Capacity Gas Control
Model # MH25NG/LP | HS25NG/LP | 12 Installation instructions and Owner’s Manual |
