Installation, Operation & Maintenance Manual
IM-895
15
Maintenance
(cont.)
Gas Train
An annual inspection of the gas control assembly should be made. Internal and external piping should be checked for leaks. Relief
vents on gas controls should be checked for clogging.
Air Pressure Switches
An annual check of the tube for the airflow switch, and the entering and leaving side of building pressure switches, should be
made to ensure against blockage.
Discharge Air Sensor
Remove the cover from the sensor assembly junction box, which will expose the temp sensor module (see page 9). Remove the
two screws that hold the sensor module in the junction box. The sensor assembly junction box does not get removed. Insert a
bottle brush into the sensor sampling tube to clean out any dust or dirt, then replace the sensor module and junction box cover.
Gas and Electric Controls
Inspect for general cleanliness and tightness of electric and mechanical connections.
Put the system back into operation and view the burner from the downstream side while cycling the burner through its full firing
range. A good flame will be blue, with minimal yellow "fingers". The flame length in forced "high fire" should be 12-18" long.
Procedure for Extended Shutdown Periods
If the unit is to be shut down for an extended period of time, the following precautions should be followed:
1. Turn off all manual shutoff valve(s) in the gas train of the unit and in the gas supply line to the unit.
2. Turn off the electric supply to the unit at the unit disconnect. Lock the disconnect to prevent tampering.
3. Protect outside air openings to prevent the unit from being soiled.
Troubleshooting Guidelines
PROBLEM
POSSIBLE CAUSE
POSSIBLE REMEDY
A. Power Failure
1. Disconnect not turned on
1. Turn on disconnect
2. Blown fuses
2. Check and replace
3. Main to unit disconnect not on
3. Turn on power at main
B. Motor Not
Operating
1. Disconnect not turned on
1. Turn on disconnect
2. Blown fuses
2. Check and replace
3. Main to unit disconnect not on
3. Turn on power at main
4. Failed motor
4. Check and/or replace
5. Loose wiring to motor
5. Check and tighten
6. Motor overloaded
6. Check for proper speed
7. Improper supply voltage
7. Check and correct
8. Motor overheating
8. Check firing rate of unit
C. Blower Not
Operating
1. See Problems "A" and "B"
1. See Problems "A" and "B"
2. Broken drive belt(s)
2. Check and replace
3. Bearings seized
3. Check and replace
Do not reuse any mechanical or electrical component that has
been wet. Such components must be replaced.
CAUTION
NOTICE
To check most of the Possible Remedies in the troubleshooting
guide listed, refer to the applicable sections of the manual.
When servicing or repairing this equipment, use only factory-
approved service replacement parts. A complete replacement
parts list may be obtained by contacting the factory. Refer to
the rating plate on the unit for complete unit model number,
serial number and company address. Any substitution of parts
or controls not approved by the factory will be at owner's risk.
WARNING