Reznor B Unit Installation Manual - Manual (Page 33)

Form I-F/B, P/N 98126 R21, Page 33
10. Maintenance
and Service
WARNING: If you turn off the power supply, turn off the gas. See
Hazard Levels, page 2.
This unit will operate with a minimum of maintenance. To ensure long life and sat-
isfactory performance, a heater that is operated under normal conditions should be
inspected and cleaned at the start of each heating season. If the heater is operating in
an area where an unusual amount of dust or soot or other impurities are present in the
air, more frequent maintenance is recommended.
The following procedures should be carried out at least annually (See Paragraphs
10.2.1-10.2.10 for specific instructions.):

Clean all dirt and grease from the primary and secondary combustion air openings.
 Fan Models - Clean the fan blade, fan guard, and motor.
 Blower Models - Clean the blower, the belt guard, the inlet guard, and motor of all
dirt and grease. Check the blower belt for tension and wear. Replace a worn belt
that may fail before the next scheduled maintenance check. Check that setscrews
are tight to the shaft.
 Check the gas valve to ensure that gas flow is being shutoff completely.
 Clean the heat exchanger both internally and externally.
 Check the pilot burner and main burners for scale, dust, or lint accumulation.
Clean as needed.
 Check the vent system for soundness. Replace any parts that do not appear
sound.
 Check the wiring for any damaged wire. Replace damaged wiring. (See the unit
wiring diagram for replacement wiring requirements.)
10.1 Maintenance
Schedule
10.2.1 Check Operating Gas Valve
WARNING: The operating valve is the prime safety shutoff. All
gas supply lines must be free of dirt or scale before connecting to
the unit to ensure positive closure. See Hazard Levels, page 2.
Carefully remove external dirt accumulation and check wiring connections.
The combination gas valve must be checked annually to ensure that the valve is shut-
ting off gas flow completely.
Instructions:
1) Locate the 1/8” FPT INLET pressure tap on the combination valve (FIGURE 35).
10.2 Maintenance
Procedures
Single-
Stage Valve
Two-Stage
Valve
1/8" INLET
Pressure Tap
1/8” Outlet
Pressure Tap
1/8" INLET
Pressure Tap
1/8” Outlet
Pressure Tap
FIGURE 35 - Gas Valve
2) With the manual valve turned off to prevent flow to the gas valve, connect a
manometer to the 1/8” inlet pressure tap in the valve. NOTE: A manometer (fluid-
filled gauge) with an inches water column scale is recommended.
3) With the field-installed manual valve remaining closed, observe the manometer
for two to three minutes for an indication of gas pressure. No pressure should be
indicated on the manometer.
If the manometer indicates a gas pressure, the field-installed manual gas valve
must be replaced or repaired before the combination gas valve can be checked.
4) If the manometer does not indicate gas pressure, slowly open the field-installed
manual gas valve. After the manometer's indicated gas pressure has reached
equilibrium, close the manual shutoff valve. Observe the gas pressure. There
should be no loss of gas pressure on the manometer. If the manometer indicates
a loss of pressure, replace the combination gas valve before placing the heater in
operation.
NOTE: Operational pres-
sure settings and instruc-
tions for checking pressure
settings are in Paragraph
6.1.
NOTE: Use only
factory-authorized
replacement parts.