Service Manual

SERVICING
54
5. Look under the heat shield as the unit is running.
Flames should be drawn into firing tubes.
a. If only one burners flame is not drawn into the tube,
that tube is restricted.
b. If, without the air circulation blower running, all
flames are not drawn into the tubes either the
collector box, combustion blower, or flue outlet is
obstructed. If the combustion blower or flue outlet
is obstructed, the pressure switch should have
opened preventing the unit from firing, also inspect
the unit pressure switch and wiring.
c. If the burner flame is not drawn into the tube only
when the air circulation blower is running, then a
cracked heat exchanger tube is present.
S-303 TESTING INDUCER MOTOR
HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing this unit. Multiple power
sources may be present. Failure to do so
may cause property damage, personal injury
or death.
1. Disconnect the motor wire leads from its connection
point at integrated ignition control module.
2. Using and ohmmeter, test for continuity between each of
the motor leads.
3. Touch one probe of the ohmmeter to the motor frame
(ground) and the other probe in turn to each lead.
If the windings do not test continuous or a reading is obtained
to ground, replace the motor.
4. After completing check and/or replacement of induced
draft blower motor.
5. Turn on electrical power and verify proper unit operation.
S-304 TESTING GAS VALVE
Direct Spark Ignition (DSI) Systems
A combination redundant operator type gas valve which
provides all manual and automatic control functions required
for gas fired heating equipment is used on single stage
models.
A two-stage combination redundant operator type gas valve
which provides all manual and automatic control functions
required for gas fired heating equipment is used on two stage
models.
The valve provides control of main burner gas flow, pressure
regulation, and 100 percent safety shut-off.
HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing this unit. Multiple power
sources may be present. Failure to do so
may cause property damage, personal injury
or death.
1. Ensure gas valve and main gas supply are on.
2. Using a voltmeter, check for 24 volts as noted below for
1- and 2- stage gas valves.
a. For 1-stage gas valves, check from the purple and
blue wires.
b. For 2-stage gas valves, check from C and M terminals
on the valve.
3. If 24 volts are present and no gas flows through the valve,
replace valve.
W/R 36G22-202
WHITE RODGERS MODEL 36G 1-STAGE GAS VALVE
Outlet
Inlet
Outlet Pressure
Tap
Inlet Pressure
Tap
Gas Valve
On/Off
Switch
W/R 36G54-238
WHITE RODGERS MODEL 36G 2-STAGE GAS VALVE