Testing Gas Valve; Checking Main Burners; Checking Orifices - Daikin APGM3 Service And Troubleshooting

SERVICING
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.

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. 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/R36J22-202
White Rodgers Model 36G22 1-Stage Gas Valve
WARNING
W/R36G54-238
White Rodgers Model 36G 2-Stage Gas Valve

Checking Main Burners

The main burners are used to provide complete
combustion of various fuels in a limited space, and transfer
this heat of the burning process to the heat exchanger.
Proper ignition, combustion, and extinction are primarily
due to burner design, orifice sizing, gas pressure, primary
and secondary air, vent and proper seating of burners.
Beckett Burner
Disconnect Gas and electrical power supply.
In checking main burners, look for signs of rust, oversized
and undersized carry-over ports restricted with foreign
material, etc.

Checking Orifices

A predetermined fixed gas orifice is used in all of these
furnaces. That is an orifice which has a fixed bore and
position.
WARNING
A
GAS
STREAM B
36