Checking Pressure Transducer; Checking For Delayed Ignition; Field Test Mode - Daikin DP14UM Service Instructions Manual

SERVICING
Disconnect Gas and electrical power supply.
NOTE: Use adapter kit 0151K00000S to measure gas
pressure on White-Rodgers 36J22 gas valves.
1. Connect a digital manometer or adequate gauge to
the inlet pressure fitting of the gas valve.
2. Remove the pressure tap fitting at the manifold if
provided or check at the gas valve outlet fitting and
connect another manometer or gauge.
White Rodgers Model 36J22 Gas Valve
Measuring Inlet and Manifold Gas Pressure
With power ON:
Line voltage now present
3. Put furnace into heating cycle and turn on all other
gas consuming appliances.
A. Inlet pressure should be a nominal 7" w.c.
B. Measure gas manifold pressure with burners
firing. Adjust manifold pressure using the table
below.
Manifold Gas Pressure
Natural Gas 2.8" - 3.2" w.c.
If operating pressures differ from above, make necessary
pressure regulator adjustments, check piping size, etc.,
and/or consult with local utility.
30
WARNING
WARNING

Checking Pressure Transducer

The pressure transducer is a pressure sensing device that
allows the control to modulate the inducer motor through
the heating cycle. The transducer contains electronic
circuitry and must not be subjected to any voltage source
other than factory wiring. Refer to the Troubleshooting
chart beginning on page ?? for diagnosing suspected
issues.
Pressure Sensor: The pressure sensor is mounted near
induced draft blower. Its function is to regulate the induced
draft blower's speed in order to maintain proper air-fuel
ratio for clean and reliable combustion. The pressure
sensor also guards against insufficient airflow (combustion
air and flue products) through the heat exchanger.
The pressure sensor should read approximately -2.5 in.
w.c. for the 40,000 BTU/hr models, -2.2 in. w.c. for the
60,000 BTU/hr models and -1.9 in. w.c. for the 80,000 BTU/
hr models.
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.

Checking For Delayed Ignition

Delayed ignition is a delay in lighting a combustible mixture
of gas and air which has accumulated in the combustion
chamber. Delayed ignition can also occur due to faulty
igniter.
If delayed ignition should occur, the following should be
checked:
1. Improper gas pressure – adjust to proper pressure.

Field Test Mode

Function: When the SW1 button is pressed and held until
the LED is blinking in AMBER (more than 10 seconds, less
than 15 seconds), the control will execute a field test mode
sequence to cycle through component operation.
Operation: The control must be powered and the
thermostat satisfied (no call for heat or cool). Depress and
hold the SW1 button for more than 10 seconds, but less
than 15 seconds until the LED is blinking in AMBER, then
release. The control will execute the following functions:
1. Blower – "Heat" Speed for 15 seconds
2. Blower – "Cool" Speed for 15 seconds
WARNING