S-303 Testing Inducer Motor; S-304 Testing Gas Valve; S-306 Checking Orifices; S-307 Checking Gas Pressure - Daikin DP14UM Service Instructions Manual

SERVICING
Checking Flame Rollout Switch
Limit Switch Operation (Applies to Primary, Auxiliary,
and Roll Out Limits) DSI systems.
If a limit switch opens, the indoor blower is energized on
heat speed and the induced draft blower is energized. The
LED on the control flashes "4" to indicate an open limit
switch. The blower and inducer remain on while the limit
switch is open. The gas valve is de-energized. Power to
the thermostat "R" is removed while the limit switch is
open.
When the limit switch re-closes, the induced draft motor
runs through its post purge and the indoor blower goes
through the heat off delay.
If a call for heat exists when the limit switch re-closes, the
control goes through a pre-purge period and then makes
an ignition attempt. The indoor blower remains on (for the
delay off time) during the re-ignition attempt.
1. If no voltage is measured on either side of control it
indicates ignition control or wiring to control problem.
2. If voltage is measured on one side of the control and
not the other, it indicates the control is open.
3. If voltage is measured on both sides of the control the
wiring to gas valve or valve is at fault.

S-303 Testing Inducer Motor

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. 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.

S-306 Checking Orifices

Orifices should be treated with care in order to prevent
damage. They should be removed and installed with a box-
end wrench in order to prevent distortion. In no instance
should an orifice be peened over and redrilled. This will
change the angle or deflection of the vacuum effect or
entraining of primary air, which will make it difficult to
adjust the flame properly. This same problem can occur if
an orifice spud of a different length is substituted.
Disconnect Gas and electrical power supply.

S-307 Checking Gas Pressure

Gas inlet and manifold pressures should be checked and
adjusted in accordance to the type of fuel being consumed.
WARNING
WARNING
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