S-314 Checking Flame Sensor - Daikin DP14UM Service Instructions Manual

SERVICING
If the pressure switch opens after the gas valve has been
energized, the control will de-energize the gas valve and
run the indoor blower through the heat off delay. The
inducer stays on until the pressure switch re-closes. Then
the control makes another ignition attempt.
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. Remove wires from the electrical terminals.
2. Using a VOM check from Common to NO (Normally
Open) - should read open.
If switch reads as noted proceed to Step 3, otherwise
replace control.
3. Remove the pressure control hose from the control
and interconnect with a digital manometer as shown:
Reconnect wires to the Common and NO terminals.
With Power ON:
Line voltage now present
4. Energize furnace for heating cycle. The induced draft
blower motor will begin to run. The manometer
should read approximately -1.2" ± 0.3" W.C with no
combustion.
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WARNING
WARNING
5. Remove and check the two electrical wires and using
the VOM check from Common to NO (Normally
Open), it should read closed (with I.D. motor running).
If not as above, replace pressure control.
6. Reconnect all wires to the control and place in
heating cycle.
7. As the unit fires on high stage, the manometer
negative pressure will drop to -1.0" ± 0.3" W.C.
8. If not as listed, replace control.
NOTE: The pressure switch must be mounted with the
diaphragm in a vertical position.

S-314 Checking Flame Sensor

A flame sensing device is used in conjunction with
the ignition control module to prove combustion. If a
microamp signal is not present the control will de-energize
the gas valve and "retry" for ignition or lockout.
DSI Direct Spark Ignition Systems
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 flame sensor wire from terminal FS of
the ignition control module.
2. Connect a microamp meter in series with this wire
and terminal FS.
3. Be sure the negative side of the meter is to the wire
and the positive of the meter is to terminal FS.
4. Turn on Power.
Line voltage now present
5. With Power ON, Place the unit into a heating cycle.
6. As soon as flame is established a microamp reading
should be evident once proof of flame (microamp
reading) is established, the spark ignitor will be de-
energized.
7. The nominal microamp reading is 10 microamps.
8. If the microamp current is less than 3.0 microamp the
control will lockout and flash a code of 1 Amber flash
after attempting to reestablish flame sense.
WARNING
WARNING