Checking Flame Sensor - Daikin M Series Service And Troubleshooting

SERVICING
pin connector and wires from compressor
unloader solenoid to 6 pin connector on board.
If connector and wires check good, replace
control.
2. Board set for 1 stage thermostat:
A. Wait the selected delay time (either 5 or 10
minutes, depending on jumper setting)
B. Check for 24 volts at compressor unloader
solenoid.
C. No voltage - check 6 pin connector and wires
from compressor unloader solenoid to 6 pin
connector on board. If connector and wires check
good, replace control.
LED
Flashes/Status
Internal Control Fault, Micro Controller
Detected Hardware Failure, or Gas Valve
Off
Detected Energized When it Should be
De-energized
1 Lockout Due to Excessive Retries
2 Pressure Switch Stuck Open
3 Pressure Switch Stuck Closed
4 Open High Temperature Limit
Flame Present Outside the Flame
5
Detect Mode
6 Compressor Short Cycle Delay Active
Limit Opened Five Times within the
7
Same Call for Heat
Indoor Thermostat/Outdoor Thermostat
8
is Open
Pressure Switch/Loss of Charge Switch
9
is Open
Steady ON Normal
Red LED Fault Codes
LED
Flashes/Status
Flame Present Outside the Flame Detect
2
Mode
1 Low Flame Signal Current
Steady ON Normal Flame
OFF No Flame Present
Amber LED Flame Status Codes
NOTE: The flash rate is 0.25 seconds on, 0.25 seconds
off, with a 2-second pause between codes.

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.
System Condition
Flame Condition
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.
Flame Sensor
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 hot surface ignitor will be
de-energized.
7. The nominal microamp reading is 4 microamps.
8. If the microamp current is less than 0.5 microamp the
control will lockout and flash a code of 1 flash after
attempting to reestablish flame sense.
9. If the microamp reading is less than the minimum
specified, check for high resistance wiring
connections, the distance (3/16") between the sensor
and burner, flame sensor connections, dirty flame
sensor or poor grounding.
10. If no reading, check for continuity on all components
and if good - replace ignition control module.
NOTE: Contaminated fuel or combustion air can
create a nearly invisible coating on the flame sensor.
This coating works as an insulator causing a loss in
the flame sense signal. If this situation occurs the
flame sensor must be cleaned with steel wool. Do not
use sand paper, the silicone in sand paper will further
contaminate the sensor.
WARNING
Flame
Sensor
WARNING
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