Service manual

SERVICING

DSI Direct Spark Ignition Systems

WARNING

Disconnect Electrical Power Supply:

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.

With Power ON:

WARNING

LINE VOLTAGE NOW PRESENT.

4. Place the unit into a heating cycle.

5. As soon as flame is established a microamp reading

should be evident once proof of flame (microamp read-

ing) is established, the hot surface ignitor will be de-

energized.

Flame Sensor

Spark

Igniter

6. The nominal microamp reading is 4 microamps.

7. If the microamp current is less than 1 microamp, the

ignition control will flash a code of 7 flashes. If the

microamp current is less than 0.4 microamps, the con-

trol will lockout and flash a code of 1 flash after attempt-

ing to restablish flame sense.

8. If the microamp reading is less than the minimum speci-

fied, check for high resistance wiring connections, the

distance (3/16") between the sensor and burner, flame

sensor connections or poor grounding.

9. 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 emery cloth or steel wool. Do not use sand

paper, the silicone in sand paper will further contaminate

the sensor.