Repair manual

MT3855
2
COMPUTER CONTROL SYSTEM
POSSIBLE CAUSE(S) SUGGESTED REMEDY
Symptom #1 - Computer controller displays: PROBE Ć OPEN Ć PROBE Ć SHORT and
alarm buzzer sounds
 Internal problem with computer controller.
 Loose connections at computer controller.
 Shorted or open RTD probe.
 Verify display integ. in the 2nd level programĆ
ming. If the controller has been programmed the
computer may need to be replaced.
 Tighten connections.
 Use the chart on page 6-10 of the Technical ApĆ
pendix to determine if probe is bad. Replace if
necessary.
Symptom #2 - Computer controller displays: ERROR Ć HIGH Ć TEMP Ć LIMIT
 Actual temperature exceeds programmed limit
value. Default 605F (319C).
 Internal problem with computer controller.
 Faulty burner valve relay. Replace relay.
 Verify display integ. in the 2nd level programĆ
ming. If the controller has been programmed the
computer may need to be replaced.