ELECTRIC COMBI OVENS - TROUBLESHOOTING
TROUBLESHOOTING
WARNING: CERTAIN PROCEDURES IN THIS SECTION REQUIRE ELECTRICAL TEST OR MEASUREMENTS WHILE POWER IS APPLIED TO THE MACHINE. EXERCISE EXTREME CAUTION AT ALL TIMES. IF TEST POINTS ARE NOT EASILY ACCESSIBLE, DISCONNECT POWER, ATTACH TEST EQUIPMENT AND REAPPLY POWER TO TEST.
Before performing any of the troubleshooting checks listed below, run the oven control in “DIAGNOSTIC TEST MODE” for the oven control in use, as outlined under “SERVICE PROCEDURES AND ADJUSTMENTS”. By utilizing the oven controls “diagnostic test mode” the Service Technician can quickly and easily determine if a component is functioning properly or in need of repair. The “diagnostic test mode” can be entered only when the machine is OFF. If the oven is inoperative, then refer to the troubleshooting guide under SYMPTOM - “Oven inoperative and displays are blank” and/or SYMPTOM - “Button(s) on keypad inoperative”. Also, check the Technical Service Bulletins for changes to the oven and for software revisions to the oven control.
NOTE: An accumulation of lime scale on the water level sensors may cause false water level readings to the oven control. Lime scale that is dry can prevent the sensor from detecting the water level until the lime becomes moist enough to conduct the electrical signal. This condition can cause water errors and/or overfilling of the steam generator. In reverse, lime scale that retains water may already be moist enough to conduct the electrical signal. This condition can cause water errors, prevent the steam generator from filling and cause dry firing of the heating elements. Subsequently, the steam generators thermal fuse(s) would open to protect the oven. See “CLEAN CYCLE MODE - STEAM GENERATOR DELIMING” under “SERVICE PROCEDURES AND ADJUSTMENTS”.
SYMPTOM |
| POSSIBLE CAUSES |
|
|
|
Water error light on, buzzer sounds for one | 1. | Time to fill steam generator has exceeded 4 minutes 20 |
minute and steam generator light comes on |
| seconds. |
in a cooking mode. |
| A. Ensure water supply is on. |
|
| B. Check water fill line for clogs. |
| 2. | Water too soft for water level sensors to conduct |
|
| electricity. |
| 3. | Lime scale build up (dry) on water level sensors giving a |
|
| false reading to the oven control. See note at the |
|
| beginning of troubleshooting section. |
|
|
|
Water error light on and buzzer sounds after | 1. | Water still in steam generator - check for clogged steam |
steam generator drains. |
| generator drain line or drain pump malfunction. |
| 2. | Lime scale build up (moist) on water level sensors giving |
|
| false reading. See note at the beginning of |
|
| troubleshooting section. |
|
|
|
Water error light on and buzzer sounds | 1. | Water still in steam generator - check for clogged steam |
when oven is turned on. |
| generator drain line or drain pump malfunction. |
| 2. | Lime scale build up (moist) on water level sensors giving |
|
| false reading. See note at the beginning of |
|
| troubleshooting section. |
|
|
|
Steam generation stops, water error light | 1. | Oven control board has not seen a call for water request |
and steam generator light on in steam |
| within 5 minutes powering on. A boil down situation is |
mode. |
| assumed. |
|
| A. Lime scale build up on water level sensors giving |
|
| false reading. See note at the beginning of |
|
| troubleshooting section. |
|
| B. Oven control board malfunction. |
|
|
|
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