Troubleshooting
DHB2-20 4-Pan Holding Bin - Pass Thru
The controller incorporates some diagnostic hardware and software to aid in troubleshooting problems. The display will flash the problem if detected when the heater in question is selected.
Problem |
Cause |
Solution |
|
A. Display flashes "Opn" & "rEL" |
Open relay. Circuit inoperable. |
Replace Power Circuit Board. |
|
B. Display flashes "SHr" & "rEL" |
Shorted relay. Circuit inoperable. |
Replace Power Circuit Board. |
|
Open heater. |
Test heater resistance. Replace heater. |
|
|
Unplugged ribbon cable between Power and Main Circuit Boards. |
Verify ribbon cable connection. |
|
|
C. Display shows "LLL" |
Temperature is below 75° F (normal operation) |
N/A |
|
Display shows "LLL" for an extended period of time. |
Heater inoperable. |
Test heater resistance. Replace heater. |
|
Probe inoperable. |
Check for open thermocouple wires from probe. Replace heater/probe assembly. |
|
|
Display shows "LLL" and then changes to "Opn"& "rel" and heater surface temperature is cool. |
Circuit inoperable. (see A). |
See A above. |
|
Display shows "LLL" and then changes to "SHr"&"rEL" and heater surface temperature is cool. |
Circuit inoperable. (see B) |
See B above. |
|
D. Display shows "HHH" for an extended period of time and heater surface temperature is hot. |
Temperature is above 400° F (abnormal operation) |
Diagnostic circuit inoperable. Replace Power Circuit Board.See B above. |
|
Display shows "HHH" for an extended period of time and heater surface temperature is cool. |
Probe is inoperable. |
Check for pinched thermocouple wires from probe. Replace heater/probe assembly. |