Shellab SHO1-2 - Manual (Page 16)

Maintenance and Troubleshooting
16
Table 1 Problems and solutions (continued)
Problem Action
The indicated chamber temperature is
unstable. Temperature range ±1 °C is normal.
1 Check to make sure the fan is working by
checking the fan motor motion and feeling for
air movement in the chamber. Verify movement
of the cooling fan in the back of chamber.
2 Doors opening, air flow from heaters, and air
flow from air conditioner units may radically
change the ambient room temperature.
Stabilize ambient conditions. Assure that the
oven set point is at least 5 °C above the
ambient room temperature.
3 See if the ambient room temperature is
fluctuating.
4 Verify that the unit is not affected by another
temperature source, such as direct sunlight or
direct air conditioning to the unit.
Display and reference thermometer do not
match. There may be a calibration error. To recalibrate
the oven, see “To calibrate the oven” on page
13. Allow two hours for the temperature to
stabilize.
The set point or calibration cannot be adjusted. Turn the entire unit OFF and then ON to reset.
The oven is calibrated at one temperature, but
not at another. This can be a normal condition when the
operating temperature varies widely. For
maximum accuracy, calibration should be done
at or as close as possible to the operating
temperature in use.
Black soot might appear on the oven floor and
walls. Clean the interior oven as specified on page
14.