7.4
No Heating
• Verify that the unit is pumping properly.
• If the heat light is not lit, check the control temperature set point and bath temperature to verify
that heating is required.
• Verify that the liquid in the bath covers the heater coils.
• Check that the Software High Limit value has not been exceeded (FLt 1 appears on the display).
7.5
Insufficient Heating
• Verify that the unit is pumping properly.
• Check for proper line voltage.
• Check for excessive external cooling load on unit.
• At higher temperatures, insufficient heating could be due to excessive heat loss from tanks, hoses,
or vapor from the tank.
• Check that the heat demand from connected devices or experiments does not exceed the heating
capabilities of the unit.
• Allow sufficient time for bath temperature to stabilize when changes in heat load or set point are
made.
7.6
No Cooling or Insufficient Cooling
• Check that the Cooling switch is ON.
• If the cooling light is not lit, check the control temperature set point and bath temperature to verify
that cooling is required.
• Check for low or high line voltage.
• Check for blocked airflow through ventilation screens.
• Check ambient air temperature. Refrigeration unit should not be operated above 32°C ambient
temperature as high air temperature may cause the refrigeration compressor to temporarily shut
down.
• Check for excessive heat being transferred to the bath liquid as this may exceed the cooling
capacity of the refrigeration system.
7.7
Triac Failure
• (FLt4) appears on the display, indicating that the heater triac has failed or line supply voltage has
a source of extreme interference from other equipment. Plug the unit into another power source.
If it still displays triac failure, a triac or triac driver needs replacement.
