Thermo Scientific HPS RT2 Advanced Manual page 48

Section 7
Troubleshooting
Problems During Operation
No heat
No or too slow temperature change
during heating
Stir bar decoupling
Knocking noise during stirring
Abnormal speed control operation
Knob malfunction
LED display malfunction
Probe lamp is not ON
7-2 Hotplate & Magenetic Stirrer
Cause
Failure to push RUN/STOP button
Set point value is lower than present
temperature value.
Power cut-off by built-in overheat
prevention circuit
Internal circuit failure
Button switch failure
Probe is not enough soaked into the media.
Too low setting of the heating level
Too much media
Internal circuit failure
Too much media
High viscosity of the media
Decreased magnetic strength of stir bar
Uneven bottom of the vessel
Loosened internal parts
Too much media
Internal circuit failure or damaged motor
Damaged knob
Damage due to chemical spill or overheat
Probe connection failure.
Damage due to chemical spill or overheat.
Corrective Action
Push RUN/STOP button.
Adjust Set point lower than Present
temperature value.
Turn off the main power switch and wait
until the heater cools down. Then, turn
on the main power switch.
Contact Thermo Scientific for service
Contact Thermo Scientific for service
Soak probe into the media more than
20mm of it.
Turn the heater knob clockwise to
increase the heating level
Reduce the media volume.
Contact Thermo scientific for service.
Reduce the media volume or increase
the rpm more gradually.
Increase the rpm more gradually or
change the stir bar with a small friction
resistance one (ex. cone type).
Replace the old stir bar with a new one.
Use a vessel with thin, flat bottom.
Contact Thermo Scientific for service.
Reduce the media volume.
Contact Thermo Scientific for service.
Take out the knob and relocate it.
Contact Thermo Scientific for service.
Contact Thermo Scientific for service.
Reconnect probe in right way.
Contact Thermo Scientific for service.
Thermo Scientific