Thermo Fisher Scientific ULT Freezers
Troubleshooting Guide | 17
Troubleshooting Guide
This section is a guide to troubleshoot general operational problems.
Problem
Cause
Solution
Unit warming.
Unit set to –80°C but can’t
make temperature (Not
reaching set point).
Unit recovers slowly to set
point.
Warm load / Over load.
Allow ample time to recover from loading warm product.
Do not overload cabinet. Refer
in user
manual for loading procedures.
Hot environment.
Check, if the location meets ambient requirements (within
15°C to 32°C or 59°F to 90°F) and away from hot objects.
Dirty condenser and
condenser filter.
Clean condenser and filter. Refer
in user
manual.
Not enough space for air
circulation.
Install the unit in a level area free from vibration with a
minimum of 8" (20 cm) of space on the top and sides, 6"
(15 cm) in back.
Icing/Frost due to high
relative humidity.
Check if the location meets requirements. Maximum
relative humidity 60% for temperatures within 15°C to
32°C (59°F to 90°F).
Excess frost build-up in
chamber.
Defrost the unit. Refer
in user
manual.
Frost build-up on outer
door gasket.
Occasionally scrape the ice on the gasket. Do not use a
sharp tool. Be careful not to puncture the rubber gasket.
Gasket damage.
Check for punctures or tears on gasket. Replace if
necessary. Refer
in user manual.
Prolonged door openings.
Avoid opening of door for a prolonged time. Allow ample
time for recovery after door opening.
Inadequate power supply.
Check for proper voltage to the unit.
Either of the compressors
are not working.
Call service.
User interface (Display)
failure.
Breaker switch off.
Check circuit breaker and reset to on position. Always
use a dedicated, properly grounded circuit.
Power failure to the unit.
Power supply stopped /
Breaker switch off.
Confirm that the cord is securely plugged in.
Plug another appliance into the outlet to see if power is
present.
Always use a dedicated, properly grounded circuit.
