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Thermo Fisher Scientific

Temperature fluctuation issues


Temperature fluctuation issues


TSX Lab Refrigerators TSX Blood Bank Refrigerators TSX -30° Lab Freezers TSX -30° Plasma Freezers TSX -20° Laboratory and Enzyme Freezers  Models Energy Star Model
TSX1205G TSX1204B TSX1230F TSX1230L TSX2320F V/Y/Z A/D
TSX1205S TSX2304B TSX2330F TSX2330L TSX3020F V/Y/Z A/D
TSX1205P TSX3004B TSX3030F TSX3030L TSX2320E V/Y/Z A/D
TSX2305G TSX5004B TSX5030F TSX5030L TSX3020E V/Y/Z A/D
TSX2305S         V/Y/Z A/D
TSX2305P         V/Y/Z A/D
TSX2305C         V/Y/Z A/D
TSX3005G         V/Y/Z A/D
TSX3005S         V/Y/Z A/D
TSX3005P         V/Y/Z A/D
TSX3005C         V/Y/Z A/D
TSX4505G         V/Y/Z A/D
TSX4505C         V/Y/Z A/D
TSX5005G         V/Y/Z A/D
 TSX5005S         V/Y/Z A/D
TSX5005P         V/Y/Z A/D
TSX5005C         V/Y/Z A/D


Troubleshoot Temperature Control
  1. Make sure that the control is set correctly. Refer to Figure 1.
  2. You can enter the programming mode by pressing the Scan button (SCAN) and holding for 5 seconds. The display will then flash "Prg" to indicate that you have entered the programming mode. 
  3. Use (+) and (-) buttons to modify the values and press the scan (SCAN) button to save the value and go to the next screen.

Figure 1: Setpoint Programming Functions:

Screen Button Function Summary
1 Initial Screen Unit Set point The temperature that the unit is set to run
2 Press Scan  Cold Alarm Temperature The temperature that will actuate the cold alarm (if active)
3 Press Scan  Warn Alarm Temperature The temperature that will actuate the warm alarm (if active)
4 Press Scan  Exit Program Mode Returns to normal operating screen

Note: If the unit is left idle for a period of 30 seconds during program mode, the program mode shall be exited. If at any point the scan button is pressed and held for a period of 10 seconds, the unit shall enter the service mode.  

Clogged Condenser

Be advised:

  • Clean the condenser filters every three months.
  • There is one condenser filter located in the back cage of the unit that can be accessed without removing the back cage or disconnecting the power. 
  • Condensers should be cleaned at least every six months; more often if the laboratory area is dusty.
  • In heavy traffic areas, condensers load with dirt more quickly.
  • Failure to keep the condenser clean can result in equipment warm-up or erratic temperatures.

To clean the filter, complete the following steps:

1. Remove the filter by pulling upwards through the slot in the back cage.

2. Shake the filter to remove loose dust.

3. Rinse the filter in clean water.

4. Shake the excess water from the filter and let it dry.

5. Reinstall filter by pushing downwards through the slot in the back cage.

To clean the condenser, complete the following steps:

1. Disconnect the power.

2. Remove the filter.

3. Vacuum the condenser and clean up any loose dust.

4. Replace the filter.

5. Reconnect power.

SAFETY HAZARD CAUTION: Do not pull the filter downwards from the bottom. The condenser has sharp surfaces. Never clean around the condensers with your fingers. Some surfaces are sharp. The condenser is located in the top rear of the machine compartment.

Solution Bottles
  • Make sure the solution bottles for the temperature sensors are full.
  • The solution is a 50/50 mixture of glycerin and distilled water.


The possible causes of this issue include:

  • Temperature control issues
  • Clogged condenser
  • Solution bottles not full