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FAQ

Fault: “E5 Heater UnderTemp.” What should I do?

To get this fault, the temperature sensor in one or more paddle heaters is reporting low temperatures. This could occur at different times under specific conditions such as:

  • During paddle pre-heat, if any one of the paddles does not reach 50°C in five minutes.
  • During the Amylase phase, if any one of the paddle sensors does not reach 90°C in 25 minutes. This also applies to Trizma phase in the AOAC 2009.01/2011.25 methods.
  • During the AMG or Protease phase, if any of the paddle sensors fail to maintain at least 45°C (temperature range is 60°C +10/-15°C). This also applies to the Protease phase during AOAC 2009.01/2011.25 methods.

Should any one of these conditions be met during a run, the suspect heater/station will shut down and stop heating. The run will otherwise continue as normal. The E5 error message on the touchscreen display will indicate which station(s) are reporting the under-temp fault and what the temperature was at the time of the fault. This may be an actual under-temp condition, or it may be erroneous due to a connectivity issue. Either way, the affected heater will be shut down by the program and the run will continue. If this were to occur during the IDF phase, with the heater shut down, digestion would likely not occur as normal, and the test results would not be reliable for this station. 

Below is a list of potential causes of the E5 fault:

(1) Bag breakage: Confirm that an IDF or Flow-Thru filter bag did not break during one of the heating periods. If a filter bag were to leak near Clamp Bar B, and if fluids were to get on one of the paddles, the liquid evaporation would drop the paddle temperature and possibly cause this fault. If this has occurred, the instrument is sensing a real drop in temperature at the wetted paddle, and no repair to the instrument is needed. Clean the area affected by the leaked bag. Test results from a broken bag should be disregarded.

(2) Greater volume in the IDF or Flow-thru bags: Confirm that the volume calibration is accurate. Rerun the volume calibration as described in the TDF Operator's Manual (QC/Calibration Checks section). If, for example, the volume calibration is significantly off, there could be an average of 50mls of buffer delivered instead of the required 40mls. This would create a delay in reaching the temperature.

(3) Pre-heat of paddles has been bypassed: In Diagnostics, there is an option under Service Mode to Bypass Amylase Phase Initial Heat-up. If this has been inadvertently pressed (stating "YES") this will bypass the paddle preheat to 50°C and take longer to heat up once the Buffer/Amylase is added. Make sure this option says "NO." This feature is typically used only for demo purposes.

(4) Clamp Bar A is left open: If, for any reason, Clamp Bar A was left open during the Amylase phase heat-up, there will be more evaporative cooling which will require more time to heat the bags. NOTE: Normally, Clamp Bar A will close automatically after the final delivery to the IDF positions, but it can be re-opened.

(5) Front cover left open or localized draft: Be sure to use the front safety cover, especially during the Amylase phase. If this cover is left open, and/or there is a nearby A/C vent creating a draft toward the front of the instrument, the Amylase phase heat-up will take longer. Also, if the TDF instrument is located inside a hood, turn off the airflow to the hood during the Amylase phase heat-up. The continued upward airflow will create a significant delay in reaching temperature. Addressing these may resolve the problem.

(6) Alcohol - Buffer containers connected incorrectly: Ensure that the containers are connected correctly to the color-coded supply lines on the right side of the instrument. Confirm that alcohol did not inadvertently get put in the buffer container, and that buffer was not put in the alcohol containers. If either of these things happens, and alcohol gets dispensed to the IDF bags at the start of the Amylase phase, the alcohol will boil at a much lower temperature and not reach the target temperature of 97°C.

If the E5 fault was not the result of one of the above issues, run a brief test to see if all the paddle heaters are heating normally.  

  1. Allow the paddles to return to room temperature.  
  2. Obtain a stopwatch and six Flow-thru bags (used bags will work for this test).  
  3. Use a heat sealer to seal the bottom edge of the bags. This will make removal later easier. Install these in the IDF positions.  
  4. Connect the Flush Tubing Assembly (Part #: TDF70) to the HCl, three enzymes, buffer, water, and two alcohol connection points on either side of the instrument. Connect the middle connector to a filled Distilled Water container.  
  5. From the Select a Function screen select a 991.43 TDF run. Answer all the prompts affirmative and press START.  
  6. Press the "Display Temps/Pressures" button to monitor the temperature readings and watch the time that they reach 50°C. They should reach this temperature in about two to two and a half minutes depending on the ambient starting temperature. Note the amount of time required. Reset your timer. As soon as Amylase and Buffer are delivered, the mixing will start. Restart your timer now. Use the chart below to record every two and a half minutes. The time it takes for each paddle to reach 90°C. T0 is the end of the fluid delivery to the bags and the start of mixing. Once they all reach 90°C, press ABORT to end the run, and allow the bags to cool before removal.


If the suspected paddle heater takes significantly longer to heat than the others or fails to heat up, there is a problem with either the heater within the Paddle Bar Assembly or with the I/O2 circuit board. If the paddles heat to the touch but one of the sensors shows an erroneous low reading, there is a problem with the sensor, and the paddle bar will need to be replaced, or with the newer style Paddle Bar Assembly, the individual paddles (Part #: TDF48) can be replaced (Contact ANKOM to verify which paddle assembly you have).
 
For further assistance, contact ANKOM Technology at www.ankom.com/contact/technical-services or (315) 986-8090. Refer to TDF Service Procedure Paddle Bar Replacement (TS021) and follow the replacement instructions for the Paddle Bar Assembly (Part #: TDF23). 

If one of the paddles fails to heat normally and to rule out a problem with the I/O-2 circuit board, remove the back and top panel of the Electrical Enclosure so that the I/O-2 circuit board can be seen. Do not touch the wiring. Perform this simple test: 

  1. In Diagnostics, select Heater Test. 
  2. Select Paddle Heater Power Enable. 
  3. Check that LED #2 lights on the I/O-2 board in the electrical enclosure. 
  4. Leaving the above enabled, select Paddle #1, and inspect the LED (refer to the bullet points below for each LED).
  5. Repeat for each paddle heater. The following is a list of the paddles and the corresponding LED #:
  • Paddle Heater Power Enable - LED 2
  • Paddle 1 - LED 15
  • Paddle 2 - LED 12
  • Paddle 3 - LED 9
  • Paddle 4 - LED 7
  • Paddle 5 - LED 4
  • Paddle 6 - LED 1
  1. Turn the heaters off after each test. If the appropriate LED is not lighting up, the problem may be with either the power supply or the I/O2 circuit board.  

To test the power coming from the power supply to the individual paddle heater, you will need a voltmeter set to DC. Connect the red lead on the voltmeter to the #20 position on the 24-volt DIN rail. Now, turn all the heaters on and test the voltage as follows. On the back of the I/O2 circuit board are two 10-pin connectors labeled CN-3 and CN-4. To test the power going to each paddle, touch the black lead of the voltmeter to the following contact.  

  • Paddle 1 - CN4, #2 position (wire label 53)
  • Paddle 2 - CN4, #5 position (wire label 50)
  • Paddle 3 - CN4, #8 position (wire label 47)
  • Paddle 4 - CN3, #2 position (wire label 45)
  • Paddle 5 - CN3, #5 position (wire label 42)
  • Paddle 6 - CN3, #8 position (wire label 39)

You should detect 25.0 volts +/- 0.2 volts at each circuit. If the voltage is low, there may be a problem with the power supply or voltage adjustment. To replace Power Supply B (Part #: TDF110), refer to Service Procedure Power Supply B Replacement (TS032). 
 
If all the LEDs are lighting up as normal and the voltage is normal, the problem is with a paddle heater within the Paddle Bar Assembly. To replace the Paddle Bar Assembly (Part #: TDF23), refer to Service Procedure Paddle Bar Replacement (TS021) and follow the instructions. Or, with the newer style Paddle Bar Assembly, the individual paddles (Part #: TDF48) can be replaced by referring to Service Procedure Paddle Replacement (TS042). Contact ANKOM to verify which paddle assembly you have. 
 
For further assistance, contact ANKOM Technology at www.ankom.com/contact/technical-services or (315) 986-8090.