Water temperature sensor error.

Main PCB detects that the thermistor is open or shorted.

Possibly incoming water temperature greater than 194ºF.


Check temperature sensor for proper readings.

Check temperature of customer’s hot water.


1.) Is the incoming water temperature at or above 194°F?
If so, the water supply temperature will need to be lowered.

2.) Check for loose connections at the thermistor and Main PCB.

 3.) Locate the thermistor harness connection at the Main PCB.
With the unit turned on, measure the voltage across the thermistor.
-If 0Vdc is measured, the thermistor is shorted.
-If 5Vdc is read, the thermistor or wiring harness is open or the thermistor is unplugged.


The thermistor resistance can also be checked from the Main PCB.
– At room temperature the thermistor should read 10-14K ohms.

Wiring diagram example from LDF5545

4 Responses

  1. RNN230925006167

    Please add a picture of wiring diagram or some way to identify the connector in question or a link to the wire diagram?

    1. the wiring diagram for the model you are working on is used as the example in the article.
      But we can not add every models wiring diagram in every error code.
      If you need a wiring diagram we suggest to download the service manual.
      The articles are for quick information and can not be model specific for every model.
      For that you will have to consult the service manual

  2. I got 25vdc at thermistor connection that result isn’t listed. Only open or short. Resistance appears to be normal. There is no indication of what voltage should be or what next step is if all is normal.

    1. all sensor voltages on all appliances are 5vdc from the board and are changed by the resistance of the sensor.
      If you ever read 25Vdc on a sensor then the main board is defective as the power supply has lost it’s regulation.
      typically when you get the sensor error it is due to open or shorted on the sensor or wire or the main board has put out the wrong voltage such as less than 0.5vdc or greater than 5vdc as the charts indicate a normal temperature range of resistances and voltages

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