This procedure tests the resistance of the RTD. The RTD measures the temperature of the brewing group. As the machine fluctuates in temperature, the resistance will change sending a signal to the board to heat or not heat the machine. Resistance on the voltage meter is measured in ohms. 

Tools Needed: 

Multi Meter

Time Needed: 10 min

Part Tested: 86000-20080 Single Group RTD W/ Molex

Locate the wiring bundle to the brew group, the white wire with a red and white connection is the RTD. Disconnect the Molex connection (white connector)

Set the multimeter to Ohms, typically signified by the omega symbol. 

Insert the probes of the multimeter into the male Molex connection, one in each port of the RTD Molex,  and measure the resistance. The resistance should be 100 Ohms at room temperature. If the machine is heated up the range will be 130-150 ohms 

If the RTD is outside of the specs listed, the part has failed and will need to be replaced.