Four-Way Valve - Lennox MPA009S4S Service Manual

29.4. Four-Way Valve

a. Power on, use a digital tester to measure the voltage, when the unit operates in cooling, it is 0V. When the unit operates
in heating, it is about 230VAC. If the value of the voltage is not in the range, the PCB must have problems and needs to
be replaced.
b. Turn off the power, use a digital tester to measure the resistance. The value should be 1.8~2.5 KΩ.
Figure 78. Measure Voltage
Figure 79. Measure Resistance
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