Daikin EHYHBH05AAV3, Service Manual

Page: 152 / 170

Additional Checks for Troubleshooting ESIE13-02A
Part 4 – Troubleshooting 152
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6.3 Check No.3 - Checking the Thermistors
Thermistors If the cause of the problem is related to the thermistors, then the thermistors should be checked prior
to changing the PCB.
For more information about these thermistors, see:
"External connection diagram" (outdoor unit)
"System Operation" on page 22
Overview of
thermistors The table below contains an overview of the thermistors:
* = optional
Checking To check the thermistors, proceed as follows:
Thermistor Description
Hydro-box R1T Outlet water after PHE thermistor
R1T (A2P) Ambient sensor user interface
R1T (A3P)* Ambient sensor ON/OFF thermistor
R2T Outlet water after BUH thermistor
R2T* External sensor (floor or ambient)
R3T Refrigerant liquid thermistor
R4T Inlet water thermistor
R5T* Domestic hot water tank thermistor
R6T* External indoor or outdoor ambient thermistor
Outdoor R1T Ambient air thermistor
R2T Discharge pipe thermistor
R3T Suction pipe thermistor
R4T Heat exchanger thermistor
R5T Intermediate heat exchanger thermistor
R6T Liquid pipe thermistor
R10T Power module fin thermistor ERHQ V3* / ERLQ V3*
R7T Power module fin thermistor ERHQ W1* / ERLQ W1*
Step Action
1
Disconnect the thermistor from the PCB.
2
Read the temperature and the resistor value.
3
Check if the measured values correspond with the values in the table on the next pages.