Operating Procedure - Mitsubishi Electric PUHZ-W85VHA Service Manual

OPERATING PROCEDURE

4. Removing the thermistor <Plate HEX Liquid> (TH6)
(1) Remove the service panel. (See photo 1.)
(2) Remove the top panel. (See photo 1.)
(3) Disconnect the connector TH7/6 (red) on the controller
circuit board.
(4) Loosen the clamps for the lead wire.
(5) Pull out the thermistor <Plate HEX Liquid> (TH6) from
the sensor holder.
Note: In case of replacing thermistor <Plate HEX Liquid>
(TH6), replace it together with thermistor<Outdoor
ambient> (TH7), since they are combined together.
Refer to No.5 below to remove thermistor <Outdoor
ambient>.
5. Removing the thermistor <Outdoor ambient> (TH7)
(1) Remove the service panel. (See photo 1.)
(2) Remove the top panel. (See photo 1.)
(3) Disconnect the connector TH7/6 (red) on the controller
circuit board.
(4) Loosen the clamps for the lead wire.
(5) Pull out the thermistor <Outdoor ambient> (TH7) from
the sensor holder.
Note: In case of replacing thermistor <Outdoor ambient>
(TH7), replace it together with thermistor <Plate HEX
Liquid> (TH6), since they are combined together.
Refer to No.4 above to remove thermistor <Plate HEX
Liquid>.
6. Removing the thermistor <Liquid pipe> (TH3) and
thermistor <Discharge> (TH4)
(1) Remove the service panel. (See photo 1.)
(2) Disconnect the connectors, TH3 (white) and TH4 (white),
on the controller circuit board.
(3) Loosen the clamps for the lead wire.
(4) Pull out the thermistor <Liquid pipe> (TH3) (See photo 5.)
and thermistor <Discharge> (TH4) from the sensor holder.
7. Removing the thermistor <Inlet Water> (TH32)
(1) Remove the service panel. (See photo 1.)
(2) Remove 2 screws (5 x 10) and remove the front cover
panel.
(3) Remove 2 screws (5 x 10) and remove the back cover
panel.
(4) Disconnect the connectors, TH32 (black) on the controller
circuit board.
(5) Loosen the clamp for the lead wire.
(6) Remove the thermistor <Inlet water> (TH32) from the plate
heat exchanger.
Note: Before removing the thermistor<Inlet water> (TH32),
recover water in the plate heat exchanger.
PHOTOS & ILLUSTRATION
Photo 5
Plate HEX liquid
thermistor (TH6)
Receiver
Photo 6
Sensor holder for outdoor ambient thermistor (TH7)
Photo 7
Discharge ther-
mistor (TH4)
Photo 8
Inlet water
thermistor (TH32)
39 39
Outdoor liquid
thermistor (TH3)
Plate heat
exchanger
Plate heat exchanger
fixing screw
Plate heat
exchanger