How To Remove The Booster Heater - Mitsubishi Electric EHST20C-VM6HB Service Manual

DISASSEMBLY PROCEDURE

8. How to remove the booster heater

(1) Remove the front panel. (Refer to Procedure 1.)
(2) Remove the control box cover. (Refer to Procedure 3.)
() Disconnect the CNBHT connector on the controller
board, and the 4 booster heater lead wires wired to the
BHC1 and BHC2 contactors and release the lead wires
from the fastener, the 6 bands and the  cable straps.
(Photos 8-1, 10-1, 10-)
(4) Close (OFF) the pump valve (lower) to stop flow. (Photo
8-)
(5) Remove the two G1" nuts. (Photo 8-3)
w When reinstalling the G1" nuts, use new G1" gaskets.
(6) Hold the top of the booster heater using a pipe wrench
and turn the flare nut using a spanner. (Photo 8-3)
(7) Remove the two screws on the heater stay. Lift the
booster heater slightly and remove the booster heater
from the heater stay. (Photo 8-4)
(8) Remove the drain cock from the booster heater.
(Photo 8-)
w Replace the removed drain cock (primary circuit). The
reused drain cock could cause water leakage.
Photo 8-4
OCH531
Photo 8-1
Controller
board
CNBHT
connector
w The photos shown are of the EHST20C-YM9HB model.
Photo 8-2
Photo 8-3
Booster
heater
75
PHOTOS
Earth leakage circuit
Control box
breakers (ECB1, ECB)
Terminal block (TB1)
Pump valve
handle (lower)
Pump valve
(lower)
Flare nut
Nut (G1")
Gasket (G1")
Screw
Heater stay
Nut (G1")
Screw
Drain cock
Gasket (G1")
Contactors