Jackson MSC JP-24B Service Manual - Service Procedures Continued
SERVICE PROCEDURES continued
A. To remove and replace booster tank.
(1) Drain wash tank by using Off/Drain function.
(2) Disconnect power to machine.
(3) Disconnect water supply line to machine.
(4) Drain booster tank by removing plug from bottom of tank. See Procedure (8) Step (B-5).
WARNING: Booster tank is full of approximately (3) gallons of very hot water. Be extremely careful
when draining.
(5) Disconnect wire leads to heater. See procedure (8), Step (B-5).
(6) Disconnect heater contactor coil wires. CAUTION: Booster heater must be disabled at
contactor (wire lead - orange/white) and dishwasher filled with water in wash sump before power is
reconnected to heater contactor or heater will be damaged.
(7) Remove heater and gasket. See procedure (8), Step (B-5).
(8) Remove booster tank thermostat by loosing mounting nut and remove. Note: Thermostat must
have a new compression ferrel on stem. See procedure (9), step (A-1).
(9) Lay dishwasher onto right-side to remove booster tank. CAUTION: Insure that machine is
properly protected against damage from scratches, dents. -
(10) Remove inlet plumbing to booster tank.
(11) Remove vacuum breaker pipe from booster tank.
(12) Remove and replace booster tank which is secured by (9) locknuts.
(13) Unbolt booster tank from mounting area. NOTE: Factory installed thermal putty may make it
difficult to separate tank from machine. It may be necessary to use pry bar between tank and
machine to remove. Do not remove any thermal putty from surface of wash tank. Install new tank on
same surface using as much of the existing thermal putty as possible.
(14) Reverse procedures to install replacement tank.
B. To test new replacement tank.
(1) Turn on power to machine. WARNING: Do not reconnect heater contactor wire lead (orange/
white) until dishwasher is full of water. See instructions to follow.
(2) Turn on water supply to machine.
(3) Place dishwasher cycle switch in auto position and turn power switch to on/fill position.
(4) VERY IMPORTANT: Run dishwasher through several complete cycles and check water level in
wash sump for correct level. When wash tank is full of water, reconnect wire lead
(orange/white) to the heater contactor coil.
(5) Run dishwasher through several cycles and check for any leaks. Check to see that rinse and
wash temperatures are correct.
11. To install Vacuum Breaker repair kit.
An atmospheric type anti-siphon vacuum breaker is installed in the inlet water line at the back of the
dishwasher before the line enters the machine. This water line provides water pressure for the final rinse
cycle and it is not subject to back pressure or continuous pressure.
The vacuum breaker incorporates an atmospheric vent in combination with a check valve. Its operation
depends on a supply of potable water to seal off the atmospheric vent, admitting the water downstream to
the rinse spray arms. If a negative pressure develops in the supply line, the loss of pressure permits the
check valve to drop sealing the orifice while at the same time the vent opens admitting air to the system to
break vacuum.
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