Water Inlet Valves - Maytag Commercial MYR20 Service Manual

The Hot and Cold inlet Valves are mounted
to the top right side of the upper back panel.
The Cold inlet is a four way valve and the Hot
inlet is a three way valve. See Inlets Valve
Chart, below, for Dispenser connections.
Each port will fill at approximately 20 liters per
minute. Valve Coils are 220 VAC.
(See page 4-17) for proper connection of
each water inlet valve.
valve # Water Temp
1 Cold
2 Cold
3 Cold
4 Cold
5 Hot
6 Hot
7 Hot
The inlet valves are designed to operate over
a water pressure range of 30 to 120 pounds
per square inch. Low water pressure and
particularly low flow pressure may result in a
valve not closing properly. Debris in the water
line may also affect operation of the valves.
nOTe: Less than 20 psi, valves may leak.
The first time the washer is hooked up and
the water is turned on, there will be a small
amount of water released through the valve(s)
as the water line pressure builds up behind
the rubber diaphragm(s) in the guide tube of
the valve(s). It is this internal pressure that
keeps the diaphragm seated against the valve
seat and avoids water flow through the valve.

WaTer inLeT vaLveS

Dispenser
PreWash
Main Wash
Bleach
Fabric Softener
PreWash
Main Wash
Bleach
3-2
The water at the inlet (G) pushes against the
diaphragm (H). The solenoid plunger (B) and
the spring (A) by themselves are not strong
enough to overcome the water pressure
trying to raise the diaphragm. Therefore, it is
necessary to equalize the pressure on both
sides of the diaphragm in order to keep the
diaphragm in a closed position. Pressure
builds up in the guide tube above the
diaphragm and keeps it in the closed position.
The flow of water is blocked until the solenoid
is energized. To accomplish this, a small pilot
hole (C) is provided in the diaphragm to allow
water to flow into the plunger area. The water
in the plunger area equalizes the pressure
on both sides of the diaphragm. The spring
pushes the plunger down into the center
hole (D) of the diaphragm and closes it until
the solenoid is energized. To energize the
solenoid an electromagnetic field is created
that pulls the plunger upwards, which opens
the center hole. Water is allowed to escape
through the center hole in the diaphragm,
reducing the pressure in the plunger area.
The pressure from the water supply forces the
diaphragm up and allows the water to pass
under the diaphragm and into the washer.