[cdnron]

I'm trying to help someone fix their older "Quiet Wash Plus" dishwasher. The Model # on the tag is WBU39000...although I can't find anything with that number when I Google it.

It has two problems that may or may not be related.

1) The unit does not fill with enough water. The solenoid valve opens and starts to fill it, but then it shuts before the fill level is high enough to keep the pump primed. The float switch is not what is shutting the valve off. The float switch works because when the valve is open I can manually operate the float limit switch and use it to open/close the solenoid valve.

Once the valve shuts...it stays shut. If I then open the door and manually add about 5-6 quarts of water...the washer works just fine.

2) If I let the unit run through the entire cycle it will not shut off. The timer seems to get stuck at times and will not advance to the next function. Seems like there is not enough spring pressure to move it along.

I'm wondering if the timer is also what is shutting off the solenoid valve prematurely????

Any help you could provide would be appreciated. It's my girlfriend's dishwasher and I'm trying to prove my handiman capabilities to her....

[denman]

I also cannot find any info using that Model Number.
But may be able to help with part of your problem.

1) The unit does not fill with enough water.
The water inlet valve (usually behind the kick plate, left hand side) has a filter screen on it's input side. Could be it is clogged up. Remove the valve and clean/check it. Do not remove the screen from the valve as it is there to keep crud out of the valve which could hold it open and cause a flood.

The float switch is not what is shutting the valve off.
On most units the float switch does not shut off the water. It is there just as a safety device. The time the valve is open is determined just by the timer.


Getting the water level correct may solve the other problem as many units have wait times while the water heats up, if the level is low the water cannot heat properly. Also the water's input temperature should be a minimum of 120 degrees

[cdnron]

So...it sounds from your description that the water level is primarily controlled just by the time the inlet valve is held open by the timer? With the float switch being a "fail safe" feature?

Seems kind of an imprecise way of filling to a consistent level as a change in water pressure would give you a higher or lower fill level.

In any case...I'll check the inlet screen this week and see what I find.

Thanks for the help.

[denman]

So...it sounds from your description that the water level is primarily controlled just by the time the inlet valve is held open by the timer?
Yes

With the float switch being a "fail safe" feature?
Yes

[cdnron]

OK...I shut off the water supply to the washer and took out the inlet solenoid valve. The screen on the inlet side looked like new. No debris or deposits clogging it.

Put it all back together and turned the unit on. Keeping my hand on the inlet valve I could tell when it opened and closed. It opens as soon as the timer is turned to start the cycle and stays open for 2 minutes then you can hear the timer click and feel the valve shut.

I found a timer diagram inside the door when I removed the liner. According to that...the fill cycle should be 2 minutes...so everything looks good on the control side of things as far as I can tell. Unfortunately the actual fill level I get is (at most) 1/2 of what it should be. If I reset the timer to start all over again and initiate two fill cycles, the water level is then high enough for the unit to spray water properly.

The inlet valve should either be fully open or closed...so that leads me to the conclusion that there is not enough water pressure feeding the inlet valve. There is however no lack of water pressure in the sink right next to the dish washer...so that theory is kind of tough to believe.

...but it seems the problem is either not enough water to the valve or not enough water through the valve.

Any other thoughts or suggestions out there ...I'm all ears.

[denman]

I would replace the valve.