Dishwasher - float sensor issue?

[jP]

Any advice from the dishwasher knowledgeable will be appreciated.

In short: My dishwasher often will take a fill of water in preparation for a wash or rinse period, and immeduately drain it rather than run the actual wash or rinse.

All other behaviour is normal. It can drain and dry, for example, and if it managed to actually enter a wash or rinse cycle rather than immeduately drain, that works.

Diagnostics / repair attempts:

After checking the float sensor, which seemed to be working, I figured the timer was defective. I replaced the timer with a rebuilt one, which did not solve the issue. It continued to behave the same.

Opening it immediately after a fill period, I could see it was getting water, but I thought it might not be getting quite enough, prior to the wash/rinse *attempt.

Therefore, I pulled the inlet valve off and cleaned it out. There was a little bit of sand in there that might have slightly restricted the flow.

After putting all back together, it is still not washing/rinsing at the appropriate times -- it just decides to fill-then-drain quote often lot, which wastes water and doesn't clean anything.

• The float sensor should just indicate to the machine to stop taking on water, but could it also tell the machine to simply drain rather than to wash with not enough water?

[PopRivet]

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Doubt it. Assuming the control you replaced also contained all the relays, about all that's left are the solenoids themselves and maybe pinched wires somewhere?

Try manually turning the timer knob and listen/watch each cycle - try to determine what comes on when that shouldn't, then track it back to see if you can find anything. Or, maybe wifey'd like a brand now one? A chance to be a hero? :-) Far's I know, all the float sensor does is shut off the water in case too much flows in.

Give these guys a try: Saved my bacon once (literally; it was a gas stove)!

[Dan O.]

Posting the appliance's brand name and the unit's complete model number is necessary so we can see what design of dishwasher you're dealing with (they're not all the same). You can find tips for locating the model and serial number tag *on your appliances* in the 'Repair Parts' section of my site linked below.

JFYI

Dan O.

- Appliance411.com

=Ð~~~~~~

[jeff]

Hi,

Make, model#, approx age of the d/w??

Flaot normally just helps to shut off the power to the fill valve to prevent over fills/floods.

jeff. Appliance Repair Aid

[Dave Harnish]

Hi,

Are you sure the drain hose isn't too low, allowing water to siphon out? I see this a lot. If there's no high loop - at least as high as the underside of the countertop - and no air gap, then this is a very good possibility.

A brand/model would be a great help, though. From your earlier post I assume it's an analog timer, and not an electronic control.

The float switch is basically just an overfill sensor.

Hope that $.02 worth is of some help.

God bless,

Dave Harnish Dave's Repair Service New Albany, PA

[e-mail]

570-363-2404

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Exodus 20:11

[jP]

Folks, thanks for the feedback.

The dishwasher is about 5 years old. It is a Magic Chef model DU2500V. Analog timer, which as I mentioned, was replaced.

I am very perplexed by this behaviour. It seems that there is very little room for any logic in such an analog system, and that the float sensor is only capable of overriding the timer on a fill -- that should be the only function. So, I guess the machine is incapable of "deciding" to drain if there isn't enough water available due to possible inadequate water pressure.

So...thanks for the general agreement that the float sensor can't be it. The timer was replaced, so that can't be the issue either.

I looked at the operation of the system as it was running a cycle. It looks like the draining action is controlled by a device is actuated by a coil, pulling a short level to actually move what looks like a plastic piston. I have a theory on what might be happening, and I'd like your comments.

It looks like the same pump is responsible for both the pressurized draining as well as the washing. Perhaps, if the drain valve is stuck open for a cycle, the pump will just eject the water out to the drain hose for the entire length of a wash cycle. If the solenoid manages to close it, then you get an occasional wash cycle. Is that likely the root of my problem?

The dishwasher never seems to incorrectly wash when it should be draining. So if my theory is sound, then that must mean the value only gets occasionally stuck in the "drain" position, and not in the "wash" position.

Thanks again in advance for any feedback!

-- jP

[jeff]

Hi,

This d/w has the sideways motor and pump assy with a drain valve and solenoid. These are nasty for broken plastic parts on the drain valve and it will prematurly drain the water out....might even fill and drain at the smae time.

the linkage inside the pump assy and outside on the drain valve/solenoid.

jeff. Appliance Repair Aid

[jP]

Jeff, thanks. Grrr...it figures that I'm stuck with a poorly engineered design. I'll pull off the pump assembly and see if any broken parts are causing this problem. It is is just the drain-solenoid & parts that have a problem, I can afford the $20 for that. But I'm not going to drop $180 on a new pump assembly and motor...better put that $$ into a new machine!

Thanks for the help all. I'll let you know how it works out.

-- jP

[matsen]

I'm having the exact same problem with my GE dishwasher. It'll start filling and just when there's enough water to activate the wash arms, it'll start draining. Replaced the timer also w/o a change. I'd like to know if you changed the solenoid and if that helped. I too would like to avoid paying for a new pump/motor part.

-Dave

[jeff]

Hi,

Check to make sure the drain solenoid and it's plunger are not stuck together holding the drain valve open, lost/missing/broken return spring on the solenoid may also do this, gookus holding the drain valve open can prematurly drain the water out as well, low drain hose ( no high loop ) as well.

jeff. Appliance Repair Aid