I have searched the dishwasher forum for an answer to this problem, but found only one reference to the C4 error code which now stubbornly refuses to clear from my dishwasher. That post (by Donna, 2/22/09), contains some recommendations which have not worked for me, hence this post.

This problem surfaced after I had filled the rinse aid dispenser (which I do monthly). For some reason, what sometimes happens after I do that, is that the dishwasher will foam up (presumably in reaction to an abundance of rinse aid), and spill out the door onto the floor. This time, upon running the first cycle after filling the rinse aid dispenser, the machine went into the C4 error mode, which has never happened before. The C4 error code is supposed to signify "too much water", or similar, but there is NO water in the machine (except in the sump, where it belongs).

I have tried numerous times to do a "clear/reset", but it keeps going back into C4. The only way to stop the code and the machine is to shut off the power to the machine by hitting the breaker.

The dishwasher is circa 1990, and has been relatively trouble-free. About three months ago, I replaced the control board and a GE service tech replaced the plunger assembly. That having cost me about $300, I am not ready to simply buy a new dishwasher; I’m invested in this machine.

I have attempted the following in order to resolve this problem:

1) I removed and inspected the screen in the rear of the dishwasher, and the plunger assembly below it (which is new);

2) I removed the float cover in the left front of the machine, pushed down on the float to make sure it was operating freely (which it was). However, I don’t know if the switch associated with the float is working properly - and don’t know how to "test" that; one recommendation I had was to replace the float switch. Presumably, you can have a float operating freely, but the switch is bad - which could fool the control board into thinking that there is too much water in the machine. Any suggestions or comments on that?

3) I replaced the water inlet valve (last night -phew!). Just prior to doing this, I followed up on a suggestion in this or another forum to turn off the water supply and then run the dishwasher, and that would resolve the C4 error. It did - but just temporarily. When I shut the water supply off, and then turned the power supply on, the dishwasher went into the "PF" mode (Power Failure), which then allowed me to enter the normal dishwasher cycles. I then hit the "rinse cycle" and let the machine run for about a minute. I then reset the machine, because I was wary of running the machine without water, lest it damage the pump or something. I then turned the water on, and then went to run the cycle again, but it went immediately back to the C4 mode. I attempted to get the machine into the dishwashing cycle one more time by turning off the water, etc, but it didn’t work - it only returned the C4 code.

At this point, I said "the heck with it", and went ahead and replaced the water valve - an arduous task. When I powered up the dishwasher again, it went right into the C4 cycle again - NO dice.

So, frankly, I am running out of solutions short of calling an appliance technician. Some of you may be thinking that I have a clogged drain hose, but I’m pretty sure I don’t - I would be getting additional evidence in the form of backed up sinks, etc, and, moreover, I had checked the drain hose about three months ago just prior to the last repair visit.

The only option I can think of is to replace that float switch and see if that does the trick. I'm just taking shots in the dark at this point, so if anyone has some genuine insight into what might be going on, I am all ears. I am entirely open to advice, suggestions, recommendations. :confused:

Have at it!

I believe after all you have done you are down to a bad float switch or a bad control board (which you just replaced). If there is no water in the tub and you are getting that code after all you have done these two things are the only choices. You can check the float switch with an ohmmeter. It should be open if the float is up and closed with the float down. If it is open all the time replace it. hope this helps!

Dishwasher Repair Guide

I thought I fixed it!!:p

Here's what the problem was: Sitting here wondering what to do next, I wondered if I had re-attached the electric leads to the water inlet value properly; had I inadvertently switched them? So I switched the leads, turned the power on, and bang - it went right into the dishwasher cycle mode. I thought I was done.

I turned the power off again, so that I could put the protective shield around the leads, and turned the power back on. Damn - C4 error again.

Beginning to get to my wit's end here....

Okay - let's assume the thing in the left front of the dishwasher is the float switch - it's got three wires: Two are white with a pink stripe, and go to one lead; the other is red and goes to the other lead. The other switch connected to the solenoid has only two wires, and since that is a drain solenoid, I have to assume it is the drain solenoid sensing switch.

I had a little trouble understanding what you were saying, as I am not an electrician, but I read between the lines and here's what I did:

I took one wire off at a time, and then threw the breaker to turn the machine on. In each instance, the machine went into the C4 mode, and would not stop. I used a pair of needle nose pliers to open and close the switch to see if that would have any effect - nothing. I just kept getting the C4 error.

You said to also check the float switch with an ohmeter. I do have such a device, although not well-versed in its use. I turned the dial to check for ohms, then put the test leads on each of the electrical connections to the float switch. When the switch was DOWN (closed), there were numbers displayed the readout (they changed constantly, but there were numbers). When the switch was UP (open), the display read OL - which according to the user's guide means "there is no resistance encountered across the test leads or the measured value exceeds the range you set".

Does this mean the float switch is working?

One more piece of information: When the float switch was fully connected (no leads disconnected), I pushed down on the switch several times to see if that had any effect on the C4 error - it didn't.