HELP! Dishwasher - do I need a new sequence switch?
Posted 03 June 2005 - 05:21 PM
- I verified the drain hose is unclogged/unkinked.
- I replaced the piston & nut assembly (check valve) because the rubber plunger was practically disintegrated.
- I replaced the black rubber flapper check valve because it broke and was jammed in one of the hoses.
However, it still won't drain at the very end of the cycle. The DW runs through the cycle from the start, and I can hear it drain properly at various stages as it's supposed to. When it gets to the very end of the cycle, the aux. drain pump is supposed to run for a minute or so, but it doesn't. After about a minute, the drain pump kicks on for literally a second, and shuts off, and then the "Clean" light comes on.
I found a pamphlet in the back of the DW that explained how to run the DW through a diagnostic test cycle using the front panel buttons to advance through various stages. When I do this, and it gets to the drain stage, it drains fine.
I assume the "sequence switch" controls what happens, when, and for how long. If the drain pump works, but consistently doesn't turn on at the same place (end of cycle), is it safe to conclude that the sequence switch is bad?
Posted 04 June 2005 - 08:18 AM
For service manuals and lots of other goodies, become an Apprentice ==> Apprenticeship
Posted 04 June 2005 - 01:32 PM
Posted 04 June 2005 - 06:51 PM
I'm having the exact same problem as you. Mine's a GE GSD5940D01SS. I've pulled the hose, checked all of the outlet ports, checked the flapper valve and check valve - all is good. It will pump out with good flow during the wash events, but will not pump at the end. Nor will it pump out if I abort a wash. I've put a voltmeter on the pump wiring and verified what I felt from the pump - the same as you, it operates only for a second on the end rinse pump out.
I just replaced the switch panel controller (picked up one on ebay for $10.00) and have opened the sequence switch to see if the contacts were good. They are. But it sounds like the sequence switch motor is being activated too soon, rotating the disk away from the pump out command. I can't figure out if there is something that would tell the sequencer to move out of position.
I do not have the phamphlet that you found - wish I did.
Posted 05 June 2005 - 04:21 AM
I ordered a sequence switch, should have by the end of the week. My thinking is the sequence switch tells the control switch WHEN and HOW LONG to do things. We shall see.
Posted 06 June 2005 - 02:43 AM
My thinking was the controller and that the sequencer motor was being pulsed to the correct setting by it. I may take the sequencer back apart and see if I can clean the contacts.
When you take the door apart, if it's like mine, noted the fine thread sheet metal screws go to the second down locations on both sides of the door. Also, after removing the black and white connectors and releasing the harness from it's catch, there are two screws that hold the sequencer in place. Before lifting the sequecer from the middle facing side, hold down the spring loaded white lever that sits under it. The lever operates the soap cover, and rides on the sequencer drum. But if you dont hold it down, it can pop out of place along with the spring. Then you have to figure out how it goes back together.
Posted 06 June 2005 - 03:17 AM
For service manuals and lots of other goodies, become an Apprentice ==> Apprenticeship
Posted 06 June 2005 - 01:13 PM
Thanks. Maybe I'll open the sequencing timer and look at the keys/steps in that again.
I just ran the F1 control test and the one thing that I noted was that when the test was in step 6, the main pump did not remove any water (Remove water with main pump and turn drain solenoid on for 10 sec.), but the test did use the auxiliary pump to get out the water fine at step 12 (Open vent, turn on auxiliary pump for 60 sec.).
Is it possible that the dishwasher relys on the main pump for most of the draining, and the auxiliary pump really should not be doing that much in the end of the cycle?
Posted 08 June 2005 - 01:45 PM
Last week when I discovered the little rubber flapper valve had broken and become lodged in the drain hose, I removed it. I ordered a new one, but in the meantime, used the dishwasher, and continued to have problems with water draining. The only way I could drain was to run the F1 test and let the aux. pump drain everything out at the end.
Well, tonight I installed a new flapper valve ($13 for about 29 cents worth of rubber). NOW THE DW WORKS! It is now draining at the appropriate intervals.
Jack, I think you hit the nail on the head - the main pump seems to do the bulk of the draining, and the aux. pump kicks in at the very end. Without the flapper valve, the main pump was probably just cycling the water around instead of draining it. The flapper apparently prevents that.
If this turns out to be the solution, I'll be VERY happy.
Posted 08 June 2005 - 03:18 PM
I just did our favorite thing, played with the diswasher. I pulled the sequencing timer out and took it apart. I looked over all the contacts again, inspected the timing wheel and found no distortion or wear. Took a whole group of macro photos of all the parts, but maybe I don't need to post all that.
Bottom line, when ohming the contacts as you move the wheel through it's steps, no undo resistance. Cleaned the contacts anyway and put it back in. Still the same, aux pump only but no main pump.
Would you have the part number of that valve? I'll get one and replace the one in there. If it's the one oI'm thinking of, I've replace it about 2.5 years ago.
Posted 08 June 2005 - 03:43 PM
This is located on the out port of the little aux. pump. Definitely replace it, it's a cheesy little thing that doesn't last real long.
My DW did a perfect wash afterward, draining as required, and a complete drain at the end. Problem solved.
Posted 08 June 2005 - 03:48 PM
May take that back - I think I looked at the one under the hex cover located here:
Posted 09 June 2005 - 02:04 PM
EDIT: OK, I just answered my own question, there are two of them.
Posted 09 June 2005 - 04:15 PM
I think the flow logic is that if the main pump does not pump any water after spraying, it would be the flapper valve at the aux pump or the plunger. If the aux pump does not flow, it the flapper in the picture above.
For now I'm thinking that the plunger only effects the main pump, but it might effect both main and aux.
In order to get that flapper in the picture, I believe you have to order the entire chamber noted. It's really not that much - I think I paid $8 for it. But the flapper is just not available by itself.
Posted 10 June 2005 - 05:39 PM
Today I got my first care package, and unfortunately I did not read your message before this. I picked up another chamber body along with the black flapper valve you noted. Pulled the diswasher out and replaced the black flapper valve. The original was missing the center flapper and the only remaining section was the ring. After just replacing that valve, the diswasher runs perfect. Man, I wish I remembered that valve when I did my inspection two weeks ago.
On Monday two more of those black valves will be arrieving as backups, but unfortunately I'm going to Baton Rouge to do some work and won't be home until the end of the week. When I get back, I'll pull the chamber valve out and take a picture of the valves togther so you can see them. I just don't think they are the same.
I can't believe that they could have not put a ball check valve in the hose line in place of the rubber flapper. The right design would have the same flow rate and more durable. It would have only added about $3 to the build cost and this issue would not have happened.
Edit - I just took the aux pump valve image window and sized it so it was small, but the valve was still shown. Then took the picture of the chamber I posted and brought the two together. The aux pump valve is designed so the outer retention ring fits over the pump's outer port in a retaining groove. The chamber's valve's ring does not have as wide a space between the flapper and itself. I believe it's design as a gasket between the body and retension nut.
Posted 11 June 2005 - 07:16 AM
Posted 11 June 2005 - 10:53 AM
Here is where I need help; where is the flapper valve located? (I'm an electrical engineer, not mechanical!) I went to repairclinic.com and they indicated that they thought it might be the piston valve assembly or the check valve. I don't know where these are either.
Are the pumps underneath the arm? How do you remove it? Brute force? Help!
Posted 11 June 2005 - 11:27 AM
Underneath the DW is the main pump, but there's also a smaller auxilliary pump (pictured in link below). It is on the right side of the DW, and you'll see two small wires attached to it. There are two hoses on the aux. pump, the flapper valve is on port for the larger one hose. That port has threads/ridges, which you can see in the picture.:
Remove the hose from the aux pump, the hose looks like this:
Once you get the hose off, you should see some or all of the flapper valve, pictured here:
A few points/tips:
- Shut off the elec. breaker before starting
- Have a bowl to catch water, and a helper to dump it - at least a gallon may come out.
NOTE: If the flapper valve is broken, it's likely the broken part is stuck in the hose pictured above - you need to make sure you remove it to avoid clogs/future problems.
Have fun !
Posted 12 June 2005 - 05:52 AM
Kay, I've known electrical engineers who have been better mechanical engineers then ones with a mechanical degree. You may not have had the experience, but just need assistance.
Sears sent the parts I ordered for Sat delivery, so I am able to compare the parts. The parts I ordered from this site arrieved Friday, so for the extra charge from both retailers, this site was quicker. I've taken some pictures and posted them at my webshots site here along with some other steps:
I would have taken more but my work camera ran out of battery, and after playing with this thing for the past 3 weeks, no way was I going to pull it out again. Till next time .....
To sum up .....
With a GE dishwasher, there are several issues that can cause the water to not fully pump out. As we now know, on the newer dishwashers there are two pumps. One is the main pump that has always been there, and an auxiliary pump added by GE after situations where the main pump could not get all the water out due to long drain hoses.
My opinion on the possible (easy) issues are:
Drain hose clogged.
If the drain hose is clogged, there never will be much or any flow out of the dishwasher into the drain or garbage disposal. That is easy to hear and see, and usually the clog is at the smallest part of the drain line - the connection of the disposal or drain. But the unit must be fully removed to replace the drain line altogether.
Solenoid not functioning.
Second easiest one to check. By removing the four screws holding the kick panel, you can look under and see if the solenoid is pulling down the flow direction flapper. This controls the main pump's flow between spraying the pumping the water out. This malfunction will prevent the dishwasher from fully emptying the tub between cycles and at the end of the cycle (models with aux pump). One needs to open the door between one of the various wash or rinse cycles to see if there is water left in the tub. The main pump does not drain water, but the aux pump does, so it seems like it's working OK except for the end.
Auxiliary pump flapper valve broken.
Possible the most common, with this valve broken, when the main pump only is running, water just recycles in the tub until the aux pump kicks in during the drain periods.
Filter valve not functioning.
I had not had this fail, but it the easiest one to check. This will cause the water to just recycle in the tub. Remove the lower rack, remove the screws holding the filter in the bottom back of the tub, and the filter valve unscrews out.
Chamber valve not functioning.
Have not had this fail, but replaced it just in case. This one may prevent any water from draining out. Located behind the dishwasher, it requires dishwasher removal to replace.
If you need to get the water out and the aux pump is working (drain hose not clogged), you can remove the electrical connector on the water valve and let the dishwasher run through a short cycle to pump out. Usually the first two wash cycles does it.
Removing the dishwasher.
After getting the tub water out and turning off the breaker for the electricity to it, first the four screws that hold the kick panel need to be removed. Then check for the type of water connection to the unit. Some are copper tube, which must be disconnected before the dishwasher can come out. But first, the hot water supply needs to be shut off, which may be part of the kitchen sink shut off valve. When removing the connection, the fitting into the valve must be held as the valve cannot withstand the force necessary to undo the connection. Two wrenches, or pliers and wrenches.
With the water line out of the way (I replaced mine with a flexible one long ago), the second issue is if the election wire is long enough to come out with the dishwasher. Otherwise, the wire must be disconnected within the electrical box on the right hand side. Some installations will have wire attached here that just plugs into a wall socket located behind the dishwasher. You can usually tell this if the wire is not the stiffer white romex or armored cable (depending on code).
Next there are two retaining straps that prevent the dishwasher from tilting forward when the door is opened and loaded rack is pulled out that must be detached. These are located at the top of the unit and can been seen when the door is open. It's best to take a piece of masking tape and place it on the edge of the counter top so you can mark where the screw holes are during reinstallation.
Now the dishwasher can come out, but you need to watch out for catching the insulation on the top and sides (some models), and for length of the drain line. The drain line in my experience is usually mong enough. You should also protect the kitchen floor from scrapes by putting cardboard or a towel under the diswasher feet as it is pulled out.
You can deal with the unit two ways, both require some use of towels. If you lay the unit on it's front face do the back is facing up, there can be a good amount of water that still can drain out of the door. Mass quantities of towels are necessary. The second is to tilt it up on a 45° angle so you have easy access, but not so much water. This requires a helper to hold the unit.
At this point the drain hose can be replaced, or the flapper valves checked. I would have a new aux pump flapper valve in hand before getting to this point since you only want to do this once. If you very casutios, you can also have a new chamber valve.
The hose between the aux pump and the chamber as dfosbenner noted is held in place with wire spring clamps. They are great for retaining tension when the rubber hose compresses over time (unlike worm clamps), but without the right specialized pliers are a pain for me. With pliers or vice grips, compress the tabs together and work the hose off the aux pump connection. There should be the flapper valve in place, or the parts of one. The outer ring of the flapper valve fits in the groove of the output nipple, which can be seen in the two views of the aux pump that dfosbenner references above. The hose just slides over all this once the flapper is in place. It's noted on the valve with side faces out. I've seen this valve very distorted on both occasions that I've replaced it, some someone at GE materials group really needs to select a silicon product for this application. The newer version of the Chamber valve is not orange rather then black, so possible it was changes to a different compound.
You can check the chamber valve by removing the hose connection, and removing the cover nut but turning it clockwise with a large wrench or channel locks. That's about it for the back of the dishwasher. As they say in automotive manuals, reassemble in reverse order.
dfosbenner - Please proof this for errors and any corrections or additions I may have missed.
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