Bosch dishwasher not draining all the time

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by rbmail, Sep 19, 2008.

  1. rbmail

    rbmail New Member

    Messages:
    5
    I have a 7 year old Bosch diswasher that is not draining all the time.

    I have checked the line from the DW to the drain - which I believe is called a stand pipe and it is free of obstructions. the DW is not connected into the disposal, nor is there an air gap by the sink.

    I have removed the drain pump cover and the impellor moves freely - with some resistance as it rotates the motor past the permanent magnet. I ran the drain pump with the drain hose emptying into a bucket and it produced a good flow.

    So, I am left wondering do I have some obstructions in the stand pipe or down stream drainage? If so, how do I confirm this and then what is the remedy. There is also some kind of fixture on the outside of the house about 6 feet above the drain pipe. It opens to the outside air, and appears to be connected to the drain system.

    Any advice or suggestions?

    Thanks,

    -RB
  2. gfe76

    gfe76 New Member

    Messages:
    88
    Location:
    Florida
    I think I asked this same question on this forum and was told that is the way the Bosch is designed....I verified it with the manufacturer (because I doubted the responses----even though these guys are GREAT to take the time to even respond to us novices!).....Bosch told me you just have to run the dishwasher daily----what a poor design.
  3. rbmail

    rbmail New Member

    Messages:
    5
    We run the d/w at least once a day. I think the recommendation to run it once a day, was to avoid the d/w getting smells from the stagnant water in the drum sump. In any case, it is being run once a day.

    Thanks for the reply.
  4. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    Does it never drain or is the problem intermittant?
  5. rbmail

    rbmail New Member

    Messages:
    5
    It is intermittent. Sometimes we open the d/w and there is still a tub full of water, and sometimes it is drained down below the main filter.

    I can force the drain pump to run and sometimes it will pump out all the water and sometimes it won't.
  6. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    If I had to guess I's say the impeller on the pump is slipping.
  7. rbmail

    rbmail New Member

    Messages:
    5
    any way to test this? I have manually rotated the impellor and it does not feel like it is slipping. Also, when I run the drain pump line into a bucket, the flow is consistent and strong.
  8. 51f1

    51f1 New Member

    Messages:
    3
    Here's what our problem was with a less than year old Bosch. Maybe yours is different, but here goes: It would not drain completely, and all screens, etc in washer bottom were always clear and clean. The problem was in the drain pipe, where it reaches the "air break" on the sinktop. It looks like a giant thimble. I took the top off, and found debris that I removed with a large tweezers/needle nose pliers. The debris was thin silicone discs that came off of some plastic cutting boards bottoms, I guess put there so boards wouldn't slide on the tile top of counters. There were 8 of these "buttons" missing from the cutting boards, and over two weeks, all worked their way into the airbreak chamber, cutting off the air or draining water. Removed them, no problem since. I really don't see how they got past the DW's strainers in bottom of washer, but they all did.
  9. rbmail

    rbmail New Member

    Messages:
    5
    We don't have the air gap, but there is an air vent on the outside of the house (johnson T).
    I went to the clean out located under the sink and snaked the drain line from there. There was a fair a amount of "sludge" right at the top of the clean out, near the cap. After snaking, I ran a garden house into the clean out at full force for a couple minutes to rinse out the line. Repeated this snake a rinse procedure.

    So far we have about 20 washings with no backup.

    The house is about 25 years old, and would like some of the experts to advise if I should get a pro out to assess the overall drainage situation in the home.

    -RB
    Last edited by a moderator: Oct 1, 2008
  10. Terry

    Terry Administrator Staff Member

    Messages:
    15,053
    Location:
    Bothell, Washington
    I like using Bio-Clean for kitchen lines. It helps to clean out the goo that starts building up.


    [​IMG]
    Last edited: May 24, 2014
  11. brendancf

    brendancf New Member

    Messages:
    1
    Bosch shx36L drain won't turn off!

    My drain won't turn off at all. I can turn the washer off, and the drain goes off. As soon as I turn the washer back on, the drain pump starts running again. I can't seem to run any cycles with the washer either, it just tries to drain. The drain did stop working, but I cleaned everything out and it started draining fine. Until we can get the drain pump to turn off though, we can't run a normal wash. Any ideas? Is there some sort of sensor that may be broken?
    thanks!
  12. jpritch2

    jpritch2 New Member

    Messages:
    1
    bosch dishwasher won't drain...

    I had the same problem and it was! the vent on the sink..
    It was clogged up with rice! So I took my shop vac and suck it out good and viola! it works. lol. thanks 51f1!

    jp
  13. abdul

    abdul New Member

    Messages:
    1
    Location:
    Ottawa Canada
    Not draining

    I have disconnected the drain pipe from under the sink and have placed it in a bucket. Still no draining.
    i am a little hazy about the "air gap". Can't seem to find it.
  14. npgibbons

    npgibbons New Member

    Messages:
    1
    Location:
    MA
    Did you ever resolve the drain not shutting off?

    I have a similar issue with an impeller that never seems to stop. The only way to stop it to to kill power to the unit. Was a sensor the issue in your situation. What are causes for an impeller not ever shutting off even when the dishwasher is off?

    Thanks
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