Thetford Cassette Porta-Pottie Won't Flush!!

Discussion in 'Port-A-Potties / Cassette Toilets / Bath Houses' started by malenurse13, Jun 30, 2015.

  1. malenurse13

    malenurse13 New Member

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    I've got an old Thetford Cassette Porta-Pottie in my 1998 StarCraft Spacemaster. I have not been able to flush it for quite some time. I have checked all fuses in the camper and all is well. This is the only electric accessory that does not work. I'm getting no motor sound or anything when I try to flush, so I'm assuming it's an electrical problem. I've got water in the cassette and in the upper chamber where the flush water is supposed to come from. Is there a safety switch to make sure the cassette is installed before allowing the flush? Any ideas how to trouble shoot and find out why it won't flush?? [PU]
     
  2. jjg

    jjg Member

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  3. jjg

    jjg Member

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    If its a Thetford C2 it will also have a fuse on the underneath of the toilet. Have you checked that one yet? One other suggestion is that the pumped may have seized up. You can access the pump if you pull out the plastic bowl that the toilet paper sits in. Take the pump and give the propeller a few turns and see it that frees it.
     
  4. vinmaker

    vinmaker Member

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    I agree. The two things you need to check is the fuse in the toilet and the actual flush pump. The fuses are prone to blow when the pump gets stuck from non use. It happened to me also.

    Not a big deal to replace. Just a bit of patience.

    VIn.
     
  5. malenurse13

    malenurse13 New Member

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    I've replaced the fuse and flasher from the access door on the outside and still no flush. It seems a seized motor is the most common problem with these old cassette toilets. But the flusher knob right by the toilet doesn't seem to want to come off. Does anyone have any tips or tricks on how to access the motor??
     
  6. jjg

    jjg Member

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    Dont remove the flusher knob. To access the pump remove the toilet paper holder. Gently pry it up with a screw driver.
     
  7. malenurse13

    malenurse13 New Member

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    Found it! The pump is not working. I moved the little fan inside (impellar??) and it still won't run. I can feel the motor trying to run while holding it in my hands. But it won't pump. My local parts guy says it'll cost $70 to replace the pump. Has anyone ever tried replacing it with some other pump than the original? Are there any aquarium pumps or something cheaper that might work??
     
  8. bldmtnrider

    bldmtnrider Member

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    Had the same thing happen to mine. I searched long and hard for a 12v water pump and found a few that would work, but most of them still cost ~$40. In light of fixing it correctly, I bought a new Thetford pump off Amazon. Camping World wanted ~90 for it, Amazon had one for 45.

    I think the part number for mine was 33368. Do a google search for "Thetford 33368 water pump" and you should find a few different buying options (of course verify that it is the correct part number).
     
  9. DieselLibertyCRD

    DieselLibertyCRD Member

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    I had the same problem with my C2 Toilet. Pump seized, i hear its common if they are not used for long periods of time. I went with this one, Took about a week to get it from UK to USA.

    http://www.ebay.com/itm/Replacement-Thetford-Cassette-Toilet-Submersible-Flush-Pump-C2-C200-C400-C500-/201189631771?hash=item2ed7d6271b

    I also bypassed the flasher as I read it tends to be a source of problems as well. I have an electronic timer module i want to put in its place but it works fine for now.


    There are these pumps on ebay as well, they look like they would fit but i can not confirm that they do..

    http://www.ebay.com/itm/400831447343?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
     
  10. Rob Roy

    Rob Roy New Member

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    I am in the process of trying to replace my pump. I have the pump in hand, but can't see how to disconnect the electrical wire (in the white insulation). Any help?
     
  11. neighbormike

    neighbormike Well-Known Member

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    I would recommend starting a new thread to get better advice... but I would just cut the wire if there's no connector nearby.
     
  12. SteveP

    SteveP Well-Known Member

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    If you have the Thetford replacement pump it will have short wires with crimp connectors already attached and a piece of shrink tube. Cut the old wire about the same length, slide the shrink tube onto the wire then strip and crimp the old wires into the connecters. Use a hair dryer or heat gun to shrink the tubing, making sure you cover the crimp connectors completely and get a good seal around the wires to prevent shorts through the water.
     
  13. Rob Roy

    Rob Roy New Member

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    Thanks! I did just that, and replaced the fuse above the cartridge, and Ta-Da! It works! Sadly, I had also disassembled much of the linkage and microswitch housing (to confirm that the cassette is in place before enabling the pump). This was completely unnecessary, but reassembling it, with recessed connectors and blindly located screws turned out to be much more difficult than the pump replacement. All good now, though. Thanks again!
     
    neighbormike likes this.

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