"Cassette Full" light always on.

Remus
Remus Forum Participant Posts: 132
edited August 2016 in Caravans #1

The heading says it all.  The light is on even when the cassette is empty.  Any suggestions as to why?  I can't see anything snagging the float.  The cassette is part of a Thetford 250 toilet.  Any advice would be appreciated.

Comments

  • Cornersteady
    Cornersteady Club Member Posts: 14,436 ✭✭✭
    5,000 Likes 1000 Comments Name Dropper Photogenic
    edited August 2016 #2

    this happened to me, the float contains a magnet which when its floats up to the top must cause some electrical contact and hence the light come on. On mine the float arm would not go back down after emtpying and I had to physically push the float down each time. Yours might be doing the same?

    After a while the float broke off anyway. I always used to empty the cassette every third day anyway so I don't get caught out with the light coming on in the middle of the night. Hope this helps

  • Pathfinder
    Pathfinder Forum Participant Posts: 4,446
    1000 Comments
    edited August 2016 #3

    Either the float is stuck in the up position OR the reed switch is stuck

  • Cornersteady
    Cornersteady Club Member Posts: 14,436 ✭✭✭
    5,000 Likes 1000 Comments Name Dropper Photogenic
    edited August 2016 #4

    take the battery out to stop the light?

  • DougS
    DougS Forum Participant Posts: 327
    edited August 2016 #5

    The magnet activates a reed switch contained just in front of the float position in the housing.

    You can test it by putting a magnet near the reed switch housing with the cassette out.

    https://en.wikipedia.org/wiki/Reed_switch

    If the light goes off when the cassette is out then the reed switch may be OK and the float may be stuck in the full position?

  • Remus
    Remus Forum Participant Posts: 132
    edited August 2016 #6

    Thanks for the replies.  The situation so far is that the float seems to be moving freely.  Removing the cassette and putting a magnet against the reed switch turns the light out.  Could the switch be faulty?  I removed the switch circuit bosrd recently as the terminals were furred up (this was when the flush ceased to work due to a furred fuse as it happens).  I cleaned the terminals on the switch circuit and put it back.  

  • bandgirl
    bandgirl Forum Participant Posts: 440
    100 Comments
    edited August 2016 #7

    The same happened to us as we were setting off for a CL last year. A bit of a worry when you're relying on your own facilities for two weeks. The light was on when the holding tank was empty, but it worked OK, however, a quick swill around the tank with
    some water solved the problem. Can only surmise that there must have been a bit of paper stuck on whatever sensor or bit of equipment in the tank causes the light to work. Could be something as simple as that.Undecided

  • IanH
    IanH Forum Participant Posts: 4,708
    1000 Comments
    edited August 2016 #8

    I don't think our light has worked since the day we got the caravan.

    We just take a look while the flap is open, to see if it's full.

    Take the battery out, would be my advice.

  • EasyT
    EasyT Forum Participant Posts: 16,194
    1000 Comments
    edited August 2016 #9

    I never rely on the light either Ian although it does work

  • Nuggy
    Nuggy Forum Participant Posts: 512
    edited August 2016 #10

    I don't think our light has worked since the day we got the caravan.

    We just take a look while the flap is open, to see if it's full.

    Take the battery out, would be my advice.

    Write your comments here...I thought the power supply was from the leisure battery, has it got it's own battery? I have never seen our light work, may be that's why. Where is it and what is the type?

  • Cornersteady
    Cornersteady Club Member Posts: 14,436 ✭✭✭
    5,000 Likes 1000 Comments Name Dropper Photogenic
    edited August 2016 #11

    a 9v one pp3, mines to the side of the cassette

  • Remus
    Remus Forum Participant Posts: 132
    edited August 2016 #12

    After various fiddling about the light is now out.  I shall leave things alone now as the cassette gets emptied regularly and I doubt it will ever get near to full.  Incidentally, out light is operated from the caravan system, there is no battery to be removed.
     Thanks all for your input.

  • jennyc
    jennyc Forum Participant Posts: 957
    500 Comments
    edited August 2016 #13

    Thanks for the replies.  The situation so far is that the float seems to be moving freely.  Removing the cassette and putting a magnet against the reed switch turns the light out.  Could the switch be faulty?  I removed the switch circuit bosrd recently
    as the terminals were furred up (this was when the flush ceased to work due to a furred fuse as it happens).  I cleaned the terminals on the switch circuit and put it back.  

    Write your comments here...

    Surely the reed switch should close when close to a magnet - that's how they work - A closed switch will switch on the light in a simple circuit. If a magnet switches your light "off" then there's something very wrong with the circuit board.

  • Pippah45
    Pippah45 Forum Participant Posts: 2,452
    1000 Comments
    edited August 2016 #14

    I gave up on the "full light" about 2 years ago - my Thetford has been somewhat of a nightmare - but now I KNOW its not my fault that it used to overflow into the locker whatever I did - I am not bothered by a warning light not working.  (The reason it dirtied
    the locker was that the two halves of the cassette had become unsealed - as far as I know not my fault - but it happened!  And those lockers are not made for such overflows!  Thetford - however assures me that they are changing their lockers to make them more
    "spill" friendly!) 

    Bring back the old manual flush - say I - and do we really need a warning that its full?  So much technology equals unnecessary room for malfunction - to me. 

  • Fysherman
    Fysherman Forum Participant Posts: 1,570
    1000 Comments
    edited August 2016 #15

    I like my electric flush but agree why would anyone need a LED to inform that is geting full?

    Unless perhaps they close the blade by balancing on one foot using the other to move the lever.Laughing

     

  • kentman
    kentman Forum Participant Posts: 147
    edited August 2016 #16

    Have had this problem from time to time on two vans. Has always been due to toilet paper stuck in the float mechanism, sometimes impossible to see without unscrewing the top off the cassette