thetford c200 electric flush

Discussion in 'Motorhome Chat' started by dru, Feb 20, 2014.

  1. dru

    dru Read Only Funster

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    Hi guys, have managed to get a space to park the Fiat C.I carioca 1.9TD at home (designated parking) which saves me an 80 mile round trip to storage area - so I'm now just trying to familiarise myself with the bits and bobs fitted. I found the Thetford c200 s/cs wont flush - I have replaced the fuse (badly corroded) and now getting 12 volts at the flush switch, but still no flush. Could anyone tell me how the electrics work on M/Homes - I see there is no built in water tank and presume it gets the flush water from the on board tank and again presume the flush switch when pressed sends a signal to the M/H water pump to switch on. I would be grateful if anybody could tell me what the wires going to the flush switch do and their colours so I can do a bit of troubleshooting with the multi meter. A schematic of the guts of the system and how it comes apart would be a bonus, thanks, dru
    ps tried the Thetford site - chocolate teapot springs to mind, d
     
  2. TheBig1

    TheBig1 Funster Life Member

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    the flush switch sends power to an electric valve....this valve is possibly stuck. you need to measure the voltage at the valve when pressing the button

    sometimes a few taps with the handle of a screwdriver will release a sticky valve


    just a thought, there is water in the tank and the pump is turned on and working? check theres water at the taps first
     
  3. wasp

    wasp Funster

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  4. camocam1

    camocam1 Read Only Funster

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    Make sure pump is actually switched on at theontrol panel
     
  5. mitzimad

    mitzimad Funster

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    if i recall there is the option of using the toilet with either water system presurised or microswitched do you know which you have ?
     
  6. The Wino

    The Wino Funster

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    Suggest you make sure the rest of the water system is working then try again. As I understand it there are 2 types of system. One where the whole system is pressurised when a tap/shower /your loo is used the pressure drop is sensed and the pump runs until the pressure rebuilds when the demand stops (had a problem with this on a boat a few years ago pumped about 100 litres when it heeled over and something knocked the tap on I now make sure the water switch on the control panel is turned off when not in use!!!). IF this is your systom the button on the loo just opens a valve to let the pressurised water out it wont work unless the system is on. The other type of system only switches the pump on when a tap etc is switched on they all have micro switches wired to the pump the pump stops when the taps are closed. If you put water in your main tank and turn off all the taps and the pump starts when the control panel water switch is turned on then stops after a few seconds you have a presurised system ,if nothing happens until a taps turned on a micro switch system if the pump starts and carries on an air or water leak!!!. Im sure someone who knows more will help if there is still a problem but best to try the whole system first before dismantling:thumb:

    David
     
  7. dru

    dru Read Only Funster

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    thetford flush

    Thanks guys for the replies - a lot of good advice there for me to start troubleshooting and will have a go in the morning - re the wire colours at the flush switch I'm hoping I will be able to trace them and they end up at the on board water pump or go to the electric valve. I'll check if the system is pressurised or micro switched and check out the electric valve as suggested by TheBig1 - if I can find it - help on where it lives would be great, thanks again to all for your replies, dru
     
  8. TheBig1

    TheBig1 Funster Life Member

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    [​IMG]

    item 4 on the drawing above......follow the pipe supplying the loo and it ends at a plastic block with wires attached, then continues down to the flush tube. these toilets are not usually wired with a microswitch to trigger the pump, its a pressure system. open the valve and the pressure drops triggering the pump. sometimes the reed switch that detects whether a cassette is in can fail, so check this if no power to the valve

    its a very simple system to troubleshoot. if theres power to the valve but no pump running, then either the pumps off or the valve is stuck. inside the valve is a simple rubber diaphragm and these go sticky after time and fuse themselves to the plastic. on rarer occasions the coil that actuates the valve fails but ive only seen this once.
     
    Last edited: Feb 20, 2014
  9. Bollard

    Bollard Funster

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    Not Flushing

    Had a similar problem. Remove cassette from cupboard. Right at the back there is a small circuit board (not the bigger one behind the push button) . . . You can remove it (bit fiddly) clean and replace the circuit board if necessary. You have to quote the serial number normally on a sticker inside the holding bay as there are several boards for the same model. Nothing is simple is it? Good luck!:shout:
     
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