REPLACING ELECTRIC WATER PUMP IN THETFORD C/CS TOILET By zappysblog.com The flush on the C/CS models is by an electric submersible pump which sometimes seizes up and will not flush. They can be freed up using a little WD40 but after a couple of times doing this I decided to replace it. The procedure is faily easy but a little care has to be taken due to plastic components becoming brittle and the risk of breaking them. Before starting, make sure the electric supply is isolated; it is only 12v but shorts can cause fuses to blow. 1. Leaver off the top panel which houses the flushing switch it is held by mastic and two plastic pegs underneath so try to lift it off squarely to avoid breaking the pegs. 2. Once off, you will see the inside of the tank and a bracket on the top which has to be removed by unscrewing the four stainless steel screws Plastic Pegs S/S Screws 3. When the bracket is removed the inside of the tank can be seen with the vacuum breaker on the top of the outlet hoses. The left hand hose is from the pump and the right hand hose to the WC bowl. REPLACING ELECTRIC WATER PUMP IN THETFORD C/CS TOILET By zappysblog.com Plastic clips 4. The pump is held in position by two plastic spring clips at the top and bottom of the pump hose which are moulded into the tank wall. Be very careful when prising out the hose from the clips as they can be brittle with age and easily snap off as one of mine did. Fortunately it was the top one and I managed to repair it. The pump can now be removed and the hoses disconnected. Pump 5. Pump with hoses disconnected 6. I got my pump off EBay for under £15. It came with two connectors and waterproof shrink wrapping to protect the connections from water in the tank. The lead was about .5m long to be cut to size. Connectors Shrink wrap REPLACING ELECTRIC WATER PUMP IN THETFORD C/CS TOILET By zappysblog.com 7. The connections into the switch are difficult to remove it is better to cut the cable and join with the connectors provided. 8. Cut the old pump cable as high as possible (to keep joints out of water) 9. Strip the red and blue cables back about a centimetre REPLACING ELECTRIC WATER PUMP IN THETFORD C/CS TOILET By zappysblog.com 10. Thread the new pump cable through the plastic bracket measure the length to where you have cut the old pump cable ready for joining. Thread through plastic bracket. 11. After stripping the ends of the cable feed the heat shrink wrap onto the cable before joining. REPLACING ELECTRIC WATER PUMP IN THETFORD C/CS TOILET By zappysblog.com 12. Push the bared wires into each end of the connectors and crimp with a crimping tool. I prefer soldering but the connectors do the job. Temporarily restore the 12v supply and try the pump before continuing. If the pump fails to work recheck the connections 13. Pull the shrink wrap over the two crimped connectors. 14. With a hair dryer or a heat gun gently heat the shrink wrap until it shrinks tightly over the joints. Don’t overdo it and remember it maybe be hot! REPLACING ELECTRIC WATER PUMP IN THETFORD C/CS TOILET By zappysblog.com 15. Shrink wrap shrunk over the connectors. 16. Re-connect the flushing tube and vacuum breaker and carefully replace the tube to the pump in the clips. 17. The top clip broke off in mine and I had to do a repair. REPLACING ELECTRIC WATER PUMP IN THETFORD C/CS TOILET By zappysblog.com 18. The repair: I took the broken clip, drilled out the shank and inserted a stainless steel self tapping screw. I then glued it to the plastic peg on the tank wall with Gripfill my favourite ‘no-nails type adhesive. Leave for 24 hours and I will be able to use a tie wrap to hold the tube assembly firm. S/S Screw Tie Wrap Plastic Peg Gripfill Adhesive Old clip 19. The tube assembly held firm by the tie wrap around the stainless steel screw. 20. Replace the plastic bracket and the four screws REPLACING ELECTRIC WATER PUMP IN THETFORD C/CS TOILET By zappysblog.com 21. Clean off the old mastic from the cover and replace with non setting mastic strip or adhesive. Don’t forget the cover needs to be removable! 22. Replace the cover and test it out.