I established my pump had died after first checking the fuse seating and good clean contact at the rear of the cassette locker and then testing power to the circuit board under the flush button and also power to the pump when pressing flush.
I have the blue Truma un-clip model pump that's accessed from the cassette locker (some other models have the pump under the flush button on the top of the toilet). Unlike the instructions I found on the internet, I couldn't get my pump to drop down so I couldn't release the hoses and wiring. So I had to remove the toilet from the caravan.
On removing the toilet I discovered that although there was ample power cable to the pump (white in the pics), the slack had been taped up along with the circuit board power cable (black & red in the pics). Pulling the pump down further to release it would have resulted in me yanking the wires out of the circuit board which is located up under the flush button.
Note, if you're that lucky to unclip in situ, note that you push the two blue tabs out-over so the catches release inside. When the toilet is removed, the pump simply slides out sideways.
Caravan power turned off before starting.
Removing the toilet (if the same model as mine in pics) is straightforward. On the outside of the caravan, remove the four screws from the flush filler hatch and also remove the four screws in the base of the waste locker (remove the cassette first). The hatch/locker doors remain in place, as does the sealant, so nothing to worry about here. Once these two sets of four screws are removed, the toilet pulls away from the wall inside the caravan. Note, there may be power cables running along the bottom-rear of the toilet on the caravan floor. The toilet power cable will need unclipping so you can remove the toilet fully from the caravan. Ensure you reconnect this plug when reinstalling the toilet and also ensure any floor wires are not trapped when you replace the toilet in position. When offered back up to the wall, the toilet should sit flush (no pun!) all round the rear edges, with no wires trapped when you look from inside and outside of the caravan.
Wiring in the new pump means cutting the power cable on the old pump. If you cut close'ish to the old pump you'll have ample slack. The new pump has a short lead with crimps already attached. Bear off the now cut wire coming down from the top of the toilet and feed into the crimps (matching up the colours) and then crimp up or use pliers to achieve the same. Check the wires are connected with a gentle pull. When the toilet is still loose in the caravan, it's worth connecting up the power lead, adding the waste cassette and putting some clean water in the cistern for a test flush to confirm the new pump is ok and the various pipes are connected ok and water tight. Remember to turn the caravan power back on for this test to avoid unnecessary heartache...
Thanks for that, I’m sure it’ll be very helpful to someone.
Thankfully, our flush pump is under the flush button on the top of the toilet, so it was much easier to change (after establishing the blades were jammed & wouldn’t free up). Meanwhile, we flushed the toilet with a swirl of water & dettol from a jug.
That looks rather like a CWE250 similar to mine. I had the misfortune of having to replace the pump because it was split by frost damage. I see that yours still has the U-shaped pipe loop under the pump where water never fully drains away. Thetford have a modificated additional drain hose to rectify the problem. They were free from them 10+ years ago but they can also be purchased. See this link.
Dave.
------------- Never argue with an idiot, they will drag you down to their level and beat you on experience.
Mark Twain.
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Topic: When a Truma Toilet Pump Won`t Unclip
via mobile 27/7/2024 at 8:37am
