Cassette flush DIY
Fixing the Flush!
A caravan DIY project by our very own caravan experts.
Got an issue with your toilet? Not flushing as you would expect it to? Before you rush off to get it fixed, take a look at this project and see if it’s something you can fix yourself!
- Discovering the problem.
- What caused the fuse to blow?
- What caused the pump to seize?
- Step by Step Repair Guide
- About Caravan Magazine
- Buying your first caravan
Discovering the problem.
No flush water
Our first trip this season revealed that my checks had proved incomplete as there was no flush water coming into the cassette toilet and no sound of the pump running.
Fuse was blown
A quick call to the caravan dealer established that the bench cassette toilet fuse was an uncommon 3A purple blade fuse located inside the cassette compartment and could be changed once the cassette was removed. It’s fiddly to get to as it was mounted high up at the back end of the compartment under a small panel at arm’s length from the access door.
My multimeter showed that the fuse had failed, but why? It seemed sensible to check the pump before fitting a new fuse.
What caused the fuse to blow?
Pump had seized
It turned out that the pump had seized, which was causing an overlarge current flow to blow the fuse, thus protecting the pump motor windings. Access to the flush pump is also tricky and you need to reach it from the washroom.
Once repaired, it was refitted with a new fuse and the wiring and connectors carefully checked before running the pump briefly to confirm that no permanent damage had been done.
Same size fuze - always!
It is important always to remember to refit a replacement fuse of the same rating as this will continue to protect the wiring of the pump itself.
What caused the pump to seize?
Algae seized the pump
Returning the pump to its reservoir, I did notice that presumably because I just use fresh water for flushing, the interior of the flush tank was a bit slimy with algae.
I think that it was this that had caused the pump seizure once the tank had been drained for winter and dried out, gluing up the pump innards.
Step by step guide
Here is the complete fix in one simple 3-step guide.
- From the washroom side, gently lever off the white plastic flush lever then the oval plastic control panel beneath it. Put your hand in and find the pump water pipe and follow it down to the submersible pump which dangles in the flush water reservoir.
- Wiggle the pump back up through the access hole and use a small screwdriver to check the free rotation of the pump impeller, which is visible centrally at the bottom of the pump casing. Mine was solid but a few turns with the screwdriver completely freed it.
- The pump fuse is behind the now marked panel in the cassette compartment. A new 3A fuse was fitted and correct operation of the pump was checked before reinstalling it in the flush tank.
Now you’ve completed all the steps, you should have yourself a perfect flush!
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