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Thetford Cassettte Warning Light

Ray

By Ray
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Ray Rising Star

Ray

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Without getting into the usual dispute over the benefit(s) of one type of toilet over another "please", can someone advise whether the warning light electrical circuit on a C262 cassette needs to remain powered at all times when a cassette is attached to the toilet - i.e. the sensor requires continuous power, or whether turning the power off when the boat is vacated shouldn't affect the sensor.

 

The last cassette filled without the light coming on.

 

Thanks.

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BargeeSpud Rising Star

BargeeSpud

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Mine only comes on when it's on the verge of overflow, so I never bother with it & judge how full the cassette is by sight.

 

To answer your original question, it doesn't matter whether the power is turned off when you leave the boat. As soon as you switch it back on, the sensor should work normally, it won't be that sensitive to power outs & it won't make any difference whether a cassette is attached or not. Probably cuts out when you remove the cassette anyway.

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Guest

Guest

Posted
Posted

Without getting into the usual dispute over the benefit(s) of one type of toilet over another "please", can someone advise whether the warning light electrical circuit on a C262 cassette needs to remain powered at all times when a cassette is attached to the toilet - i.e. the sensor requires continuous power, or whether turning the power off when the boat is vacated shouldn't affect the sensor.

 

The last cassette filled without the light coming on.

 

Thanks.

 

There is a known issue with the C250 when the sensor within the tank that activates the switch becomes dislodged and fails to activate the LED. It's caused by over zealous shaking of the tank - could be the same issue although not the same model.

 

It is possible to put it back in place but you need to get your hand inside the tank to do it.

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Thewatchmaker Collaborator

Thewatchmaker

Posted
Posted (edited)

Without getting into the usual dispute over the benefit(s) of one type of toilet over another "please", can someone advise whether the warning light electrical circuit on a C262 cassette needs to remain powered at all times when a cassette is attached to the toilet - i.e. the sensor requires continuous power, or whether turning the power off when the boat is vacated shouldn't affect the sensor.

 

The last cassette filled without the light coming on.

 

Thanks.

 

These work by a float in the tank having a magnet attached that activates a reed switch within the toilet body.

The reed switches often fail.

They are available on eBay are easy to replace

Edited by Thewatchmaker
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Ace 01 Collaborator

Ace 01

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Mine was the same, so we take a look and empty when it is nearly full.

 

Steve

 

 

Same here, we have three tanks in total and only one has the light working.

 

 

Ann

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rjasmith Rising Star

rjasmithDonate to Canal World

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Posted (edited)

I think another possibility for faulty full indication is the allegedly cheap and nasty LED warning light that Thetford fit. This is an LED plus series current limiting resistor as a combined package. If/when mine fails it will get replaced with a discrete LED and resistor which will then limit future failures to sticking cassette mechanisms. Interesting that there are reports of faulty reed switches though. I would have thought they'd be bomb proof!

 

Richard

Edited by rjasmith
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alan_fincher Veteran II

alan_fincher

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There is a known issue with the C250 when the sensor within the tank that activates the switch becomes dislodged and fails to activate the LED. It's caused by over zealous shaking of the tank - could be the same issue although not the same model.

 

It is possible to put it back in place but you need to get your hand inside the tank to do it.

 

And if you don't know what you are doing it is equally possible to smash the arm with the magnet on off completely, instead of achieving the miracle remedy you were hoping for.

 

But please don't ask me how I know this........

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Guest

Guest

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And if you don't know what you are doing it is equally possible to smash the arm with the magnet on off completely, instead of achieving the miracle remedy you were hoping for.

 

But please don't ask me how I know this........

 

Oh dear....

 

 

 

I must admit the main reason I haven't got around to attempting a fix on ours is that it is easy to tell by sight just how full the cassette is. I always find the one of ours that does work a little pessimistic about how much room is left anyway.

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Albion Influencer

Albion

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This cassette tank looks just like the ones that I have repaired on our 250 in the past as far as I can tell. It is almost guaranteed to be the float with the magnet having become dislodged through over-vigorous incorrect shaking during emptying and flushing. After removing the cover slide and unclipping the two sliding cover guide cover strips (make a note of which fits where and the matching arrows) you will see about six (or maybe 8) self tapping cross head screws beneath the cover and round the seal retainer. Undo all these and remove the slide retainers, seal retainer and rubber seal. Reach inside and feel where there is a rectangular shallow bulge on the side of the tank (upper half) and you will almost certainly feel that the float, pivoting at one end, has dropped down and is hanging almost vertically. If this is the case then the float has become dislodged. Rotate the float upwards towards the top of the tank and you should feel it gently click over a spigot and then it should not flop downwards at all but be retained approximately horizontally at its lowest point of rotation. Reassemble in the reverse order. When this first happened I rang Thetford and they recommended doing the rinse slosh by leaning over the top of the cassette tank and rotating the tank in a sort of 10 past to 20 past the clock motion rather than sloshing end to end which is what causes the float to dislodge. I must have rectified three or four of these by now and this has always been the problem.

Roger

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Ray Rising Star

Ray

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Many thanks for comments and suggestions. If push comes to shove we can manage without the light.

 

We've been having trouble with the boat's power supply being left on when the boat is empty and other items not switched off either, thus running the batteries down - it is a common user charity boat.

 

It may be that the master switch for the toilet has been switched off and not switched back on, I need to check that. I shall also check the other cassette when it is next full to see if that demonstrates the same problem.

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alan_fincher Veteran II

alan_fincher

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It may be that the master switch for the toilet has been switched off and not switched back on, I need to check that. I shall also check the other cassette when it is next full to see if that demonstrates the same problem.

Of course if it is a plumbed in model with an electric valve to operate the flush, if that is working, then there should also be 12 volt power to the "red light" circuitry.

 

Whatever has failed in ours isn't the "over centre magnet" in the cassette problem, I think, as even a brand new cassette failed to activate the red light.

 

Based on previous answers, if not the cassette, then both a failed microswitch and the suspect arrangements for the LED seem to be possibilities, and I guess only by pulling things apart can you find out.

 

Of course one doesn't typically have the red light on a stand alone loo, and I can't say I much miss it on the built in one, (which is why I have not expended effort trying to make it work again!....)

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MtB Veteran II

MtBDonate to Canal World

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Posted

Blimey what's wrong with looking down the hole to see if it is full?

 

Reminds me of that thread were the boaters assumed the Nene was safe to cruise because they didn't get a text from the EA warning of flood conditions. Never mind the speed of the river crashing past beneath their hull....

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Ray Rising Star

Ray

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It is a charity boat used as a moveable base for children's play activities.

 

Unfortunately it is extremely difficult to get people to follow some basic instructions with regard to isolation of the supply when they leave the boat. They probably wouldn't even know what a cassette style loo is. The chances of them checking through the flap - some users may actually be children - either before or after using the loo are pretty slim so they're simply told that they mustn't use the loo if the red (holding tank is full) light is on and report the fact to their team leader.

 

This week the light wasn't on (but I've now found out that the supply was) when I routinely checked to see the status so I shall await the next time a cassette is nearly full - yours truly is usually responsible for changing/emptying the cassettes - I shall gradually top it up with water until either it is full (or as good as) or the light comes on. I will then repeat the exercise in due course when the cassettes are swapped next time with that cassette - the one for which the light didn't work this time.

 

However, the boat is all but laid up for the winter so both tests are liable to be in early - mid 2013.

 

Once again, thanks for the comments/suggestions.

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Phil Ambrose Veteran II

Phil Ambrose

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Posted

These work by a float in the tank having a magnet attached that activates a reed switch within the toilet body.

The reed switches often fail.

They are available on eBay are easy to replace

[/

 

Check your reed switch first by simply placing a magnet next to the switch, doing this should cause the light to illuminate, if light comes on it is most likely the float switch inside the casette.

 

Phil

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