Thetford C250 Toilet

[DaveA1]

Hi
I seem to have no power to my toilet. It started when I noticed the full light was switching on and off with no input from us. in fact the cassette was empty, changed the reed switch now nothing, not even flushing. I've cleaned every fuse I can fine, gleaming like new pins, still nothing. I'm going to remove the flush pump to see if it's seized. It was working fine on our last trip. I must be missing a fuse somewhere, I've checked the one in the cassette compartment and the one in the fuse box, any more hidden away I've missed. Thanks

 

[WoodlandsCamper]

Do you have an Owner's Handbook containing wiring diagrams? That might help to point you in the right direction (excuse the pun).

 

[DaveA1]

Do you have an Owner's Handbook containing wiring diagrams? That might help to point you in the right direction (excuse the pun).

Thanks WC manuals did not come with van, I'm the second owner.

 

[WoodlandsCamper]

Not sure the age of your van, but does this help?

 

[Dustydog]

Dave
Whilst you have cleaned the fuse have you cleaned the fuse socket?
The fuse socket at the tear of the cassette compartment is notorious for corrosion. Get some electric contact spray and clean the socket.
Use a multimeter and check if power is now flowing.
Good luck.

 

[DaveA1]

Not sure the age of your van, but does this help?

Thanks WC
Had already looked, about as clear as mud.

 

[chrisn7]

Dave
Whilst you have cleaned the fuse have you cleaned the fuse socket?
The fuse socket at the tear of the cassette compartment is notorious for corrosion. Get some electric contact spray and clean the socket.
Use a multimeter and check if power is now flowing.
Good luck.

On the C250, there isn't a socket as such. Instead, the fuse blades press into a pair of spring terminals crimped to their respective wires. These are complicated little beasts, which are best replaced if corroded, as they are almost impossible to clean fully. The reed switch is there only to activate the 'full' warning lamp.Once the fuse, its terminals and reed switch have been sorted, that's it for the cassette compartment. However, I would place an inverted small plastic over the tower containing these components to protect them from any mishaps from up above.
The next place will be inside, and the flush panel on top of the toilet, as these are known failure points too.

https://www.youtube.com/watch?v=YBNAv-n8ghQ&feature=youtu.be
The following covers all toilets, just scroll to find the C250:
https://www.campshop.nl/dbdocs/attachment_20.pdf

 

[Hutch]

I don't know if this may help.
But if we stop, and use the toilet, the loo does't flush. But if I unpug the van from the car, it flushes.

 

[WoodlandsCamper]

That's because the relay inhibits all 12v systems in the van other than fridge and battery charging, whilst being towed.

 

[SirRogerFFS]

Depending on which caravan you have the C250 runs straight off the battery so that should rule one problem out.Again depending on which van you have the The Micro switch does operate the flush pump.I had a similar problem if your circuit board on the top has a removable loom take it off and give the block a quick squirt of WD 40 replace the teminal block and remove a couple of time just clean the terminals in the block this could well do the job . Good luck .
Sir Roger.You can also give a very short burst of wd 40 onto the micro switch but just a a quick one .

 

[DaveA1]

Thanks all, will let you know which cure or cures work.

P S MY van is in my signature.

 

[Rodone]

Try wiggling the power supply 'plug' at the top left of the PC board and /or spray with a drop of electrical contact spray To repeat what I have said before on this forum,the design of pretty well all Thetford electric caravan loo' s are a joke. As they seem to supply all of the van brands, we are stuck with their overcomplicated, badly thought out rubbish, and you should consider any repair to be a temporary one, as my experience is that it will reoccur

 

[chrisn7]

Depending on which caravan you have the C250 runs straight off the battery so that should rule one problem out.Again depending on which van you have the The Micro switch does operate the flush pump.I had a similar problem if your circuit board on the top has a removable loom take it off and give the block a quick squirt of WD 40 replace the teminal block and remove a couple of time just clean the terminals in the block this could well do the job . Good luck .
Sir Roger.You can also give a very short burst of wd 40 onto the micro switch but just a a quick one .

The OP has a Swift, who specifically say not to use WD40, due to its effect on some plastics - it would also leave a residue, which is not what you want in switches. Switch contact cleaner for switches, and Ambersil 40+ for similar lubrication/protection properties to WD40

 

[Damian]

Just to echo the last comment.
WD40 has NO PLACE whatsoever anywhere near a caravan.
It is a water dispersant and is only any good for getting rust off rusty sawblades.
It is the death knell to many of the plastics and wiring in a caravan,

 

[SirRogerFFS]

Damian under normal circumstances I would agree with 100% I only used a miniscule amount on the circuit board connector block and micro switch which cured my problem. I wasnt for one minute suggesting drowning it .or even getting it anywhere else within the caravan . Anyway I m not trying to cause an argument just my findings.
Regards Sir Roger.

 

[Dustydog]

Hi Sir Roger
Don't beat yourself up
WD40 has a place in my caravan toolkit , mainly for stiff locks. It is well documented that polycarbonate type plastics and WD40 don't mix. In fact I don't think pcbs like it.I find a good quality electric contact spray ideal for all those pathetic Thetford electrics.Also I like Plus Gas for releasing seized nuts bolts etc.I find it penetrates better.
The weird thing is though WD40 was developed for the NASA space programme.
I wonder what they used it for

 

[WoodlandsCamper]

Didn't like my own joke - so removed it.

 

[martindf3]

On my van with the same toilet .Flush failed I got my test light out cheap one for cars extended the lead to reach the van battery and traced it (Fuse connection and circuit board corroded and the reed switch stuck on ) I soldered up the board and left reed switch in stuck position so I we can see flush button in the dark . If you have 12v then clip the extended lead into earth wire ,then that tests earth return as well .they do suffer from corrosion around that area. I haven't had to go to the pump yet ,but there is info on internet if you have to . Warning make sure you don't stick test light near mains circuits

 

[Dustydog]

Didn't like my own joke - so removed it.

Hop you're not depressed

 

[Hutch]

Bet you were going to say "Flash in the pan".

 

[WoodlandsCamper]

No, it was to do with WD standing Waste Disposal.

 

[Dustydog]

No, it was to do with WD standing Waste Disposal.

He's going potty

 

[DaveA1]

Thanks for all you replies/help. Electric contact cleaner sorted it, for how long???

 

[SirRogerFFS]

I know I will get shot down for this and as you know I did mine with a minute spray of WD40 over two years ago. I do believe its in a bit of a bad spot for condensation so its impossible to say how long. Thanks for letting us know the end result always nice to hear how it all ends up .
Sir Roger

 

[WoodlandsCamper]

WD40 Contact Cleaner