# Thetford C200 Outside Vent



## teemyob (Nov 22, 2005)

Hello everyone,

We have a leaky C200 Vent on one of our cassettes. Whilst looking for a replacement I notice there is an optional "Outside vent kit" that helps eliminate the build-up of the nasty niffs.

Does anyone have one of these fitted?
Are they any better?
Would I need to fit one to each of our cassettes (we have a spare)?

Trev.


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## pippin (Nov 15, 2007)

Now there's a coincidence!

I have this afternoon just fitted a SOG kit to our C200.

We had been very aware of the whiffs.

During the fitting process I discovered that ours has the external ventilation system fitted.

The holding tank has an opening in the pressure release valve (different style to the non-ventilated type) which mates up with an opening with a rubber flexible seal. That then leads into a black ribbed pipe which disappears vertically down into the base and thence down through the floor of the van by the wheel arch.

During the modification work I discovered that the bit between the rubber seal and the pipe is sealed by a strip of double-sided sticky tape, which was not fully in position. 
The significance of that has only just dawned on me (as I type this reply) it was probably the source of the whiffs!!

Now, here is the interesting bit.

Rather than cut a ruddy great hole (37mm dia) in the locker door and then screw the filter housing on the outside and then seal it all up with Sikawhatnot, why not.......

........use the existing external ventilation pipe?

So, I modified the large diameter (37mm) extract fan housing by attaching (using silicone sealant) a small funnel. The outlet from the funnel is a push-fit into the end of the existing ventilation pipe.

OK, it is somewhat smaller in diameter but it doesn't seem to restrict the air-flow too much.
I shan't even bother with mounting the carbon filter just yet - will see how my system works out first.

Right, this has been a long-winded reply to your request.

For the Thetford you would need to get the small dia pipe down through the floor - might not be easy.

See what the price difference is between the SOG and Thetford.


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## rowley (May 14, 2005)

Do a search on this Forum for Sog and you will find loads of info. You can buy one from Outdoorbits & get your mhf discount.


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## teemyob (Nov 22, 2005)

*Thanks*

Hello,

Thanks pippin, I like long winded replies and yours helps me a lot.

Rowley,

I was not looking for a SOG, I am aware of the kit but think it rather expensive for what it is.

Trev.


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## rowley (May 14, 2005)

Yes it is expensive. However, it can pay for itself as you do not need to buy any additives in the future. I would not be without my Sog.


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## teemyob (Nov 22, 2005)

*SOG*

Hello,

Yes I see what you are saying. Though £90 for

A 12v Fan
Bit of pipe
Plastic cowl moulding
Microswitch
Few other bits

and an instruction leaflet no one seems to understand.

Awful lot of money.

I have a good supply of chemicals at the moment. In the meantime I might try and come up with my own version of the kit.

Trev.


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## spykal (May 9, 2005)

*diy*



teemyob said:


> In the meantime I might try and come up with my own version of the kit.
> 
> Trev.


Hi Trev

Vicdicdoc has already done just that ....see Here << for an interesting thread about how :wink:

Mike


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## Spacerunner (Mar 18, 2006)

pippin said:


> Now there's a coincidence!
> 
> I have this afternoon just fitted a Sog and Thetford.


Are you sure that this is not the dump-while-driving system.publicised by the Caravan Club on 1-4-07?


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## pippin (Nov 15, 2007)

*YCH a FI!!*

Can't quite get the gist of that last post.

Incidentally I had a good firkle about inside the cassette this afternoon.

Yes, I know, not a pleasant subject.

I had forgotten to empty the cassette after our trip away four weeks ago.

Decided to give it a good clean out and then filled it with warm Ariel Bio water.

After emptying it again I decided to rinse it out again and gave it a good whooshing about..

Not a good idea as it dislodged the "full" level float mechanism.

Hence the firkle inside in order to refit the thing.

What surprised, indeed, disgusted me is that the float is some sort of sponge open to the "contents" of the tank.
Not very hygienic.

The downloadable instructions/pictures from Thetford on how to replace various bits inside the tank are very interesting- in a sadistic sort of way.

They are obviously taken using a tank that has not had the bottom half fitted.
Translate that to groping about blindly with ones hand/wrist poked through the blade opening is a totally different kettle of fish.

Not easy!

Still, I know every intimate nook and cranny of the thing now.


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## gaspode (May 9, 2005)

To answer your original question Trev. :roll: 

We have the additional vent fitted (N&B fit them as original equipment) and I would say that it does cut down on odour. It also eliminates the problem of pressure building inside the cassette when changing altitude. I do agree about the Sog pricing, rather over the top for what it is in my view.


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## peejay (May 10, 2005)

teemyob said:


> Would I need to fit one to each of our cassettes (we have a spare)?
> 
> Trev.


Hi Trev, similar reply as Ken, we have one on our Hymer as well.

The only thing I have to add - we have a spare cassette like yourself. In addition to purchasing and fitting the vent kit itself, you will need to replace the vents in the waste tanks from the standard vent as pictured here......










....to the optional exterior vent...










..or just replace one and switch the vents when you swop casettes, its a simple 'twist to remove' operation.

They cost about £11 each.

Pete


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## pippin (Nov 15, 2007)

Ours had the lower of those two pictures.

Had I known I would have saved myself the cost of the S0G and all the faffing about of fitting the vent cap when emptying the cassette.

I would simply have installed a fan into the existing vent pipe fitted by Hymer and let the air be sucked out through the connection with it.

I might even one day retrofit but alas I would have to buy a replacement lever unit for the one that had to be modified to fit the S0G.

Grrrr!


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## vicdicdoc (May 14, 2005)

My DIY version has been working perfectly since day 1 !
http://www.vicfire.zoomshare.com/1.shtml/Toilet Fan Assembly


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