Low pressure flap valve would improve SOG, any ideas? (1 Viewer)

[Louisesjpp]

Several weeks into using my SOG, I'm far from happy. When travelling, especially with a fullish cassette, and when parked with a cross wind on the loo side, smells enter the van. The reason is clear: the cassette interior is now connected to the van exterior by the SOG tube, and so if the outside pressure exceeds the inside pressure, air will be forced from the cassette past the silicone seals into the van. Those seals are watertight, but they're never going to be airtight.

The SOG hose needs a light flap valve fitting so that air can only flow out of it, and not into it.

Question 1: is there such a valve fitted already, and mine is faulty, which is why nine out ten users when questioned say they love their SOGS, or,

Question 2, does anyone know of any little light plastic flap valve which might do the job?

 

[denisejoe]

There is a bung that goes over where the tube exits the holding tank use it when emptying or when moving with more than a 1/4 of a tank as contents can flow up tube

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[BusyBuilder]

A small piece of rubber over the end should work

 

[denisejoe]

Sorry reading it again you probably need a new seal on the cassette as we never get the smell in the van

 

[DBK]

Several weeks into using my SOG, I'm far from happy. When travelling, especially with a fullish cassette, and when parked with a cross wind on the loo side, smells enter the van. The reason is clear: the cassette interior is now connected to the van exterior by the SOG tube, and so if the outside pressure exceeds the inside pressure, air will be forced from the cassette past the silicone seals into the van. Those seals are watertight, but they're never going to be airtight.

The SOG hose needs a light flap valve fitting so that air can only flow out of it, and not into it.

Question 1: is there such a valve fitted already, and mine is faulty, which is why nine out ten users when questioned say they love their SOGS, or,

Question 2, does anyone know of any little light plastic flap valve which might do the job?

What you describe should never happen. I suggest checking the flap seal first. With the flap closed run some water into the bowl and see what happens. If the water drains away the seal probably needs replacing but you could try silicon grease first.

Then try replacing the charcoal filter. Finally, always add a drop of bio laundry liquid to the cassette after emptying.

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[BouncyBoatFolk]

In fixed building plumbing a "Durgo ; aka as an air admittance valve " would be used to allow air into, but not fluids out , but I don't think such a device would work on a SOG. If the outside pressure against the flap exceeded the fan pressure it'll vent to the next easiest resistance, which would probably be the cassette seals
Mike.

 

[L' Hobo]

Sog toilets should be emptied ever day unless using additives.

My slider valve is air tight, my outside charcoal filter stops draughts from the outside and every time I open the slider flap, the fan draw any smell outside.

As has been said, perhaps your charcoal filter needs changing?

 

[Pausim]

I don’t think there would be sufficient pressure to force air through the toilet seal. My cassette also has a vent which automatically opens when the cassette is inserted, it vents through a tube to the top of the cassette and then back down and out of the bottom inside the enclosure. This is a far more likely source of the smalls escaping and this vent can be disabled. It is unwise to disable the vent without providing an alternative pressure release but a SOG does this so I have disconnected the automatic vent on my cassette.

 

[Riverbankannie]

Check the seal around the cassette door as per these fitting instructions

 

[Lenny HB]

The only time I have had smells in the van is when the vent tube has split.
As DBK says check your cassette seal, if you pour water in the bowl it should stay there for several days.

I converted my SOG to a roof vent it works far better.

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[Millcourt]

What you describe should never happen. I suggest checking the flap seal first. With the flap closed run some water into the bowl and see what happens. If the water drains away the seal probably needs replacing but you could try silicon grease first.

Then try replacing the charcoal filter. Finally, always add a drop of bio laundry liquid to the cassette after emptying.

What is the reason for adding bio laundry liquid, as you recommend? When I was at the SOG factory in Germany last year, they were insistent that nothing should be added.

Sog toilets should be emptied ever day unless using additives.

My slider valve is air tight, my outside charcoal filter stops draughts from the outside and every time I open the slider flap, the fan draw any smell outside.

As has been said, perhaps your charcoal filter needs changing?

Not sure why you need to empty every day…..but you may well need to if you use “additives”.


In a similar thread a couple of weeks ago on this topic, I added two postings explaining the advice I was given at the SOG factory. Based on my experience of using my SOG as recommended by the manufacturer over the last 12 months, we are smell free. If interested……have a look at https://www.motorhomefun.co.uk/forum/threads/sog-toilet-any-additives.290631/page-2#post-5791004 …… posts number 33 and 37.

 

[Lenny HB]

What is the reason for adding bio laundry liquid, as you recommend? When I was at the SOG factory in Germany last year, they were insistent that nothing should be added.

We have had SOG's in vans since 2008 never added anything.

 

[Millcourt]

We have had SOG's in vans since 2008 never added anything.

Err….no, Lenny. It was not me wot said it. It was DBK . You are, of course wise in never adding anything.

 

[Just smiffy]

If your cassette seal is ok I suspect the smell is coming from your grey tank, while driving the small traps can let air from the tank pass through or the trap dries out…

The main reason for smells in a van on here will be from the grey tank…

 

[Pausim]

A picture to help explain how smells can escape from the cassette. When the cassette is inserted in the enclosure the rod at the top of the picture which is normally in the tube and attached to the rocker arm, is pushed up and opens the valve at the other end of the rocker. This allows air pressure to escape from the cassette.

If the wind is blowing against a SOG vent in the compartment door there is a possibility the air will blow back into the cassette, out of the open valve and down the tube into the cassette enclosure. From there it can get back into the motorhome.

The valve is necessary to stop pressure building up in the cassette. Use the loo at the bottom of a mountain and then drive up to the top of a pass and you might get a nasty surprise if there is a pressure difference. The SOG provides an alternative vent so I felt safe disabling the Thetford vent. My problem was not smells because we have a roof vented SOG. However I did find some smelly leakage in the cassette enclosure pit after travelling with a full cassette and decided to eliminate the this vent route. I would not have done so without there being an alternative vent through the SOG.

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[L' Hobo]

What is the reason for adding bio laundry liquid, as you recommend? When I was at the SOG factory in Germany last year, they were insistent that nothing should be added.


Not sure why you need to empty every day…..but you may well need to if you use “additives”.


In a similar thread a couple of weeks ago on this topic, I added two postings explaining the advice I was given at the SOG factory. Based on my experience of using my SOG as recommended by the manufacturer over the last 12 months, we are smell free. If interested……have a look at https://www.motorhomefun.co.uk/forum/threads/sog-toilet-any-additives.290631/page-2#post-5791004 …… posts number 33 and 37.

NO, you don't have to empty it every day, (I thought that was what SOG recommended) but after using it to defficate, after a few days in hot weather.....as the saying goes, 'yer pays yer money and makes yer choice!'

 

[Flairy]

Had our sog 22years on this one 7 years on our Hymer never a smell wouldn’t be without it hate going into vans with toilet fluid horrible

 

[AdrianChen]

The only time I have had smells in the van is when the vent tube has split.
As DBK says check your cassette seal, if you pour water in the bowl it should stay there for several days.

I converted my SOG to a roof vent it works far better.

Our E Line had a SOG roof vent - worked really well, no niffs at all.

 

[Russell's Dad]

Not sure why the OP is getting whiffs in the van when the loo is closed.
Further to the other posts re smells, additives and daily emptying. We use no additives, empty when possible but rarely every day and have found that opening the trap for a few seconds before opening the toilet lid makes sure the whiff goes out the roof for my neighbours to enjoy, and does not upset my own nostrils.

 

[Pugwash52]

Several weeks into using my SOG, I'm far from happy. When travelling, especially with a fullish cassette, and when parked with a cross wind on the loo side, smells enter the van. The reason is clear: the cassette interior is now connected to the van exterior by the SOG tube, and so if the outside pressure exceeds the inside pressure, air will be forced from the cassette past the silicone seals into the van. Those seals are watertight, but they're never going to be airtight.

The SOG hose needs a light flap valve fitting so that air can only flow out of it, and not into it.

Question 1: is there such a valve fitted already, and mine is faulty, which is why nine out ten users when questioned say they love their SOGS, or,

Question 2, does anyone know of any little light plastic flap valve which might do the job?

On the floor of the cassette cavity there is a square plastic panel (about 6" square in old money) which is removable lift it up and it unclips. The filter to goes under this when a Thetford extraction system is fitted. When in place, on top of this panel is a small "handle" which acts as a cam and when the cassette is inserted this cam lifts the cassette pressure release valve which you will see on the bottom of the cassette when it's removed. It's a grey plastic "cross-shaped" thing which you can lift with your finger. If a SOG is fitted to the system you then effectively have two vents on the cassette and fumes can (and will) backflow from the outside SOG vent, through the cassette, out of the pressure relief valve and out into the interior of the van - which you will smell. Remove this square panel and the problem will go away. SOG need to emphasis this in their fitting instructions.

Hope that helps,
Pugwash.

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[DBK]

On the floor of the cassette cavity there is a square plastic panel (about 6" square in old money) which is removable lift it up and it unclips. The filter to goes under this when a Thetford extraction system is fitted. When in place, on top of this panel is a small "handle" which acts as a cam and when the cassette is inserted this cam lifts the cassette pressure release valve which you will see on the bottom of the cassette when it's removed. It's a grey plastic "cross-shaped" thing which you can lift with your finger. If a SOG is fitted to the system you then effectively have two vents on the cassette and fumes can (and will) backflow from the outside SOG vent, through the cassette, out of the pressure relief valve and out into the interior of the van - which you will smell. Remove this square panel and the problem will go away. SOG need to emphasis this in their fitting instructions.

Hope that helps,
Pugwash.

You are not describing a SOG system.

But it's an old thread. I guess the OP was driving with a full cassette and the "contents" of the cassette flooded the filter and this was what they were smelling.

 

[Pugwash52]

You are not describing a SOG system.

But it's an old thread. I guess the OP was driving with a full cassette and the "contents" of the cassette flooded the filter and this was what they were smelling.

Hi

You are not describing a SOG system.

But it's an old thread. I guess the OP was driving with a full cassette and the "contents" of the cassette flooded the filter and this was what they were smelling.

"You are not describing a SOG system"
Not sure I understand your comment? I've had several SOGs in several different vans over the last twenty years and I've also fitted many. My comment fits all of the through-door ventilating SOGs which are still currently available and in common use. I realise there are different versions for different toilet installations and also more than one venting option but my
description fits the majority of them. Have I misunderstood something?

I don’t think there would be sufficient pressure to force air through the toilet seal. My cassette also has a vent which automatically opens when the cassette is inserted, it vents through a tube to the top of the cassette and then back down and out of the bottom inside the enclosure. This is a far more likely source of the smalls escaping and this vent can be disabled. It is unwise to disable the vent without providing an alternative pressure release but a SOG does this so I have disconnected the automatic vent on my cassette.

Disabling the cassette vent as you describe when a SOG is fitted is essential otherwise the backflow of smells will definitely occur.

 

[BouncyBoatFolk]

So, should the plastic cover below the cassette be removed when no SOG is fitted, thus closing the breather vent on the cassette?
Mike.

 

[Pugwash52]

So, should the plastic cover below the cassette be removed when no SOG is fitted, thus closing the breather vent on the cassette?
Mike.

No. The original Thetford vent is there to allow the air pressure inside the cassette to always equal the constantly changing atmospheric pressure. If there is no SOG then it's important this vent is open when the cassette is installed. Pausim has a good explanation of this further up this thread.

 

[Maxieras]

A small piece of rubber over the end should work

I was told that when I was younger.

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[Pausim]

No. The original Thetford vent is there to allow the air pressure inside the cassette to always equal the constantly changing atmospheric pressure. If there is no SOG then it's important this vent is open when the cassette is installed. Pausim has a good explanation of this further up this thread.

I read in another place that a non-SOG user had created a new breather pipe so that he could close off the Thetford vent because he was getting smells inside the van. He put a nipple in the cassette end cap and attached a small tube that vented outside.

 

[BusyBuilder]

When we bought our Hymer, we couldn't understand why the toilet was so smelly even with a SOG. I took it to bits and it all looked okay, but when I re fitted it all it worked perfectly....no smell, at all.
I think the wires were reversed at the fan (in the door) so the fan was sucking instead of blowing, and I had inadvertently reversed them again ??

Still think the SOG is a good improvement.