Waste Water Tank Smell Traps

[alistair]

When the subject of eliminating smells from waste water tanks has been raised in this forum, the most popular solution seems to be adding some sort of deoderiser to the tank. Another option of ensuring nothing fatty goes down the sink doesn't appeal as it requires a discipline I don't have. I'm interested in fitting traps to the four waste water connections (sink, washbasin, shower x2), and feel the HGWT smell traps made by CAK Tanks would be worth a try. They come in two sizes, 20mm and 25mm.

 

Has anyone out there used these traps, and are they effective?

 

I am in New Zealand and our 1998 Autosleeper Duetto is in Dorset, We join it on 31 May for three months touring. If the verdict here is that the traps are worth a try, I would like to have them waiting on me when we collect the van. The problem is that I don't know the size to order (20 or 25mm ID) and won't be able to confirm until we arrive. Without wishing to offend the good people of Dorset, we don't want to stay there waiting on the traps to arrive as France beckons. Does anyone have a middle-aged Duetto or is familiar enough with them to be able to say with some certainty what size the waste water hoses are?

 

All suggestions gratefully received!

 

Thanks.

 

Alistair

[Keithl]

Hi Alistair,

 

We suffered with smells from the kitchen sink and occasionally the washroom basin so I have fitted CAK traps (well only the kitchen sink so far!).

As I could not easily get to a vertical run of waste hose to fit the HGWT type I have fitted a WD1425G in a horizontal run under the floor. This way I can easily reach underneath the MH and remove the bowl from the trap to clean it.

The down side of WD1425G traps is that you need to buy connectors to be able to fit them into a hose as they're designed for fitting in rigid plastic pipes. I used WD1424 adaptors and had to buy some rubber 'end cuffs' from my local caravan accessory store to be able to connect to the grey convoluted hose to complete the job. And you will also need some solvent cement to glue the adaptors into the trap if you use these parts.

 

Definitely worth fitting as no smells since.

Sorry but can't help with AS pipe sizes though I'm afraid.

 

Keith.

[747]

Be aware that just lately, CAK tanks have been quite slow at processing orders. I was kept waiting for well over a week when I recently placed an order. There have been other complaints on forums about this.

[vindiboy]

I would have thought it easier just to put plugs in the sinks ??????????

[alistair]

The Duetto's washbasin in the bathroom is a flip-up type, and access to the plug-hole isn't very convenient as it's at the bottom of the cavity into which the basin folds. For the sake of a few pounds, I would prefer the convenience of a smell trap, and if I'm fitting one, I may as well fit them to all the pipes.

 

I'm also lazy and forgetful and installing a permanent solution that requires no further action from me has some attraction!

 

Alistair

[Tomored]

I fitted these traps and they work, only problem is that the water seems to take longer to drain away. I most certainly would not glue the pipes into place as the traps might need cleaning of old food bits, also one would want to drain them for the winter lay up.

[George Collings]

Hello Alistair.

 

The pipework on my 97 Auto-Sleepers Medallion is 20mm ID. Its a good bet yours will be the same size.

 

Smells are not a problem as the pipe runs under the floor of the Medallion form effective water traps.

 

Space restrictions and poor access may make fitting the CAK traps to the Duetto a nightmare. If smells become a problem it might be easier to buy extra pipe and connectors in France and form the traps in the pipe (laying on your back under the 'van with smelly water dripping in your ear is such fun)

 

There are lots of dealer adverts in French motorcaravan magazines on sale in most supermarkets.

 

Bon voyage

 

 

[alistair]

Thanks for the comments Tom & George. Your thoughts on the size of waste pipework are probably right, George - my memory of them is that they would be around 25mm outside which suggests 20mm inside. Yes, I have some concerns about the practicality of fitting the traps in the Duetto - vertical runs are quite short. I also have wondered about adding extra hose and forming it into S-bends to make traps, but can't check that out until I collect the van. It would give me something to do in France rather than waste time sightseeing and lying in the sun!!

 

Something to think about!

 

Alistair

 

[Brian Kirby]

A couple of ideas. 

First, the smell is mainly from decomposing organic waste, either aerobic or anaerobic.  The worst pong is, generally, from anaerobic decomposition.  I therefore wonder whether the cause could be diminished if, on your last day of using the van, you heated the water heater to full temp, and then pumped the lot to the sink, washbasin and, if you've been using it, shower and into the waste tank, and then drained the tank while the water is still hot.  I have heard that a handful of ordinary washing soda granules dissolved in the sink, and then flushed into the tank and drained is effective against the smell.

Second, I wonder if leaving the waste tank drain open while the van is in storage, and adding a vent for the tank (possibly by inserting to "T" piece into an accessible drain pipe, and extending the branch as high as possible at the rear of the van) to allow some air to circulate through it, would help to keep the tank "sweet".  The problem I can see with the water traps is that while I'm sure they would work while the van is in use, they would dry out while it is in store, to leave the smell accumulating inside the van.  To that extent, they seem more of a prevention than a cure.

[Tomo3090]

I pretty do the same as Brian apart from putting some waste tank cleaning fluid down the plugs before we head for home. Then after the fluid has slopped about during the journey drain the tank completely when I get home. Our tank also has two big openings in the base with screw tops in them, (or should that be bottoms!?) for cleaning it out. I keep promising to get a Karcher lance in there but so far haven't been brave enough to tackle that job!