A potty question

[Deleted member 26715]

Check the floor around the toilet you may have a leak in the porcelain

 

[Pale Rider]

Check the floor around the toilet you may have a leak in the porcelain

The water drops in both toilets - one in the bathroom, the other at the far end of the 'van in the main bedroom.

Evaporation in winter with the lids on the toilets seems unlikely to me, so I suspect the water is slowly draining through the waste pipe, although it's not meant to.

 

[twentysix by twentyfive]

U bend leaky?

 

[raleighnut]

Its caused by the wind blowing over the end of a vertical 'stench' pipe, this causes a vacuum in the system and pulls the water out of the U-bend and over the 'weir' at the back of the bend

 

[Pale Rider]

Its caused by the wind blowing over the end of a vertical 'stench' pipe, this causes a vacuum in the system and pulls the water out of the U-bend and over the 'weir' at the back of the bend

I can follow that.

Strange that it didn't happen for about six years.

I think there is a pipe on the roof which has a cone shaped lid on it.

That could be a stench pipe, perhaps the lid has shifted, altering the air flow in some way.

 

[ayceejay]

Also check that there is an unblocked vent in the system. We had a problem with a blocked vent so that when we flushed the toilet this would suck the U bend in the sink and bath dry. So I am thinking that (if not this) something is siphoning the water out.

 

[sight-pin]

I don't know the set up for caravans, but with two wc's, if their is no stack pipe you normally expect to have an AAV (automatic air vent) fitted, if this stops working efficiently it can cause a vacuum from outside to suck the water down.

 

[Pale Rider]

Also check that there is an unblocked vent in the system. We had a problem with a blocked vent so that when we flushed the toilet this would suck the U bend in the sink and bath dry. So I am thinking that (if not this) something is siphoning the water out.

Thanks, something else to have a look at.

 

[Pale Rider]

I don't know the set up for caravans, but with two wc's, if their is no stack pipe you normally expect to have an AAV (automatic air vent) fitted, if this stops working efficiently it can cause a vacuum from outside to suck the water down.

What might an AAV look like or where might I find it?

 

[sight-pin]

It will be on the 4" waste by the side of one loo i would suspect, it will be an additional pipe rising with a valve on top

 

[sight-pin]

Maybe it'll be rising through the roof? i really don't know about caravan set up though

 

[oldfatfool]

Check the fall pipe under the 'van. If it is anything like ours it traverses the full width and half the length of the van and the ties holding it at the correct angle often stretch, it is possible the slope on the pipe is the reason your U bend is loosing water, of course the other alternative is a poor seal and a slow leak.

 

[Pale Rider]

It will be on the 4" waste by the side of one loo i would suspect, it will be an additional pipe rising with a valve on top

Ta, I don't recall seeing anything like that, but have never looked specifically, so one could be there.

 

[sight-pin]

Maybe you could google the schematics of your van? it may show something. but with two loo's you will need something to stop one sucking the other etc

Edit, That's assuming they go into the same line

 

[Pale Rider]

Check the fall pipe under the 'van. If it is anything like ours it traverses the full width and half the length of the van and the ties holding it at the correct angle often stretch, it is possible the slope on the pipe is the reason your U bend is loosing water, of course the other alternative is a poor seal and a slow leak.

Yes, that's about the look of it underneath.

Both elbows are supported on bricks, but settlement over the years and ties stretching elsewhere could have altered the angle.