Water level problems in my toilet pan

[Baz in Brissy]

Can someone offer advice about the following:
Every now and then the water level in the pan of my toilet drops to the point where the water level breaks the water seal in the S bend - how it happens I don't know. There are 3 toilets in the house and this toilet is the last one on the line, the other 2 are downstream and are not effected. There is a vent pipe associated with this toilet plus another vent downstream.
I was once told that the air vent may be blocked and that suction downstream could be emptying the pan - I've checked the vent and it appears fine.

Any other thoughts?

[ozwinner]

I was once told that the air vent may be blocked and that suction downstream could be emptying the pan - I've checked the vent and it appears fine.

Any other thoughts?
That was my first though, are you sure the vent is working ok??

Al :confused:

[PhilMcCrackin]

Lay off the coloxyl with senna!

[Gumby]

For a first post, you've sure picked a good one............good luck.

[outback]

Unacustomed as I am to give a serious reply to a subject just screaming to have the ***** taken out of it. :D Ooops, reflex action.


The only way this can happen is if suction is occuring somewhere downstream, possibly the problem occurs when one of the other toilets is flushed. I would look seriously at the vent.

I have a not disimilar problem occaisionally after periods of extended wet, (hasn't happened for years) we have a septic system and when it gets really wet we get trouble at the absorbtion trench, which works its way back up the line to one of our toilets, with a similar problem to yours.

Look, check and recheck, there is a block somewhere.

***** of a job, but someones gotta do it.

[Baz in Brissy]

thanks for the advice so far - because I was so sure it was the vent pipe I did get a bit extreme at one stage and put a hacksaw cut thru the vent pipe just where it joins the main line and still have the problem.

[DavidG]

We sometimes have the same problem and the vent is fine.

What happens is that when the wind is blowing from a certain direction and the back door is open then the house gets pressurized.

You can hear the vent fans spin up even with the power off.

I have watched the level in the bowl and it goes down and back up with each gust of wind.
Stops if you close the door into the wind or open another door on the opposite side.

Now wait. Some one is going to cr ap on me for this.

[ozwinner]

You could play musical dunnies........:rolleyes:


Al :D

[johnc]

It looks as though your problem is wind in the loo, suggest the fix might just be to lay off the baked beans.

Seriously though we have one pan upstream that does the same, it occurs rarely and hasn't really bothered us but like you I have often wondered what the cause is. I've assumed it was a vent problem and wondered if the plumbing simply has the vent a bit far down the line but can't get at it to find out.

JohnC

[doublejay]

Very occasionally, we have the same problem. My theory is that if there is an 'incomplete' flush, it is possible that there is some paper that hasn't made it completely over the hump so to speak. This paper can act as a wick causing the water to be drawn from the bowl.

Just a theory.

[johnc]

What we need is someone brave enough to stick their hand up the S bend to find out (or is that down the S bend, who gives a s..t really)

[Gumby]

Every now and then I chuck down a full bucket of water to clear the system...........and that's all I intend to say on the subject :D

[journeyman Mick]

Can someone offer advice about the following:
Every now and then the water level in the pan of my toilet drops........

Ya gotta stop the dog drinking out of it! :eek: :p

Mick

[Programmer]

Mick, by the look of your best friend, you speak from experience :eek: ! But I'm digressing. Yep, check out that S bend. Time to roll on the Ansell long gloves. It's not so bad, just look the other way and think you delivering a calf. :D Just think what you might find? So exciting!

[kiwigeo]

Gidday Baz,

I have a carbon copy problem with the two dunnies in my house. House is on a slope and vent is at highest point in the septic system. I thought the problem might be related to wind blowing across the vent creating a venturi effect but so far no real correlation between strong winds and lowering water levels.

An alternative theory - a combination of the perfect seal created by my giant a...e resting on the seat and the hurricane force gaseous emissions from same may be pushing the water out of the bowl and back down the septic line.

[kiwigeo]

Mick, by the look of your best friend, you speak from experience :eek: ! But I'm digressing. Yep, check out that S bend. Time to roll on the Ansell long gloves. It's not so bad, just look the other way and think you delivering a calf. :D Just think what you might find? So exciting!

Reminds me of a friend whos flatmate attempted to flush a chicken down the loo.

[Ashore]

Mick did you check out all the vents, when you cut the top off the vent you did check that it was clear, piece of wire or plumbers friend blower from vacume cleaner etc ... you may also like to try plumbers friend down s bend before venturing in yourself I have seen rearly cheep and nasty ones at Bunnies
As for the air pressure the weight of water surface area in bowl pie r squared on 4 depth of water etc to push
Try the vents on all the toilets if there all ok then look at wind problem or if your house land is pretty flat you can get mild surges in the sewer main that will give the same effect. But these usually effect all the toilets.

[Santalum]

I've noticed a similar phenomena ( sudden lowering of water level in toilet bowl) over the course of my 60 plus years, and have wondered if it is related to atmospheric conditions or moon cycles, by the way no blockage is present, the water always returns to it's normal level within hours.
Interesting subject.

[adrian]

I had the same thing happen with a toilet in my granny flat. The flat was unused for four years and the water level in the pan would fall to the point where it was almost empty. The toilet was at the point closest to the mains. I have always thought that it was caused by a combination of suction from within the pipe and air pressure outside the pipe.
Does the level fall during periods of heavy rain? If so it may be that there are a few houses upstream with their stormwater connected to the sewer.
Maybe someone with plumbing knowledge on the board could confirm whether the design of a stink pipe works as a kind of release valve for suction pressure. Do you have a stink pipe?

[HavinaGo]

Hi,

1) Do you .. or someone else nearer the loo with the level problem .. hear the blup-bloop when the other loo in the house is flushed? Seen that in houses as the first sign of the septic blocking up .. as hinted by others

2) on the "wind causing a pressure difference in the house" theory .. is there an openable window in the loo with a problem? If so, does leaving the window open help? In my mind an open window should help equalise the pressure between the loo room and outside so there should not be the need for the pressure to equalise via the S/P bend.

Good luck

[Iain]

A plumber told me that a fermenting septic will 'burp' and the resulting vacuum will create the problem, he also told me about some homes in Melb, where the appliances run into the sewerage line, will create a venturi effect and suck the bowl empty.
Sorry if this has already been said.

[Ashore]

check out "nothing at all to do with woodwork ....... This just in "
may be your problem




The original point and click interface was a Smith and Wesson.

[barnsey]

I'm not a plumber but have some exposure to hydraulics.

I get that happen at times too I'm on the side of a hill and connected to sewerage as you would probably be being in Brisbane.

It is rare that there are doors and windows closed here and occasionally it seems to happen when things are colder and the air flow is not the usual. But I do say "seems"!! :rolleyes:

I've also seen it happen when a rather solid unit and lots of paper go down there too. Lets face it, if you've had to get the plunger out it happens as well so it's obviously one or the other.

If pushin the button doesn't fix it then it's worth exploring those two elements. If not then it ain't going to hurt anything just keep an eye on it. Sometimes cracked pipes can cause stuff to catch. Some trees can be particularly invasive. There are ways to deal with all of these so research it and give them a try but if it ain't broke don't fix it. :)