I've got a toilet in the basement with an up-flush tank and pump.
After the pump has emptied the tank under the tiolet, the next flush works 100% OK.
From the second or the third flush I get this:
1. Flush fine
2. Water comes back to start filling the bowl
3. But then the water level drops as the water is siphoned out until it gurgles for air.
4. Adding more water to the bowl doesn't help - it keeps on siphoning out but at a slower pace.
5. After 2 or 3 flushes the pump kicks in and then everything is OK again.

When the pump switches on, there is initially a slight suction in the toilet bowl, and as the tank level drops suddenly the water restores to a more normal level and stays stable.

With the bowl on it's lowest level and the tank half full, when I add more water to the tank from the sink, the level in the bowl rises slightly.

I guess it must be a venting problem?
There is a venting pipe on the tank system and no leak or stink on the utility side of the wall where the pump is also located.
There is a bath + basin also in the bathroom.
Occasionally it is so bad that we get sewer gas in the bathroom and have to keep the extraction fan running to prevent the whole basement from stinking.
I phoned BUR-CAM who supplied the pump+tank but they couldn't help at all.

Help much appreciated, please?

More info on my question:
I did check all the vent lines in the utility space.
The basin/sink and the bath/shower each has it's own trap and vent line. The 2 vent lines are connected and vents into the utility space.
The BUR-CAM easy-flush tank is separately vented via a 3" line that is reduced to 2" and vented into the utility space.

Hi Ferdilouw..

As you said, the burcam has a 3" ejector pit vent... usually exits roof by itself but some cities/towns will allow you to connect into the plumbing vents... so hard to believe this is a venting issue, but of course, can't rule out, for sure!

First, I'd chase out the 3" vent and see if that exits the roof and if it does is it clogged by leaves or a bird's nest, etc...

Another thought that is a possibility here is that the installer didn't drill the 5/32" hole required in the discharge pipe (but inside the pit)... this can cause AIR LOCK and can cause issues with the pumping/discharge. On this, I would call BURCAM back and discuss if that hole is required or not. It is required on all other ejector systems that I know of... ;)

Next, and this can be a bit messy, I'd check the CHECK VALVE ASSEMBLY. Here, something may have gotten hung up at the check valve and is causing a back-pressure issue... maybe? If you check this know that there is raw sewage above the check valve so your best bet will be to take the check valve off from the bottom first and then use a stick to jab up at the check valve flapper while having a bucket underneath to catch the sewage. Inspect the flapper and the valve and see if there is anything obvious.

Finally, if all that fails to show you the issue then you will need to lift the toilet and inspect the trapway... sounds like there could be something caught in there... maybe?

That's my approach here. Let me know what you discover, OK?

Questions? Let us know.

Mark

Wow, Mark!
You sure did your homework!

I'll start by chasing the vent. It just goes about 2 feet above the pit and terminates in a 2" pipe with a ventilator.
The sink/basin and shower/bath each has their own vent lines that combine 4 feet up, also with a 2" pipe and a ventilator.
They vent into a utility space behind the wall still in the basement.

Bur Cam do require a vent hole of unspecified size in the discharge pipe. It seems that they supply the discharge pipe with the hole. I'll have to check mine.

The check valve assembly can cause back pressure if things go wrong. My problem is too much sucktion/low pressure in the pit.

If the toilet discharge pipe is extended down into the pit below the high water mark bu above the low water mark, then that might explain my symptoms.
As a last resort I'll lift the toilet, but that is stretching my abilities. :-)

Good info.

Keep us posted... glad to discuss each step as you go along!

Mark

Hi Mark,

I went as far as removing the vent pipe from the pit, leaving it open, and testing.
The vent hole in the discharge pipe works! (Splashed a bit on me!)
The water levels in the pit seems a normal 2 3/4" to 4 1/2" - by my estimates.
But even with the big 3" hole open for ventilation, the toilet bowl still gets sucked to it minimum level once the pit water level rose by 2 flushes.

My logic tells me it can only be caused by the siphoning in the toilet. But why does it depends on the water level in the pit?

Ferdi

First, YUK! Imagine when it's not your own sewage through that vent hole... ;) I've been "SPLASHED" a few times!

Second, my guess at this point (sight unseen) is that something has gotten hung up at the trap of the toilet bowl. Here, capillary action can take place and an object, such as a feminine napkin (or even tooth floss), can get caught in the trapway of the toilet (or at the flange outlet) and literally SIPHON the toilet bowl to a low point in the toilet bowl... allowing sewer gasses to escape!

At this point I'd probably snake the toilet using a CLOSET AUGER (see image... available at any home supplier)... don't send snake more than 3 feet to avoid entering ejector pit, or next, I'd remove the toilet and inspect the trapway/outlet to the toilet bowl and see what may be siphoning the toilet bowl.

Let me know your thoughts here... glad to try to work through this!

Mark

Thanks, Mark.
My wife becomes a little frustrated by my "fix it yourself" failures and forbids me to lift the toilet.
But I'll get an auger and see if it can do anything.

Thanks

Ferdi

Hi Mark massplumber2008

At last I managed to get a plumber to lift the toilet.
My theory that a pipe goes down into the holding tank was correct.
The installer used a floor flange that was some 4" tall, going up to 2" below the water level in the holding tank when the water level was high.
Replaced the flange with a shorter one and the problem is gone!


Thanks for your help
Ferdi

Awesome news, Ferdi. Thank you for taking the time to update the thread. I am sure someone will find this very helpful in the future!

Mark