Toilet Does Not Always Flush...Why?

I have lived in this house for 5 years and I have a 1.6 gpf toilet. Since I first moved in, it has not flushed consistently. One time it flushes just fine…the next time it does not. It does not seem to matter how much of a “payload” there is in the toilet when it is flushed. The tanks refills properly and empties like it should. When the first flush does not empty fully and it is necessary to give it a second flush, often times the second flush just swirls around but does not go down. Often a third flush is necessary. It is just puzzling why it flushes correctly one time and does not the next.

Any thoughts / suggestions are much appreciated.


how old’s the house?

is this part of an addition or remodel?

basement bathroom, main floor, 2nd story?

any plumbing work been done on your home, b4 or after moving in?

you’de think if it were an issue with the design of the toilet, the problem would be more consistent.

ccbrands1…that’s why it is so puzzling…it does not do it all the time!!!

The house is 7 years old, there has been no remodel or re-do work, it is a sinlge story home on a concrete slab, and there has been no plumbing work since I moved in?

There is an outdoor clean-out within approximately 12 feet of the toilet. Should I try that or would I be wasting my time?

Any other thoughts / suggestions?

Thanks again,


I’m sure others will chime in as the day wears on but I suspect this might be a venting issue. Either an obstructed vent or an improper vent or even a missing vent. Is there a plumbing stack visible on the roof directly above the bathroom?

MRB…Thanks for your reply. I went into the attic and there is NO vent pipe coming up through the ceiling directly over the wall where the toilet is. There is a 2" vent pipe in the attic right at this location and a nearby tub and two vanities are tied into it and it goes up through the roof. If the toilet in question is tied in, it would have to have been run horizontally approximately 3’ along one wall, then 8’ along another wall and the 3’ along another wall to get tied in at one of the vanities. Do you think someone would have done this versus just going straight up through the wall into the attic. It appears to me that they missed tieing it in but I have no way of knowing without tearing out sheetrock.

I hope I did not confuse you.

In South Carolina, the builder is responsible for such items for 12 years but I have no way to prove to them that it is not tied in. (D. R. Horton)

Your thoughts?

Thanks, Homey

Check out this thread on “lazy flushing”.

Homey, no your description is just fine. I dont know the answers to our questions and that’s where one of the more astute plumbing type HI’s here on the board will have to weigh in on the issue. In general though, most everyone’s gonna say “Call a plumber”.

that was my first thought

I do believe you have one of those two flush toilets that was brought out in the USA to try and save water and many have found they did not do as good as they had hoped .
I am not being factious .
Many Americans came to Canada and bought A Canadian toilet to fix the problem .
The Canadian toilet use more water per flush but only need one flush .
I do not know how the new US toilets are .
I have not heard of any Americans coming to Canada for ours any more .
Roy Cooke

right you are.
the 1.6’s dont always perform too well.
lots of people look for the 5 gals.

I recently sold one I ripped from my old bathroom.
mint green - 5 gal - 40 years old - $80

you can get a brand new Crane Toilet-to-Go 1.6 gal for half that.

I put in a new high riser toilet 3 years ago it is a 3.5 us Gal works well
Roy Cooke

Two things usually cause this. The first is the jet hole in the bottom of your toilet may be partially blocked. If you do the, “If it’s yellow, let in mellow. If it’s brown, flush it down” then this is what can happen. The urine that sits in their for a long time will accumulate on the bottom and build up on the jet hole (Happens on urinals all the time). You can chip it away with any sharp object that you can get in there. I usually use a small screw driver.

The second thing is that it could have something in the trap partially blocking it. A small object like a tooth brush or comb can cause this kind of action.

If it’s not the jet hole use a closet auger to clear the toilet. In my eleven years of plumbing I’ve never found a clogged vent though it may act like that if that were the problem.

I’d check the jet hole first. This would be my experienced educated guess. Good luck.

Nothing wrong with your toilet, Roy is right you have a two[2] flush toilet!!
I came home one day with this new toilet from home depot, received a rebate from the CITY OF TORONTO installed it and regretted ever since.Save water my a$$


First You have not posted your location,the 2" vent pipe in attic should penetrate roof with a 3" pipe [cold climates] second, there is no separate vent for toilet,the stack is the vent.

I agree with ron, make sure the jets are not obstructed and scrub the bowl clean. mine only flushed good when I held the handle down during entire flush or added pine oil to bowl just before flush, ( first sign that it was something simple to fix.)

Are you on city plumbing or septic system? Some on septic systems are sluggish when septic system is not in good shape.

I am in Coastal, South Carolina on city water and sewer.

Thanks for all the replies. Keep them coming!


Another problem we find often is the vent on the roof is partially blocked. If the vent collars are made of lead, the installers will fold the lead back down inside the vent. Sometimes they get a little lazy and do not do a good J-O-B and merely fold the top over cutting off the air and preventing proper venting. Finding this has solved the stubborn flush many times. And if that isn’t it, eat more ruffage.

This was around and below cast iron drains. What caused it?



I have 3 identical toilets and only one is requiring multiple flushes.