Toilet flushing force
We have a new toilet in the basement we just remodeled and the height of the toilet waste line is very close to the height of the main sewer line going out to the street, maybe a few inches. The toilet works fine but is a little slow to finish the flush. I'm wondering if this is due to there being very little slope to the sewer line. For example, would this same toilet flush stronger from our bathroom on the second floor? Thanks. Rob
My opinion would be that it's "doubtful", unless there is an obstruction in your waste line.
Assuming that this is a gravity toilet, the siphon that accomplishes (and completes) your flush is a function of the trapway design, which is molded into the china of your toilet. As long as the waste has somewhere to go once it is pulled through the trapway and falls into the closet bend, and I presume you have the standard slope per foot on your waste line, that's not going to "slow down" the finish of the flush. Neither is improper venting likely to affect what you see happening in the bowl itself.
When toilets swirl and swirl and go down slowly, that's often an indication that you're not getting a good siphon. On old AS toilets, this can happen if the siphon jet hole is blocked, for example. Also, if there's an obstruction in the trapway, this can prevent a complete flush. If this is a new toilet, this could be a function of a defective or poorly-designed trapway, but more likely defective and/or blocked than just "poorly-designed", unless it's some kind of economy model from the Big Box store.
Hard to say much more without more info about the actual installation...
Hope this helps.
(Lucky for you, you live in an area served by one of the greatest plumbers in the country...)
Normally, code wants at least 1/4" per foot of slope in the waste drain pipe. While it can be less if the pipe is at least 4" in diameter, it's good to try to maintain at least the 1/4" per foot. A couple of inches only gives you maybe 8' of run at the proper slope at maybe 16' at the worst case. If the pipe has any flat areas or dips, it will produce problems continually. Without knowing more, it's hard to say if that installation would ever work right in the long term.
It is possible that the line is "holding water" which would slow down the flush at the end, but that is a problem with the drain lines, and possibly a partial stoppage, not the toilet.