I am adding a 1/2 bath in my basement. My setup is as follows:

I had a 4inch PVC sticking out of the floor, where I hooked up a toilet.

Located right behind the 4inch drain was a 2" vent/drain?

I wet vented the sink to this 2"line by making a horizontal connection (with 1/4 inch drop per foot)which is about 3 feet away, with 1 1/2 inch line, from the 2" vertical line in the floor. I extended this vertical piece from the floor vertically to an exterior vent (that was already in place before I started) I also extended the vent pipe above the sink drain about 3 feet vertically and then horizontly back to the 2" vertical vent pipe just described above.

Basically it makes a vertical vent stack with a rectangular drain/vent for the sink to the left. Hope that makes sense ( a picture is worth a thousand words!)

I hooked up the toilet but I have NOT hooked up the sink to the drain yet, has a rag stuffed in it! The toilet water level is low. Questions are as follows:

1) did I configure my pipes the correct way for both the sink and the toilet?

2) My toilet level is low because:

a) the little hose insn't connected to the overflow tube (sorry not at home to check), if not, connect it and try again

b) the toilet is a low flush 1.6 gals, aquaflush and the level is going to be low (should be checked by height of S trap on the back of toilet vs water level, again not at home to check), I guess live with it!

c) the drain/vent for the sink is open causing the low toilet water level, so connect sink drain and see if water level rises

d) the toilet has a small crack, last resort. Dismount the toilet and see if it hold water when not connected.


Is this the order I should check things? Or am I missing something or did I do something wrong?


I found the 1 1/4 to 1 1/2 washer I needed to hook up sink. Is the sink not being hooked up to that drain/vent line that goes with the toilet even a culprit in this?

Is the level of water in the bowl normal after a flush and then drops low after awhile? That little fill hoes must be inserted in the overflow tube. Before a flush how high is the water in the tank compared to the top of the overflow tube? It should be within an inch of the top.

Located right behind the 4inch drain was a 2" vent/drain? Is this line a dry vent fro the toilet or is it draining something from upstairs?
If it's a dry vent your hook up will work.

My toilet level is low
Try (a) first,
Exactly where is the crack you mentioned in (d)?
If it's below the water level then pull the toilet and set the bowl up off the ground.
Fill the bowl with water. If you see any leakage replace the bowl.
Good luck, Tom

I don't know if there is a crack, I am just looking at my options/answers from other questions posted here. And yes the line is a dry vent from the basement floor vertically through the roof.

Ballengerb1
Home Repair & Remodeling Expert





Join Date: Dec 2006
Location: Chicago suburb
Posts: 16,772
Is the level of water in the bowl normal after a flush and then drops low after awhile?

Answer Bobs question to find out if you have a cracked bowl.
Let us know, Tom

Would there be any water on the bathroom floor if it was leaking?

would there be any water on the bathroom floor if it was leaking?

NO! It would go down the drain and not on the floor.

Where would the water leak from when I took it out to check it. Or rather where do I look?

If you do not see a crack at least go back and answer my questions. Many things other than a crack can cause your condition

Checked the following:

1. little hose is in overflow tube

2. water appears to not be higher when first filled. I checked the depth with a wooden stick, it was 4 and 3/4 of an inch from bottom of hole in the bowl and didn't change

3. the water fill line is within a 1/2 inch of the top of overflow tube

4. I did NOT connect my sink to the OPEN drain/vent line yet; wrong pieces (damn 1 1/4 tail piece and 1 1/2 P trap into the wall) (do the make a coupler for that?)

Back at it again tomorrow - glad this is an extra bath!

2. water appears to not be higher when first filled. I checked the depth with a wooden stick, it was 4 and 3/4 of an inch from bottom of hole in the bowl and didn't change
I'm confused! If the water was higher when it first fillked how can you say it hadn't changed?
Did the level drop after it first filled or didn't it? Did it drop down a bit and then just stay there. Please explain. Regards, Tom

Sorry if it sounds confusing. I let the bowl fill up completely. It measured 4 and 3/4" deep to bottom of hole in the bowl. I waited a few minutes and checked it again and the level did not change.

I am leaning toward your possible answer of B "b) the toilet is a low flush 1.6 gals, aquaflush and the level is going to be low (should be checked by height of S trap on the back of toilet vs water level, again not at home to check), I guess live with it!" Ig you never had a 1.6 gpf toilet it may just appear low to you. Some of mine do and some do not. Each manufacturer makes the sump area different.

I was afraid of that. It does flush fine, actually very good. It was rated 4/4 stars for flushing power and high effiecency for water consumption. Are you familiar with the Aquasource brand (Lowes brand)?

I do hear some water filling sound after the bowl is filled, maybe its just a little more going into the tank. Because the water level doesn't seem to change.

If you hear water running after the float has popped shut there could be some leakage around the flapper, check the rim with your thumb