[Pirate Jenny]

I am trying to install a vintage green Kohler toilet and am having a problem with incomplete flushing. I’m pretty sure the problem is mineral deposits. I can flush the toilet with a bucket. When I flush the tank, the water in the bowl swirls but the level stays the same. I’ve removed some thick deposits from the areas in the bowl that I can reach and, even after leaving a half gallon of vinegar in the bowl for two nights, I can feel that there’s still more. I’ve poked the rim jets with a coat hanger and didn’t notice any blockage there. The siphon hole on this toilet is deep inside at the back of the bowl, barely reachable and impossible to see. I can’t tell if or how much it might be blocked. I might be able to maneuver a flexible tube into it, but a coat hanger would be impossible.

I’m wondering if I’m on the right track with the vinegar. The mineral deposits are almost 1/8 of an inch thick in spots. I don’t mind letting the vinegar sit for as long as it takes, but how long is reasonable? Once the weather warms up, I was thinking of taking the bowl outside, adding the vinegar, sealing the openings with plastic wrap and letting the whole thing kind of steam. I have nothing to lose at this point and I’m not ready to give up on this fun, colorful toilet.

FYI, this toilet originally had an Aqua Vent system which was disabled long before I got it and, I believe, was functional without it. It was also sitting in a garage without a tank lid for quite awhile.

 

[chandler48]

Older toilets required up to 5 gallons per flush. The water level in the tank should be about 5/8" below the top of the overflow tube. If yours isn't, you will need to adjust the float on the valve to allow it to reach that point. Make sure the flapper is new and the chain is installed with just slight amount of slack so it will lift completely.

 

[Pirate Jenny]

For testing, I’m filling the tank high by holding down the float and then flushing by holding the flapper all the way up until all the water flows out. The Aqua Vent contraption conceals the top of the overflow tube and may be impeding the flow of water to the rim jets, so I need to rig up something to bypass that before I know for sure whether my flow is being impeded by obstruction.

 

[chandler48]

Post a picture of your current tank assembly.

 

[GrayHair]

Siphoning is usually started by a siphon jet as shown below.

If the water level in the bowl isn't high enough or the flow into the bowl doesn't keep the level high enough to maintain flow over the high point, the siphoning action will "break".

 

[Pirate Jenny]

Post a picture of your current tank assembly.

The tank is disassembled right now and I’ve removed the Aqua Vent unit to do some testing without it. Here’s a video someone made about Aqua Vent.

 

[GrayHair]

The tank is disassembled right now and I’ve removed the Aqua Vent unit to do some testing without it. Here’s a video someone made about Aqua Vent.

Strange animal! Seems like the manufacturer came up with a solution that never found a problem to answer. Turning on the vent fan seems far simpler than the Aqua Vent.

Edited for clarification.

 

[Pirate Jenny]

Siphoning is usually started by a siphon jet as shown below.

If the water level in the bowl isn't high enough or the flow into the bowl doesn't keep the level high enough to maintain flow over the high point, the siphoning action will "break".
View attachment 739971

Strange animal! Seems like a solution that never found a problem to answer. I would just turn the vent fan on.

I’m not trying to restore the venting, just work around it.

The fill valve I have is not original. I’m not sure about the flush valve. It looks like an ordinary flush valve. The Aqua Vent “box” slides over the overflow tube. If I get rid of the box, I have to plug the hole it fits into in the tank, which I’m happy to do, once I’m convinced this toilet will flush.

 

[GrayHair]

Once I read my post again, I realized it wasn't clear that my comment was addressed to the manufacturer. My sincere apologies.

But it made me think about venting. I'm no plumber, but I've head that a blocked vent can cause water to be drawn out of a trap. Without enough water in the bowl it is difficult to get the siphon started. Hopefully a pro will be along soon with more helpful answers.

 

[GrayHair]

Was hoping someone like @TheEplumber would stop by.

 

[Pirate Jenny]

Had success today. I removed the Aqua Vent mechanism, temporarily plugged the hole it occupied, reassembled the toilet and it worked! I think the overflow tube was being compromised. Now i have to figure out how I want to plug the 1.125 inch hole in the bottom of the tank and get new fill and flush valves. Any ideas on the hole plugging? Sink stopper and silicone? Body filler?

 

[GrayHair]

All I can come up with will involve removing the tank. A solid brass bolt and washers similar to the ones often used to connect the tank to the bowl (shown below). Insert the bolt thru a metal washer, up thru the bottom of the tank, thru a second rubber washer, a brass washer and then secure with a brass nut or brass wingnut. Tighten until the rubber washer in the tank puckers; don't overtighten or you could crack the tank. You want everything going into the tank to be brass.

I have reservations about the head of the bolt clearing the hole in the base. As I've said, I'm no plumber, so I suggest you wait for a pro before doing anything.

Good luck and keep us posted.