Toilets losing water

Three toilets in total. One brand new the others are ten years old which is the age of the home. Not too long ago I noticed once I installed the new toilet in the powder room that the toilet bowl was losing about one to one an a half inches of water over a day or so. Then I noticed the other toilets doing the same. Called two plumbers who checked everything including the roof stack to see if there was an issue there. No issues found. No evident leaks anywhere however I cannot figure out where the water is going.

Does anybody have any ideas on this issue

Many thanks
Dyno1

That sounds very odd. I have no idea.... Hopefully one of the experts here can weigh in.

Did they check the main drain for a partial blockage?

I will say no as both plumbers checked everything on the toilets, including any type of water leaks and then the roof stack. Being very unfamiliar with plumbing where should I look for the main drain? Would this be something I could check and attempt to remedy? And out of curiosity how would a blockage of the main drain "syphon" the water out of the toilets? I appreciate you taking time out to answer.

Dyno1

Just to confirm, the water is draining from the bowl and not the tank behind the toilet?

I only know of a few reasons for the bowl to drop the water.

1) A partial clog of the sewer line

2) A crack in the bowl

3) A disruption in the sewer line, like a string jammed in the trap below the toilet, which is allowing the water to be wicked out.

I would recommend purchasing a $3.00 wax ring, pulling one of the toilets, and conducting an inspection under the base of the toilet. While it is pulled, I'd snake the sewer line, because I honestly believe this is where your problem is.

So basically the trap it losing water. That is strange. Like havasu said, I'd pull the toilet and inspect the bottom. Maybe there is a crack in the bottom of the trap, but the water is still allowed to go down the drain, so you're not seeing leaks past the wax ring. I'd also say a possible vent issue. It's weird, but on windy days, Ive seen my own toilet trap level randomly drop and slightly move the existing water.... The extra air flow into the vent must be causing issues with the trap level.

Thank-you again for your time to respond.

Two of the toilets are almost ten years old and the new toilet is only months old and when this all started American Standard thought the same thing as you - a cracked bowl so they sent me and I replaced it with this new toilet. This was on the main floor of the house and the other two toilets are upstairs.

Since the plumbers did check some other things I feel strongly that it is the sewer line and would like to pursue that idea. What should I do and where do I look to do this job. What tools would you recommend and is this really a job a professional plumber should do.

By the way this is affecting all three toilets and that is why I don't think anything is jamming the trap as I assume each toilet as a trap. Unless if one trap would affect all the other toilets/

Again I appreciate your input

Many thanks
Dyno1

The clog might not be in the trap then. I had an issue with a clog in my main soil pipe recently. First we noticed the water level in the toilet bowl was low. Then gurgling and bubbling in the shower upstream followed by water around the toilet. Seems it blew the wax seal. I had to go to the cleanout with a 50' snake to clear it. If you remove the toilets again, you might want to try running a snake through to clear it. Wear gloves and have a rag to wipe off the snake as you pull it back out (You should probably get a sturdy plastic bag in which to put the snake when you are done pulling it out so it won't get sewage on other things once its out). Maybe try this with each toilet.

If that doesn't clear up the problem, then I don't know.