The bowl on one toilet will not empty when we flush. We held the flapper open and it still didn't flush completely. It is obvious that the water level has dropped in the tank b/c you can see the old line from a week ago. This is now happening on a 2nd toilet in the house. The water level in that tank is lower, also. We have recently had the PRV on our water meter replaced. Didn't know if that could be part of the problem. There is no bubbling when we flush, but when we dump a bucket of water into the bowl when we flush, it DOES completely empty. We tried to add more water in the tank, but the water is already at the top of the overflow pipe. We can't figure out how to get more water in the tank with this short overflow pipe. We've lived here for 3 years and this has just started happening.

Is it COLD where you live......sounds like a Venting problem.....possibly HoarFrost............

"...measure once.....cut twice....throw that one away and cut a new one...."

It is cold where we live. We're in Colorado, and it has been in the single digits the past week. That sounds like it is our problem. Thanks so much! How do we go about getting rid of the hoarfrost?

Hoar frost can be prevented in most cases by increasing the vent terminal to 4" diameter as the vapors that freeze inside the opening cannot bridge a 4" gap

We flushed out the plumbing vents from the roof, and that seemed to help. There was definitely some hoar frost. We then removed the blue tablets we had put in the toilet tank weeks ago that were supposed to help keep the toilet clean. Now both toilets work perfectly again.
Thank you!

Here's a link to the BlueGooStory

http://www.toiletology.com/blue-goo.shtml

We don't get much hoarfrost in Florida

"...measure once.....cut twice....throw that one away and cut a new one...."