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Toilet Repair – Fixing An Improper Air Gap On A Ballcock

By In TISH Repairs, Toilets On April 8, 2009

To avoid a cross connection between the water in your toilet tank and the water you drink, make sure the guts of your toilet are properly installed.  This is required by the Minnesota State Plumbing Code, section 4715.2150, subpart 2, under Flush Tanks.   An improperly installed ballcock requires repair for the Truth in Housing programs in Minneapolis, Bloomington, and Hopkins, and it’s considered a hazard in Saint Paul and Maplewood.

This is a very common defect, and the repair usually only takes a few seconds.  The diagrams below show what the two most common ball cocks should look like when properly installed, and the video below shows how to adjust a ballcock made by Fluidmaster, which is the most common one used today.  Click the diagrams for larger images.

Toilet FluidmasterBallcock

Standard Ballcock Air Gap

For a quick video clip which shows how to adjust the height of a Fluidmaster ballcock, click below.

For more information on common Truth In Sale of Housing defects, click on any of the links below.

Reuben Saltzman, Structure Tech Home Inspections – Email Minneapolis Toilet Inspections

About the Author


Reuben is a second generation home inspector with a passion for his work. He grew up remodeling homes and learning about carpentry since he was old enough to hold a hammer. Reuben has worked for Structure Tech since it was purchased by Neil in 1997, and is now co-owner and President of the company.


  • Toronto Toilet Repair 7 YEARS AGO

    Well, as a professional plumber from Toronto, I would say this article is very useful. I would recommend it to read to any homeowner.