Easy Way To Install a Kohler Highline Toilet

  • 01 of 11

    Making the Kohler Highline Toilet a Little Easier To Install

    Kohler Highline Toilet
    Kohler Highline Toilet. © Lee Wallender

    The Kohler Highline toilet is a standard, low-cost, all-inclusive toilet waiting right there on the shelves of Home Depot to be taken home.  This is not necessarily a good thing, though.

    Perhaps by virtue of its low price and mass market reach, the Kohler Highline comes with its own particular collection of miseries awaiting the DIY installer.  Here's one:

    The installation instructions are printed on the top of the box, right there on the flaps.  Not a stroke of genius on Kohler's part,...MORE because to access the product, the buyer must remove the tape holding the flaps together, thus ripping off half of the instructions.

    That's just the start.  With this guide, I hope to guide you through the installation and some of those obstacles.

    If you haven't done so already, turn off the water supply to your existing toilet or water main to your entire house.  Then, put on a pair of gloves and remove your existing toilet before continuing to the next step.


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  • 02 of 11

    Install Wax Ring On Toilet Base

    Install Wax Ring On Toilet Base
    Install Wax Ring On Toilet Base. © Lee Wallender

    Most toilets install with a wax ring.  In the spirit of "If it ain't broken, don't fix it," this strangely archaic method continues through the decades as a fairly effective way of connecting the toilet to the sewer pipe, ​via the toilet closet flange.

    Waxless silicone seals like Sani-Seal are a good replacement, but wax is still the default method.

    Extra-Thick Wax Rings

    But one improvement you can make is to ignore the Kohler-provided wax ring and buy an extra-thick wax ring such...MORE as the Fluidmaster or Lasco for under $6.  This will ensure a tight seal, as long as you have the right distance between toilet and floor.  If the gap is too far, use a flange extender ring.  This is a super-easy install that will save your bathroom from potential sewage leaks out of the base of the toilet.

    Apply To Base

    Turn the toilet upside down on carpeting or another soft surface to prevent chipping or scratching the porcelain.

    With the wax ring softened to room temperature, peel off the wrapping and stick it to the base of the toilet., with the rubber gasket portion pointing up (which will be down after the toilet is installed).

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  • 03 of 11

    Rest Toilet Down On Closet Flange

    Set Toilet On Closet Flange
    Set Toilet On Closet Flange. © Lee Wallender

    Flip the toilet upside-down (so that it is now upright, with the bowl facing upward) and carefully set it onto the floor.  If applied while soft, the wax ring should remain sticking to the toilet even upside-down.

    It helps to have an assistant for this.  Let the 2 closet flange T-bolts insert through the holes at the base of the toilet.

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  • 04 of 11

    Press Down Toilet and Wax Ring With Weight

    Press Down Toilet and Wax Ring With Weight
    Press Down Toilet and Wax Ring With Weight. © Lee Wallender

    When the bolts are through the holes on the base of the toilet, press down on the toilet to compress the wax ring.

    This is one way that wax rings are superior to silicone rings, because wax will continue to compress as far as you want it to.  Silicone rings will stop compressing at a certain point.

    Be patient and use your entire weight to press the toilet down, until the base is fully touching the bathroom floor.

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  • 05 of 11

    Measure Toilet From Back Wall

    Measure Toilet From Back Wall
    Measure Toilet From Back Wall. © Lee Wallender

    While you can always eyeball the toilet in relation to the back wall to get it perpendicular, using the tape to rough measure it is a nice touch and provides a bit of comfort.

    Good reference points for this are the 2 holes on the toilet rim that will accept the toilet seat bolts.  In this image, the holes are each on-center roughly measured at 6" away from the back wall.

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  • 06 of 11

    Tighten Bolts At Base Of Toilet

    Tighten Toilet Bolts At Base
    Tighten Toilet Bolts At Base. © Lee Wallender

    Add the included plastic washer, metal washer, and bolt (in that order) onto the 2 protruding brass T-bolts sticking up from the floor.

    Kohler's instructions merely state that you should not overtighten.  I will add the warning that overtightening may crack the Highline's base, greatly hampering usage of the toilet because it will no longer be securely attached to the floor.  

    So, use a torqued wrench or simply use a Channel-Lock wrench, which makes it virtually impossible to over-tighten.

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  • 07 of 11

    Valuable Tip:  Press Gasketed Bolts Into Toilet Tank

    Press Gasketed Bolts Into Toilet Tank
    Press Gasketed Bolts Into Toilet Tank. © Lee Wallender

    Here's the part that symies some owners of the Kohler Highline:  resting the tank on the base.  The problem:

    If you take the tank in "as delivered" state and rest it on the base, it will be too high.  The bolts will not be long enough to extend through the base's holes.

    I scratched my head over this one for awhile.  And the Highline instructions are silent on this.

    As it turns out, you need to force the gasketed bolts back into the tank.  For some reason, the tank is delivered with...MORE these gasketed bolts protruding.

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  • 08 of 11

    Tighten Tank Bolts With Socket

    Tighten Tank Bolts With Socket
    Tighten Tank Bolts With Socket. © Lee Wallender

    Rest the tank on the base area, inserting the 4 bolts into the holes on the base.

    Turn the nuts onto the bolts with your fingers.

    Again, Kohler's instructions were silent on this, but I used a 13mm socket from a socket-wrench set to assist in turning the nuts into the gaskets.

    As before, Kohler doesn't want you to overtighten.  As long you tighten by hand, you should be fine.

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  • 09 of 11

    Level Toilet Tank On Bowl

    Level Toilet Tank On Toilet Base
    Level Toilet Tank On Toilet Base. © Lee Wallender

    As you are turning the tank's bolts, keep a bubble level on the tank, with the tank lid removed.

    This helps you adjust side-to-side level.  Be sure also to move the level 90 degrees to check for front-to-back level.

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  • 10 of 11

    Cut Off Bolts At Toilet Base

    Cut Off Bolts At Toilet Base
    Cut Off Bolts At Toilet Base. © Lee Wallender

    Another thing that Kohler could have done better with the Highline toilet:  provided 2 sets of bolts for the base.

    Instead, you have one set of bolts and this set must be hacked off at about mid-point.  A multi-tool equipped with a metal blade makes short work of these brass bolts.

    To add to the fun, the vibration of the tool will slowly loosen the bolts.  You can prevent this by securing the end of the bolt with a needle-nose Vise-Grip.  

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  • 11 of 11

    Attach and Turn On Toilet's Water Supply

    Attach and Turn On Toilet's Water Supply
    Attach and Turn On Toilet's Water Supply. © Lee Wallender

    Hand-tighten the water supply to the bottom of the Highline's tank.  It is impossible to over-tighten as the plastic nut is difficult to grip.

    Set a low plastic basin below the water supply line.

    Turn on the supply knob slowly.  The Kohler Highline's tank will fill, and the toilet will be ready for use as soon as the tank is filled.

    If you see no leaks in the plastic basin after 10 minutes, it will be safe to remove.

    Install Toilet Seat

    As Kohler did not supply me with the necessary materials...MORE to install the seat, I will update this when those materials have arrived.