Replace a Kohler Shower Valve: What the Sources Say

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To replace Kohler shower valve parts, the job is usually to swap a cartridge or the mixer cap after the water is shut off and the trim is removed. The three sources below describe that work for different Kohler valve types. They do not describe one procedure that fits every Kohler shower. Valve replacement is plumbing work that touches the water supply inside a wall, so this guide explains what the sources say and recommends that a licensed plumber or contractor do the replacement. Shut off the water supply before you remove any trim or touch the valve.

Quick answer

• Identify the valve type first. The Kohler resources sheet is for a valve cartridge assembly, the Kohler technical sheet is for a recessed thermostatic shower valve, and the Danco sheet is for a cartridge made for Kohler valves.
• Shut off the water first. Each source starts there, and the Kohler sheets say to shut off the water supply or the main supply.
• The Danco sheet describes replacing a mixer cap with new O-rings and silicone grease, then reinstalling the trim and checking for leaks.
• Thermostatic valves need a temperature check after installation, and the Kohler technical sheet says cleaning the cartridge may be needed when water is very hard.
• Hire a licensed plumber for valve replacement. Keep a plumber involved for any pipe, fitting, or wall work.

How we chose these sources

The three sources were chosen because each is a manufacturer or parts-maker instruction sheet that names its publisher and covers a Kohler valve or a cartridge for one. The Kohler resources sheet, catalog number 113780, covers a valve cartridge kit with a setscrew, handle, and bonnet. The Kohler technical sheet is an installation instruction for recessed thermostatic bath and shower trim and valves, with model numbers 20936T and 20938T. The Danco sheet is an installation instruction for a cartridge for Kohler valves. Danco is a separate company from Kohler, so it counts as an independent publisher.

Retail listings were not used for the steps. Blocked pages and error responses were not counted. None of the three is a government or standards body, so the guidance is manufacturer instruction, not code.

Identify your valve before you buy a part

The three sources describe different kinds of valve, and a part for one will not necessarily fit another. The Danco sheet says it is a cartridge for Kohler valves and describes a mixer cap with a large O-ring and two small O-rings, plus a pressure-balance adapter that stays in place. The Kohler technical sheet describes a thermostatic valve with a temperature handle and a flow handle, a cartridge with a stop assembly, and a recessed mounting box. The Kohler resources sheet describes a valve cartridge with a setscrew, sphere, cap, and bonnet, which is the layout of a faucet valve.

Before you buy a replacement, find the model number on the valve or the trim, and compare it with the sheet you are using. Also note the type: a single-handle mixing valve, a pressure-balance valve, or a thermostatic valve. The Danco sheet says to check the original equipment manufacturer catalog for how to remove the valve trim, which is a good starting point for any Kohler valve.

Shut off the water and remove the trim

Every source starts with the water supply. The Danco sheet says to “turn OFF the water supply” and then remove the valve trim kit. The Kohler resources sheet says to shut off the water supply and then lift the faucet handle to relieve water pressure. The Kohler technical sheet says to shut off the water supplies to the faucet, and to shut off the main water supply, while observing local plumbing codes.

Once the water is off, remove the handle, sphere, or trim as the sheet directs. The Kohler resources sheet describes loosening a setscrew, removing the handle and cap, and unthreading the bonnet. The Danco sheet says to remove all the screws and keep them. Take photos of the parts as you go. The sources do not give a sequence for every valve, so the photos help you put things back in the same order.

Do not force a valve out of the wall. The Kohler resources sheet describes pulling the valve from the faucet body and then inserting the new valve so the posts line up with the holes in the body. If the valve does not come out easily, stop and call a plumber.

Replace the cartridge or mixer cap

For the Danco cartridge sheet, the work is focused on the mixer cap. The steps as the sheet lists them are: remove the screws, remove the mixer cap from the valve body, and discard the old cap with its O-rings. The sheet says the pressure-balance adapter “is just for reference” and does not need to be separated from the valve body. Apply silicone grease to the new small O-rings, place them on the back side of the new mixer cap, then place the new large O-ring on the back end of the cap. Screw the new cap into the valve body with the screwdriver.

The Danco sheet notes that the mixer cap has the word “UP” on its front face to help with orientation. Check that the word faces the direction the sheet shows before you tighten. The sheet lists “Silicone Grease (INCLUDED IN THIS KIT)” among the tools and materials, and says a screwdriver and pliers are needed but not included.

The Kohler resources sheet describes a different sequence. The cartridge is pulled, the new valve is inserted with its posts aligned, and then the bonnet, sphere, cap, handle, and setscrew are reinstalled. The sheet says the purpose is “to replace the valve cartridge assembly.” Because it describes a faucet cartridge, it does not describe a shower trim kit. Use it only if your valve matches its layout.

For the Kohler technical sheet, the valve is a thermostatic cartridge in a recessed box. It asks the installer to check that the hot and cold supplies are not reversed. The sheet covers the case where the hot and cold supplies are “connected inversely,” and says the installer must then swap the hot and cold insert assemblies. It also says to ensure that all coupling nuts are tight, and to turn on the main water and check for leaks.

Check the supply lines and the connections

The Kohler technical sheet says to flush the water supply pipes thoroughly to remove debris before installation, and to inspect the supply tubing for damage and leakage, replacing it as needed. It also says to check for leaks before covering the pipes, and to repair any leak found. Those points matter before you close the wall. A slow leak at a supply connection can stay hidden behind a finished wall for a long time.

The Kohler technical sheet also gives a pressure test limit, which is a point for the plumber to check, not for a home user. It says the test pressure should stay below a stated value and the test should not run longer than a stated time. Those numbers are for the installer, and this guide does not repeat them.

Temperature setting on thermostatic valves

If the valve is thermostatic, the Kohler technical sheet has a separate step. The installer must carry out a temperature verification and setting during commissioning of the valve. The sheet says that failing to do so “may lead to higher than expected temperatures during showering.” The steps are to run the water until the temperature stabilizes, measure the outlet temperature with a thermometer, and adjust the setting if the reading is out of range. The sheet gives a target range and a safety stop for the setting, which apply to the model it covers.

This is a step to leave to a licensed plumber. Measuring the outlet temperature and adjusting a thermostatic stop is work that affects scald risk, and the sheet describes it as part of commissioning the valve.

Hard water and cleaning the cartridge

The Kohler technical sheet says that “very hard water can obstruct the filters” on a thermostatic cartridge. It describes removing the cartridge and soaking it in warm vinegar. The sheet also says to make sure the black line on the cartridge lines up with the groove before reinstalling, and to align the stop pin with its notch. For cleaning a finish, the sheet says to use mild soap and warm water, dry the surface, and avoid abrasive cleaners or solvents.

If water flow drops over time, check for hard water deposits first. For a related problem, see how to tell if your water is hard. For an older valve or cartridge, the replacement may be the better fix. Ask the plumber to check the cartridge before you buy a new one.

When to hire a licensed plumber

Hire a licensed plumber or contractor for a valve replacement. The sources describe work that touches the water supply and the wall, including cutting or removing trim, pulling a valve from its body, checking the connections, and setting the temperature on a thermostatic valve. Any work that changes the supply pipe, the fittings, or the wall structure is outside what a homeowner should attempt. If the valve is inside a wall with no access panel, the plumber will need to open the wall.

Ask the plumber to confirm the valve type and model, to replace any worn supply tubing, to check for leaks before closing the wall, and to set and record the temperature on a thermostatic valve. Those are the steps the Kohler technical sheet and the Danco sheet describe, and they are the steps most worth confirming on a quote.

If you also have a handheld shower on the same supply, see how to install a handheld shower head for the head itself, which is a separate job from the valve.

What we could not verify: what the sources do not say

• The sources do not say which Kohler shower valve models each step fits. The technical sheet covers model numbers 20936T and 20938T. The resources sheet and the Danco sheet do not name a shower valve model.
• No source gives a torque value for the screws, setscrew, or bonnet. Tighten by the sheet’s instruction and the plumber’s judgment.
• No source describes replacing the valve body inside a wall, opening a finished wall, or moving a supply line.
• No source gives a code requirement for valve replacement or for permits. Local rules vary.
• The Kohler resources sheet is dated 1997 in its copyright line and describes a faucet cartridge. It may not match a current shower valve.
• No source says whether a sealant or grease other than silicone should be used on the O-rings. The Danco sheet calls for silicone grease.
• No source opened says how long a replacement cartridge will last.

FAQ

Can I replace a Kohler shower valve myself?

The sources describe the steps, but they are written for a trained installer, and they include a thermostatic temperature setting and wall connections. Hire a licensed plumber or contractor for valve replacement.

How do I know which Kohler valve I have?

Find the model number on the valve or trim and compare it with the sheet. The technical sheet covers recessed thermostatic valves with models 20936T and 20938T. The Danco sheet covers a cartridge for Kohler valves. Check the type: thermostatic, pressure-balance, or single-handle mixing.

Do I need to shut off the water before starting?

Yes. All three sources start with the water supply. The Danco sheet says “Turn OFF the water supply,” and the Kohler technical sheet says to shut off the main supply, observing local codes.

What do I check after installing a new valve?

Turn the water back on and check for leaks. The Danco sheet says to “CHECK FOR LEAKS,” and the Kohler technical sheet says the same before the wall is closed. On a thermostatic valve, the sheet also calls for a temperature check.

What if my shower water is weaker after the replacement?

The Kohler technical sheet says very hard water can block the filters on a thermostatic cartridge and reduce the flow. It describes cleaning the cartridge by soaking it in warm vinegar. If the flow stays low, have the plumber check the cartridge and the supply.

Do I need a new O-ring kit?

The Danco sheet says to discard the old O-rings and install new ones with silicone grease when replacing the mixer cap. Buy the part that matches your valve’s model before you start.

Bottom line

A Kohler shower valve replacement depends on the valve type. Shut off the water first, identify the model and type, and follow the sheet that matches your valve. Check for leaks before closing the wall, and check the temperature on a thermostatic valve. Because valve replacement touches the water supply and the wall, a licensed plumber or contractor should do the work.

Sources

• Kohler Co., “Valve Kit” installation sheet, catalog 113780. https://resources.kohler.com/webassets/kpna/catalog/pdf/en/113780_9.pdf (opened 2026-10-27)
• Kohler Co., “Installation Instructions,” recessed thermostatic bath and shower trim and valve, models 20936T and 20938T. https://techcomm.kohler.com/techcomm/pdf/20938T-3_Installation%20Instructions_1318848-2A_C1.pdf (opened 2026-10-27)
• Danco, Inc., “Installation Instructions for Cartridge for Kohler,” model 11020i. https://danco.com/wp-content/uploads/2022/04/9D-11020i_04192022.pdf (opened 2026-10-27)