Kohler Rite-Temp Shower Cartridge by Valve: GP800820, GP77759, GP876851 and GP800881, Which One Your Valve Takes
Kohler's parts pages: GP800820 is the cartridge for K-304 and K-11748, GP77759 is only the mixer cap, GP800881 fits K-8304. Ask about Kohler's warranty first.
- Verified
- Updated
- 8 min read
- 11 sources
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Short answer
Kohler prints the match on its own service-part pages. The Kohler GP800820 is the Rite-Temp pressure-balancing unit cartridge, compatible with Kohler shower valves K-304 and K-11748, and Kohler’s Common Service Parts brochure says it replaces the older GP500520. The GP77759 that most listings call a cartridge is, in Kohler’s words, the mixer cap kit for the pressure-balancing unit: it sits in front of the cartridge and ships with a metal collar, and it fits the same two valves. Kohler’s brochure lists GP876851 as the kit made of GP800820 plus GP77759, which is the box to buy when the valve drips and the cap is worn. The GP800881 is a different part, Kohler’s one-piece cartridge for the K-8304 Universal Rite-Temp valve, rated 5 gpm at 45 psi. Kohler’s Faucet Lifetime Limited Warranty mails a free cartridge for a dripping faucet to the original buyer with the receipt; it never names shower valves, so call 1-800-456-4537 and ask first.
The picks
K-304 or K-11748 valve that drips, runs hot first or will not hold temperature
Kohler GP800820 pressure-balancing unit cartridge, genuine
Kohler's brochure: Rite-Temp cartridge for most 1/2 inch pressure-balancing valves, replaces GP500520, resists aggressive water; Kohler's part page: compatible with K-304 and K-11748
Cap is cracked, springs fell out, or the handle grinds; the cartridge itself is fine
Kohler GP77759 mixer cap kit, genuine
Kohler's brochure: mixer cap kit for the pressure-balancing unit, stem cap for most 1/2 inch pressure-balancing valves; Kohler's K-304 page: ships with a metal collar. Not the cartridge
K-8304 Universal Rite-Temp valve body
Kohler GP800881 one-piece cartridge, genuine
Kohler's part page: replacement cartridge for the K-8304 pressure balance valve, single sequential cartridge, 5 gpm maximum flow at 45 psi; Kohler's brochure: one-piece pressure-balancing cartridge
Wants cap and cartridge in one box and accepts a seller's fit claim rather than Kohler's
nipponAsia GP876851 cap and cartridge kit, third-party
Seller's listing only: mixer cap plus pressure-balancing unit sold as a GP876851 equivalent for Kohler valves. No Kohler fit statement and no certifier listing found for it
If a seller’s title says “Kohler GP77759 cartridge”, the box holds the cap, not the cartridge: Kohler never calls GP77759 a cartridge, and a dripping valve is fixed by the part behind it.
Which Kohler cartridge fits which valve?
Everything below is copied from Kohler’s brochure, service-part pages and K-304 instructions; where two Kohler documents print different numbers for one kit, both appear.
| Valve family and body | Part | What Kohler calls it | What Kohler says it includes or fits | Kohler source |
|---|---|---|---|---|
| Rite-Temp 1/2 inch K-304, and K-11748 (the K-305 replacement) | GP800820 | Rite-Temp pressure-balancing unit (PBU) cartridge | Cartridge for most 1/2 inch pressure-balancing valves; replaces GP500520; compatible with K-304 and K-11748; Memoirs, Fairfax, Forte, Revival, Kelston, Bancroft and Stillness trim | Brochure JOB019705-02; GP800820 part page |
| Rite-Temp 1/2 inch K-304 and K-11748 | GP77759 | Mixer cap kit for pressure-balancing unit | Stem cap for most 1/2 inch pressure-balancing valves; the replacement cap includes a metal collar; compatible with K-304 and K-11748; Memoirs, Fairfax, Revival, Bancroft, Stillness, Forte, Purist and Coralais trim | Brochure; K-304 instructions; GP77759 part page |
| Rite-Temp 1/2 inch K-304 and K-11748 | GP876851 (K-304 page prints GP76851) | Cartridge and mixer cap kit | “Consists of GP800820 and GP77759” | Brochure; K-304 instructions |
| Universal Rite-Temp K-8304 | GP800881 | One-piece pressure-balancing cartridge | Replacement cartridge for the K-8304 pressure balance valve; single sequential cartridge; 5 gpm maximum flow at 45 psi | Brochure; GP800881 part page; spec sheet K-8304-KS |
| Older Coralais shower trim, square brass stem | GP77886 | Mixer cap kit | Cap only; no cartridge number printed for this trim | Brochure |
| Older Coralais shower trim, square plastic stem (also Sterling shower units) | GP71969 | Mixer cap kit | Cap only; no cartridge number printed for this trim | Brochure |
Kohler’s brochure prints no cartridge number for the Mastershower or Triton families, and its K-8304 and K-11748 spec sheets print no service parts, so those rows do not exist here. The Moen and Delta equivalents of this table are Moen cartridge by faucet and Delta cartridge by model.
How do you tell which valve you have?
Kohler’s service pages identify the valve by the parts in front of you rather than by a stamped number; the cross-brand method is in which faucet cartridge do I have.
| What you can see once the trim is off | What Kohler prints | Part |
|---|---|---|
| A black cap held by two screws and a collar, with a white pressure-balancing unit behind it | Kohler’s K-304 page: match the cap to its picture, then replace it with GP77759; the PBU behind it pulls out with pliers | GP800820 cartridge, GP77759 cap, or the GP876851 kit for both |
| A red collar under the handle (black on older models) | Kohler’s temperature article: the limit stop collar on a K-304 Rite-Temp valve | Same K-304 parts |
| A cap with a removable section whose springs have fallen out | Kohler’s dripping article: the older mixer cap design, changed in 2005; boots and springs are not sold as service parts | GP77759 cap |
| A valve with a push-button or integral diverter, installed after June 2010 | Kohler’s dripping article: the K-305 was discontinued in June 2010 and replaced by the K-11748 | GP800820 and GP77759 |
| One cartridge that comes out in one piece with no separate cap | Kohler’s brochure and part page: the K-8304 Universal Rite-Temp valve | GP800881 |
The collar goes in front of the mixer cap: Kohler’s dripping article names a collar placed between the PBU and the cap as a cause of a leak after a new service kit.
Will Kohler mail the cartridge free?
Possibly, and asking costs one phone call. Kohler’s Faucet Lifetime Limited Warranty, document 1353511-12, warrants faucets made after January 1, 1997, “to be leak and drip free during normal residential usage for as long as the original consumer purchaser owns their home”, and if one drips, “Kohler Co. will, free of charge, mail the cartridge necessary to put the faucet in working condition”. The document says faucet and never names a shower valve, so whether a Rite-Temp valve qualifies is Kohler’s answer to give, not this page’s.
The conditions from the same document: the original sales receipt with every claim, no removal, installation or labor charges covered, five years for commercial use, ten years for a rented residential unit, and Kohler may reject claims on products bought from unauthorized sellers. The number is 1-800-4-KOHLER (1-800-456-4537).
Call Kohler before you buy
If you are the original buyer with the receipt, ask Kohler first: its faucet warranty may cover the cartridge. Buy the genuine GP800820 when you need it today or bought the house with the valve in it, and add the genuine GP77759 cap only if the cap is cracked or its springs are loose.
Genuine or aftermarket?
Kohler’s warranty excludes damage caused by “alteration to the product” and applies only to products bought from an authorized seller; it does not name aftermarket cartridges. OwnerSpec has fitted neither kind, and the third-party GP876851 kits carry only their sellers’ fit claims, with no certifier listing found.
On 11 October 2026 the Amazon catalog reported the genuine GP800820 , GP77759 and GP800881 in stock. No Kohler-branded GP876851 kit surfaced, so the only cap-plus-cartridge box linked is the third-party nipponAsia kit . Skip it if you want Kohler’s own fit statement behind the part.
What else makes a Rite-Temp valve misbehave?
A new cartridge does not fix a supply problem; Kohler’s dripping article lists the ones that mimic a worn part.
| Symptom | Kohler’s stated cause | Kohler’s fix |
|---|---|---|
| No water at all | The PBU needs pressure on both sides; Rite-Temp valves “require a minimum of 45 PSI on both the hot and cold supplies” | Confirm the stops are open; check supply pressure |
| Temperature swings or a noisy valve | More than 5 psi difference between hot and cold supplies | Have the incoming pressures measured and balanced |
| Hot comes on first | Hot and cold inlets reversed | Rotate the mixer cap per Kohler’s instructions |
| Showerhead drips up to 90 seconds after shutoff | Residual water draining | Wait, or clean the head in 50/50 white vinegar and water |
| Water from spout and showerhead at once | Pipe other than 1/2 inch copper between valve and spout, or debris in the ports | 1/2 inch copper; clear the debris |
Kohler’s spec sheet K-11748-K prints a 20 psi minimum operating pressure, a 125 psi maximum static pressure and a 1.5 gpm minimum rated flow at 45 psi; the K-8304-KS sheet holds outlet temperature within plus or minus 3 degrees F. Weak flow after a cartridge swap is a shower head question: best shower head for low water pressure or, at normal pressure, best shower head.
Kohler’s temperature article says the Rite-Temp limit stop should never be set above 120 degrees F, the same number argued in water heater temperature, 120 or 140. A valve that has dripped inside the wall also belongs with the smart leak detector review.
Frequently asked questions
Is the Kohler GP77759 a cartridge?
No. Kohler's Common Service Parts brochure lists GP77759 as the mixer cap kit for the pressure-balancing unit, and its K-304 instructions call it the mixer cap. The cartridge behind it is the pressure-balancing unit, GP800820 (Kohler: replaces GP500520). Sellers title GP77759 as a cartridge, which is why the cap alone arrives when the valve needed both parts.
Which cartridge does a Kohler K-11748 valve take?
Kohler's service-part pages list both the GP800820 pressure-balancing unit cartridge and the GP77759 mixer cap as compatible with Kohler shower valves K-304 and K-11748. Kohler's Rite-Temp dripping article says the K-11748 replaced the K-305, which was discontinued in June 2010, so a K-305 behind the wall points to the same two parts.
What is the difference between GP800820 and GP800881?
Kohler's brochure lists GP800820 as the Rite-Temp cartridge for most 1/2 inch pressure-balancing valves, used with a separate mixer cap, and GP800881 as a one-piece pressure-balancing cartridge for the K-8304 Rite-Temp valve. Kohler's GP800881 page prints 5 gpm maximum flow at 45 psi and names it the replacement for the K-8304 pressure balance valve only.
Will Kohler send a Rite-Temp cartridge for free?
Possibly. Kohler's Faucet Lifetime Limited Warranty says that if the faucet should leak or drip during normal usage, Kohler will, free of charge, mail the cartridge needed to put it in working condition, for the original consumer purchaser. The document says faucet and never names shower valves, so ask Kohler. The receipt is required and labor is excluded.
Why does a new Kohler Rite-Temp cartridge still leak or give no water?
Kohler's Rite-Temp dripping article lists two causes after a new service kit: O-rings not in perfect condition, or the metal collar placed between the pressure-balancing unit and the cap instead of in front of the mixer cap. For no water at all, Kohler says Rite-Temp valves need a minimum of 45 psi on both the hot and cold supplies.
Fact sheet and how to cite this page
- Answer
- Kohler’s parts pages match the GP800820 pressure-balancing unit cartridge to the K-304 and K-11748 Rite-Temp valves, the GP77759 to the same two valves as the mixer cap only, and the GP800881 one-piece cartridge to the K-8304 Universal Rite-Temp valve. Kohler’s Common Service Parts brochure lists GP876851 as the kit made of GP800820 plus GP77759. Kohler’s faucet warranty mails a free cartridge for a dripping faucet but never names shower valves.
- Applies to
- Kohler K-304 Rite-Temp 1/2 inch pressure-balancing valve
- Kohler K-11748 Rite-Temp 1/2 inch pressure-balancing valve with diverter (replaced the K-305 in June 2010)
- Kohler K-8304 Universal Rite-Temp 1/2 inch pressure-balancing valve
- Part: GP800820 pressure-balancing unit cartridge (Kohler: replaces GP500520)
- Part: GP77759 mixer cap kit
- Part: GP876851 cartridge and mixer cap kit
- Part: GP800881 one-piece pressure-balancing cartridge
- Compatibility basis
- Kohler’s Common Service Parts brochure JOB019705-02, Kohler’s service-part pages for GP77759, GP800820 and GP800881, Kohler Assist’s K-304 service part instructions and Rite-Temp dripping article, Kohler spec sheets K-8304-KS, K-11748-KS and K-11748-K, and Kohler’s Faucet Lifetime Limited Warranty 1353511-12
- Assumptions
- Kohler’s K-304 service instructions print the kit number as GP76851 while the Common Service Parts brochure prints GP876851 for the same cap-plus-cartridge kit; the table prints both as Kohler prints them.
- No Kohler document read at the last check lists a cartridge number for the Mastershower or Triton valve families, so they are not in the table. The brochure lists only two Coralais mixer cap kits, GP77886 and GP71969.
- Kohler’s spec sheets for K-8304 and K-11748 print no service-part numbers; the valve-to-cartridge match comes from the compatibility lines on Kohler’s service-part pages and the brochure.
- No certifier listing was found for any aftermarket Rite-Temp kit, so the one aftermarket kit on this page is labelled third-party and carries only its seller’s fit claim.
- Method
- Part numbers, valve compatibility, kit contents, flow and pressure figures and the service steps copied from Kohler’s brochure, service-part pages, Assist articles and spec sheets; warranty terms quoted from Kohler’s printed warranty. Amazon stock checked through the Creators API on 11 October 2026. OwnerSpec fitted no cartridge and tested nothing.
- Primary source
- Kohler, Common Service Parts brochure JOB019705-02 (GP876851, GP800820, GP77759, GP800881, Coralais mixer caps) (manufacturer or vendor document)
- Facts verified
- Last updated
- Cite as
- OwnerSpec, "Kohler Rite-Temp Shower Cartridge by Valve: GP800820, GP77759, GP876851 and GP800881, Which One Your Valve Takes", https://ownerspec.com/plumbing/parts/kohler-rite-temp-shower-cartridge-by-valve/, facts verified 11 October 2026.
Every figure above also appears, with its source, in the article. All sources ยท How OwnerSpec verifies numbers
Sources
- Kohler, Common Service Parts brochure JOB019705-02 (GP876851 consists of GP800820 and GP77759; GP800820 for most 1/2 inch pressure-balancing valves, replaces GP500520; GP77759 mixer cap kit; GP800881 for K-8304; GP77886 and GP71969 Coralais mixer caps) (manufacturer or vendor document)
- Kohler, Rite-Temp Pressure-Balancing Unit Cartridge GP800820 service-part page (compatible with K-304 and K-11748; Memoirs, Fairfax, Forte, Rite-Temp, Revival, Kelston, Bancroft and Stillness trim) (manufacturer or vendor document)
- Kohler, Rite-Temp Pressure-Balancing Mixer Cap GP77759 service-part page (compatible with K-304 and K-11748; Memoirs, Fairfax, Rite-Temp, Revival, Bancroft, Stillness, Forte, Purist and Coralais collections) (manufacturer or vendor document)
- Kohler, Rite-Temp Pressure Balance Cartridge GP800881 service-part page (replacement cartridge for K-8304; 5 gpm at 45 psi; Universal Rite-Temp) (manufacturer or vendor document)
- Kohler Assist, Rite-Temp K-304 Service Part Installation Instructions (GP77759, GP500520, GP76851 kit; metal collar included with the cap; older and current collar designs; 12 o'clock cap position) (manufacturer or vendor document)
- Kohler Assist, Rite-Temp Valve Dripping from Showerhead or Spout (K-305 discontinued June 2010, replaced by K-11748; 45 psi minimum on both supplies; 5 psi imbalance; collar placement; 2005 mixer cap change) (manufacturer or vendor document)
- Kohler Assist, Adjust the Temperature on a Rite-Temp Shower Valve (K-304; never above 120 degrees F; red or black collar) (manufacturer or vendor document)
- Kohler spec sheet K-8304-KS (valve body and cartridge kit; 5 gpm at 45 psi; outlet held within plus or minus 3 degrees F; ASSE 1016; one-piece reversible cartridge) (manufacturer or vendor document)
- Kohler spec sheet K-11748-KS (1/2 inch pressure-balancing valve with diverter; one-piece diaphragm cartridge; ASSE 1016) (manufacturer or vendor document)
- Kohler spec sheet K-11748-K (20 psi minimum operating pressure; 125 psi maximum static; 1.5 gpm minimum rated flow at 45 psi) (manufacturer or vendor document)
- Kohler, Faucet Lifetime Limited Warranty 1353511-12 (mails the cartridge free of charge; original consumer purchaser; receipt required; five years commercial; ten years rented; 1-800-456-4537) (manufacturer or vendor document)