A matching brand or flush rating does not establish a tank-and-bowl match
Confirm a replacement toilet tank by finding an explicit manufacturer pairing for the exact tank and bowl identifiers. A shared collection name, similar mounting appearance or the same gallons-per-flush number is not that evidence. Keep the complete toilet's identifier alongside both component identifiers; they can be three different model numbers.
This is a document-checking method for two-piece tank-type toilets, not an installation procedure or a universal compatibility chart. The example below demonstrates how to read one dated specification sheet. It does not authorize substituting a part on an unidentified existing toilet.
Read an explicit pairing as a relationship
In KOHLER's K-4467 tank specification sheet, the retrieved document carries a December 4, 2018 footer. It identifies two combinations: K-4467 with K-4199 gives complete toilet K-3999, and K-4467 with K-5393 gives K-5481. The sheet states a 1.28 GPF tank rating. These are facts about that document's listed configurations, not evidence that every similarly named tank or bowl is interchangeable today.
| Tank in the cited sheet | Listed bowl | Complete toilet identifier |
|---|---|---|
| K-4467 | K-4199 | K-3999 |
| K-4467 | K-5393 | K-5481 |
The table contains one tank identifier, two bowl identifiers and two complete-toilet identifiers: five distinct model strings describing two explicit relationships. It does not describe five complete toilets or every possible combination among five parts. This small counting exercise shows why a list of names is weaker than a documented pairing.
Build an evidence record before deciding
| Record | What to preserve | Decision if unresolved |
|---|---|---|
| Installed components | Exact tank and bowl markings, including relevant suffixes | Ask the manufacturer to identify them |
| Proposed replacement | Full part/model designation and what the package includes | Do not infer included hardware from a photograph |
| Pairing statement | The document location naming both components | Mark the pairing unverified |
| Document applicability | Revision, market and any model conditions | Resolve conflicting or obsolete documents |
| Complete configuration | The assembled toilet identifier and relevant current listing | Keep certification status unconfirmed |
Our three-way screening rule is simple. An exact documented match is evidence to continue with the applicable installation instructions. A documented exclusion rules out that proposed match. Missing or conflicting documentation leaves the question unresolved. Absence from one old sheet is not proof of incompatibility, just as similar dimensions are not proof of compatibility.
If a seller supplies only a tank number, request the existing bowl identifier and the manufacturer's pairing record. If the available sheet names a different suffix, keep the suffix discrepancy visible. Do not remove it during a search merely to obtain a match. Where a manufacturer has revised a product, ask which instructions apply to the actual components being joined.
Keep fit, performance and certification as separate checks
An explicitly listed pairing still does not establish that the complete toilet fits your room, that an old component is serviceable, or that a historical configuration remains currently certified. Our rough-in and footprint checklist addresses the room-fit question. Our flush-test explanation addresses the limits of performance evidence.
For current label status, consult the official WaterSense search using the complete configuration. A saved directory flush rating is not a replacement-parts catalog. No fixture was assembled for this article, and no pairing beyond the two explicitly reported historical document relationships is asserted.