Does it come with a seat?

No. The seat and the supply line are sold separately. Any elongated toilet seat will fit.

Will it fit my existing floor flange?

It uses a standard 12-inch rough-in, which covers most US bathrooms. Measure from the finished back wall to the flange bolts before buying.

How does it compare with a 1.28 gpf toilet?

It uses more water per flush but delivers a stronger, more forgiving flush. Newer 1.28 gpf models save water but can need a second flush more often.

Is it a dual-flush toilet?

No. It is a single-flush gravity toilet with a left-hand trip lever.

The tank and the bowl. The wax ring, supply line, seat and bolts are not included.

Is it hard to install?

It is a standard floor-mount two-piece install. The three-bolt quick-connect helps, but the box is heavy, so plan for two people.

Where can I buy the KOHLER K-3978 Wellworth Two-piece elongated toilet, 1.6 gpf?

7 stores we checked sell it, including Ferguson Home, Wayfair, KOHLER Stores by General Plumbing Supply, GNkitchenandbath, Amazon.

KOHLER K-3978 Wellworth Two-piece elongated toilet, 1.6 gpf

Q: Where is the KOHLER K-3978 Wellworth Two-piece elongated toilet, 1.6 gpf cheapest?

At KOHLER Stores by General Plumbing Supply, for $326.40, as of our latest check.

Best price now

$326.40at KOHLER Stores by General Plumbing SupplyChecked 6 h ago

Compared across 7 stores. Prices are checked against each store and labelled with when.

Visit KOHLER Stores by General Plumbing Supply

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What reviewers say

Owners generally describe the Wellworth as a reliable, no-frills toilet that flushes well and is easy to keep clean. Complaints tend to focus on the separately sold seat and on the canister valve needing occasional attention.

What people mention

Flush powerPraisedOwners say the Class Five flush clears the bowl reliably in one go.
SeatCriticisedBuyers note the seat is not included and must be bought separately.
Water useMixedSome owners point out the 1.6 gpf flush uses more water than newer 1.28 gpf toilets.
BuildPraisedReviewers describe the vitreous china as solid and the finish as easy to wipe down.
Valve upkeepCriticisedA few owners report the canister flush valve wearing out and needing replacement.
InstallationMixedThe three-bolt quick-connect setup is straightforward, but the two-piece body is heavy to set alone.

About the KOHLER K-3978 Wellworth Two-piece elongated toilet, 1.6 gpf

A benchmark of American innovation and engineering, this Wellworth toilet displays graceful curves that fit a wide variety of bathroom motifs. A powerful 1.6-gallon flush delivers strong, reliable performance, and the elongated bowl ensures comfort.

• Two-piece design

• Elongated bowl offers added room and comfort

• 1.6 gpf (6.0 lpf)

• Left-hand Polished Chrome trip lever

• Combination consists of the K-4468 tank and the K-4198 bowl

• Coordinates with other products in the Wellworth collection

• KOHLERs canister flush valve harnesses the natural force of gravity and optimizes flushing performance

• Class Five canister optimizes the flow out of the tank, harnessing gravity and the natural, powerful reducing cascade of water to increase the power and effectiveness of the flush

• Overall dimensions: 30" L x 18" W x 28-7/16" H

• Product weight: 0.2 lb

• Material: Vitreous China

• Installation: Floor-mount

• Suitable for residential use

• KOHLER® Toilets and Seats Limited Warranty