Zurn Floor Drain: Complete Guide for Homeowners

Water always finds the lowest point in a room, and when that point lacks proper drainage, you get standing water, mildew, and warped subfloor. A Zurn floor drain solves that problem with a heavy-duty body, a removable strainer, and a trap that keeps sewer gas out of your living space. Zurn has built commercial-grade plumbing components for decades, and many of its drains are now common in residential basements, mechanical rooms, and curbless showers. This guide walks you through the models, sizing, and installation steps that actually matter.

Why Choose a Zurn Drain Over a Big-Box Brand

Most hardware-store drains are stamped from thin metal or molded ABS, and they flex underfoot. Zurn bodies are typically cast iron or PVC with thicker walls, which means they hold up under a poured slab and resist deformation when a forklift or appliance dolly rolls across them. That durability is the reason you see Zurn specified in warehouses, hospitals, and food-prep kitchens.

For a homeowner, the practical benefit is fewer callbacks. A quality drain installed once should outlast the floor around it. Replacement strainers and grates are widely stocked, so you are not hunting for an obsolete part five years later.

Common Zurn Floor Drain Models

Zurn organizes its drains by a “Z” series number, and each series targets a specific job. Knowing the family helps you order the right part instead of guessing at a counter.

• Z415 series: The workhorse for residential and light commercial floors. Cast-iron body, adjustable strainer head, available with 2-inch, 3-inch, or 4-inch outlets.
• Z550 / Z560 series: Designed for areas needing larger capacity, such as mechanical rooms with boilers or water heaters.
• FD2370 PVC series: A lighter, corrosion-proof option for slab-on-grade and basement pours where cast iron is overkill.
• Shower drains: Low-profile bodies with clamping collars and weep holes for tiled, mortar-bed showers.

Grate finishes range from polished nickel-bronze to plain cast iron. For a finished basement, a nickel-bronze square strainer looks far cleaner than raw metal and costs only a few dollars more.

Sizing the Outlet Correctly

Outlet size determines how fast the drain clears water, and the wrong size creates either pooling or wasted money. A standard residential floor drain uses a 2-inch outlet, which moves roughly 20 to 30 gallons per minute under gravity flow. That handles a washing machine discharge, a water heater pan, and the occasional hose-down.

Step up to a 3-inch or 4-inch outlet when you expect high-volume flow, such as a basement that floods during heavy storms or a garage you rinse with a pressure washer. Match the outlet to your existing drain line; reducing from a 4-inch line to a 2-inch drain throttles the whole system and defeats the purpose.

The Trap Primer Problem

Here is the issue nobody mentions until the smell shows up: a floor drain only blocks sewer gas while there is water sitting in its P-trap. In a rarely used basement, that trap water evaporates in three to eight weeks, depending on humidity, and then odor drifts up.

You have two fixes. Pour a cup of water down the drain once a month to refill the trap, or install a trap primer that automatically feeds a small amount of water each time a nearby fixture runs. Some Zurn assemblies accept a trap-seal device that uses a flexible membrane instead of water, which is ideal for drains that almost never see flow.

Step-by-Step Installation Overview

Setting a drain in a new pour is straightforward if you stage the parts before the concrete truck arrives. Retrofitting into an existing slab means cutting and patching, which adds a day.

1. Set the drain body so the strainer top sits 1/8 inch below the finished floor height. This lets water sheet toward the grate instead of pooling around it.
2. Connect the outlet to your P-trap and waste line with the correct couplings, then test for leaks before any concrete goes in.
3. Slope the surrounding floor at least 1/4 inch per foot toward the drain across a 2- to 3-foot radius.
4. Protect the strainer opening with tape or a plug so debris does not fall in during the pour.
5. After curing, remove the protection, install the strainer, and run water to confirm flow and a sealed trap.

If you are tiling over the drain in a shower, use the clamping collar to lock the waterproof membrane in place, and keep the weep holes clear with a few pebbles so water trapped in the mortar bed can still escape.

Maintenance That Prevents Backups

Drains clog from the top down. Hair, lint, and soap scum build a mat on the strainer, then sediment settles in the trap. A five-minute monthly routine keeps things flowing.

• Lift the strainer and clear visible debris by hand or with a bent wire.
• Flush with two gallons of hot water around 120°F to dissolve grease and soap film.
• Twice a year, pour a half cup of baking soda followed by white vinegar, wait 15 minutes, then flush.
• Avoid chemical drain openers in cast-iron bodies; repeated use can corrode the metal over time.

If water drains slowly even after cleaning the strainer, the clog is downstream and a hand auger fed through the cleanout will usually clear it.

What a Drain Project Typically Costs

A residential Zurn floor drain body runs roughly $40 to $150 depending on material and outlet size, with decorative grates adding $15 to $60. If you are pouring new concrete and can set the drain yourself, that is the whole parts bill. Retrofitting into an existing slab is where the cost climbs, since cutting concrete, tying into the waste line, and patching the floor often runs $400 to $1,200 in labor when hired out.

Spending a little more on the drain itself is almost always worth it. The body is buried in concrete, and replacing a failed cheap drain means breaking up the floor you just finished. Choose the right outlet size, add a trap primer if the drain will sit idle, and you have a fixture that protects your floor for the life of the home.