A sewage ejector pump sits in a sealed basin below the basement floor, collects waste from a bathroom or laundry that cannot drain by gravity, and pumps it up into the main sewer line. It handles solids up to 2 inches, needs its own vent, and is sized by the fixtures it serves and the height it has to lift.
Plumbing Picks is reader-supported. As an Amazon Associate, we earn from qualifying purchases at no extra cost to you.
Our pick: the Zoeller M267 Waste-Mate. Check the Zoeller M267 on Amazon
This guide is part of our complete drain & waste-line resource.
If you’ve got a bathroom, laundry, or wet bar below your home’s main sewer line, you need a sewage ejector pump to lift that wastewater up and out. I’ve installed and replaced a lot of these over the years, and the difference between a good pump and a cheap one is the difference between forgetting it exists and getting a 2 a.m. backup in a finished basement. Here are the three I actually trust, plus how to size and install one the right way.
Not sure which pump your situation needs? Ejector vs sump pump.
What Is a Sewage Ejector Pump?
A sewage ejector pump is a solids-handling pump that lives inside a sealed basin set into the basement floor, below the level of the gravity sewer. Waste from a below-grade toilet, shower, laundry or wet bar drains into that basin; a float switch starts the pump when the level rises, and the pump lifts everything up a discharge pipe into the main drain. The International Plumbing Code section 712.2 requires both a check valve and a full-open valve on that discharge line, with access to both, so nothing runs back into the pit.
What Is an Upflush Toilet?
An upflush toilet is a macerating toilet system, and it does the same job from above the slab. The unit sits on the floor instead of under it, macerates what the bowl sends it, and pumps that out to the gravity drain — so no one breaks concrete. On a finished basement that is usually the deciding factor. The IPC treats these as their own class of equipment: section 712.4.1 requires a macerating toilet system to comply with ASME A112.3.4/CSA B45.9 and to be installed in accordance with the manufacturer’s instructions. I compare the two directly in upflush toilet vs sewage ejector pump.
Best OverallEditor’s Choice
Zoeller M267 Waste-Mate Sewage Ejector Pump
The Zoeller M267 is the pump I reach for first on a basement bathroom. Zoeller’s technical data sheet for the Waste-Mate 266/267 (document FM2789) rates it at 1/2 HP with 2-inch spherical solids handling and a 2-inch NPT discharge, lists the cap, motor housing, pump housing and base as cast iron, and gives the cooling as oil filled. The switch is an integral float-operated mechanical switch, so there is no external control to source.
Two figures off that sheet decide whether it suits your pit. Zoeller’s minimum recommended simplex basin for the 267 is 18 by 30 inches, and its published curve gives 115 gpm at 5 feet of head, 85 at 10 feet and 45 at 15 feet, against a shut-off head of 20.5 feet. If your discharge has a long climb before it turns horizontal, that fall-off is the reason to read the Liberty below.
👉 Check the Zoeller M267 Waste-Mate on Amazon
1/2 HP · passes 2-inch solids · cast-iron body
- Passes 2-inch solids for a full basement bathroom
- Tough cast-iron build
- Trusted name in sewage pumps
- Needs a properly vented, sealed basin
- Heavy to set in the pit
- 2-inch discharge, so 1-1/2-inch sump-pump fittings will not fit
Verdict: The workhorse for a basement bathroom done right.
If the M267 listing shows out of stock, Amazon also lists the Waste-Mate 267 as Zoeller part number 267-0001, which the listing gives as the 1/2 HP automatic version with an integral float switch. Zoeller builds the 267 in several voltage, switch and cord-length options, so match the part number to your power supply and switch type before you order.
Best High-Flow Value
Liberty Pumps LE51A
Liberty’s LE51A moves more water at height than the Zoeller, which is why it is the pick when the basin has a long climb to the sewer or more than one fixture feeding it. Liberty’s LE50-Series sales sheet states 118 GPM at 10 feet of total dynamic head and a 25-foot maximum head; the engineering specification adds a shut-off head of 24 feet and a maximum flow of 141 GPM at 5 feet of total dynamic head.
The rest of it is built for service rather than for the shelf: Class 25 cast iron volute and motor housing, an oil-filled hermetically sealed motor, a two-vane semi-open impeller that passes a 2-inch spherical solid, a stainless shaft and stainless hardware, and a quick-connect 10-foot cord you can change without breaking a seal to the motor. Liberty’s published standard limited warranty on the series is three years.
👉 Check the Liberty Pumps LE51A on Amazon
1/2 HP · high GPM · reliable build
- Strong flow at a fair price
- Dependable for longer runs to the main
- Good Liberty Pumps reliability
- No basin or cover — the wide-angle float switch is included, the pit is not
- Verify your discharge pipe size
- Still needs proper venting
Verdict: The value pick when you need flow more than frills.
Best Complete System
Liberty Pumps P382LE41 Basin Package
If you don’t already have a basin, don’t piece it together — buy a pre-assembled system. The Liberty P382LE41 comes as a sealed 41-gallon basin with the pump, float, and gasketed cover already installed and ready to set. It runs a 4/10 HP pump and is sized for a typical single below-grade bathroom. Buying the basin and pump as a matched, factory-sealed unit saves you hours and — more importantly — avoids the sewer-gas leaks that come from a poorly sealed DIY basin lid. This is what I’d put in a new basement bath.
👉 Check the Liberty Pumps P382LE41 basin package on Amazon
Pre-assembled basin, pump and sealed cover kit
- Basin, pump and sealed cover in one package
- Saves sourcing every part separately
- Faster, cleaner install
- Most expensive option upfront
- Bulky to move and set
- Still needs proper venting and a check valve
Verdict: The grab-it-all system when you are building the pit from scratch.
Best Grinder Pump
Zoeller Shark 807 Grinder Pump
A grinder is the tier above an ejector pump, and it earns its keep only when the discharge has somewhere hard to go — a long horizontal run, a steep lift, or a low-pressure sewer main. Zoeller’s product page for the Shark Series Model M807 (product SKU 807-0001, the model number on the listing) gives it as a 1 HP, 115-volt, single-phase automatic grinder drawing 11.0 amps at 3400 rpm, with a 1-1/4-inch NPT discharge and a 15-foot cord.
Its Tri-Slice cutter runs three cutting channels and reduces solids to 1/8 inch, which is what lets that narrower discharge work. Zoeller lists the switch case, motor housing, pump housing and base as cast iron, the float guard, handle, switch arm and hardware as stainless steel, and publishes a three-year limited warranty on the pump at the time of writing (September 2026). For an ordinary basement bath draining to a gravity sewer you do not need this — read the grinder-versus-ejector section above before you spend.
👉 Check the Zoeller Shark 807 grinder pump on Amazon
1 HP · 115 V · 1-1/4-inch NPT discharge · cast-iron body
- Tri-Slice cutter reduces solids to 1/8 inch
- 1-1/4-inch discharge suits a long, uphill or pressurised run
- Cast-iron housings with stainless hardware
- More pump than an ordinary basement bathroom needs
- 1-1/4-inch NPT discharge, so 2-inch ejector fittings will not fit
- Still needs a sealed, vented basin and a check valve
Verdict: The step up when the run to the sewer is long, uphill or pressurised.
Best Ejector Pump for a Basement Bathroom
For one below-grade bathroom, the Zoeller M267 Waste-Mate is the ejector pump to buy: 1/2 HP, cast iron, and it passes the 2-inch solid the code demands of any pump taking a toilet’s discharge. Choose the Liberty LE51A instead when the discharge climbs a long way or more than one fixture feeds the pit.
What size ejector pump do I need for a basement bathroom?
For one below-grade bathroom, a 4/10 to 1/2 HP pump that passes a 2-inch solid is the right size. The International Plumbing Code requires that solids capability of any pump taking a water closet’s discharge, and its Table 712.4.2 sets the floor at 21 gpm on a 2-inch discharge pipe.
Grinder pump or ejector pump for a basement bathroom?
For a basement bath draining to a gravity sewer, an ejector pump. It passes a 2-inch solid whole, as the code requires. A grinder cuts solids to a slurry so they can travel further or enter a pressurised main; the IPC lets a grinder’s discharge opening drop to 1-1/4 inches. Pay for that only if your run needs it.
How big does the basin have to be?
The IPC sets the floor at 18 inches in diameter and 24 inches deep, fitted with a gastight removable cover no more than 2 inches below floor level. Manufacturers publish their own minimums on top of that: Zoeller’s data sheet asks for an 18-by-30-inch simplex basin behind the M267. Buy the basin to suit the pump, not the hole.
Does an ejector pump basin have to be vented?
Yes. The IPC requires the sump pit be vented in accordance with Chapter 9 and that its cover be gastight. It also requires the float be set so effluent never rises within 2 inches of the invert of the gravity drain coming into the pit. Skip either and you get sewer gas in a finished room.
How to Install a Sewage Ejector Pump (Overview)
- Turn off power to the circuit and confirm it’s dead before touching anything.
- Set the sealed basin in the floor pit, level, with the inlet lined up to your drain stub.
- Connect the gravity drain line to the basin inlet using a rubber coupling.
- Install a check valve on the discharge pipe so wastewater can’t flow back into the basin, and a full-open valve above it — the IPC requires both, sited so you can get at them.
- Run the discharge line (usually 2-inch) up and tie into your sewer or septic line above the pump.
- Vent the basin — this is required by code and keeps the pump from air-locking and sewer gas out of the room.
- Seal the basin cover with its gasket so no gas escapes, then plug in the pump and float on a dedicated GFCI circuit.
- Test it: pour water into the basin until the float trips and confirm the pump cycles on, pumps down, and shuts off cleanly.
Most jurisdictions require a permit and a proper vent tie-in for sewage ejectors. If the discharge tie-in or venting is over your head, this is one worth handing to a licensed plumber — a leak here is sewage, not clean water.
Step 4 is worth a moment, because size decides it: a sewage discharge line is normally 2-inch, so the 1-1/2-inch check valve that fits most sump pumps will not fit this one. The IPC also wants a full-open valve on the discharge side of the check valve, with access to both.
A cast-iron, full-flow valve with slip-on unions, such as the Zoeller 30-0151, clamps onto PVC or ABS with stainless clamps and no threading, and the unions let you take it apart to pull the pump years later without cutting the discharge pipe. If you are dropping a new pump into a system that already has a sound check valve in the line, you do not need a second one — measure the pipe you actually have before you buy either way.
FAQ
What is the difference between a sump pump and a sewage ejector pump?
A sump pump moves clean groundwater out of a pit to keep your basement dry. A sewage ejector pump moves wastewater and solids from a below-grade bathroom, laundry, or kitchen up to your main sewer or septic line. They are not interchangeable — an ejector pump is built with a larger impeller to pass solids (typically up to 2 inches), while a sump pump will clog if you run sewage through it.
What size sewage ejector pump do I need for a home bathroom?
For a single below-grade bathroom, a 4/10 HP to 1/2 HP pump that passes 2-inch solids is plenty. Step up to 3/4 HP or higher only if you have a long vertical run, multiple fixtures, or a long horizontal pipe to the sewer. Size on the head your discharge actually has, not on horsepower alone — read the pump’s curve at your lift.
How long should a sewage ejector pump last?
A quality cast-iron pump like a Zoeller or Liberty usually lasts 7 to 10 years, sometimes longer. The float switch is the part that fails first. Test the pump a couple of times a year by pouring water into the basin until it kicks on, and never flush wipes, grease, or hygiene products — those are what kill ejector pumps early.
Bottom Line
For most homeowners, the Zoeller M267 Waste-Mate is the safe, buy-it-once choice. If you’ve got a long lift or multiple fixtures, the Liberty LE51A gives you more flow for the money. And if you’re starting from scratch with no basin, the Liberty P382LE41 pre-assembled system is the cleanest, most leak-proof way to do it. Whatever you choose, stick with cast-iron and a name brand — a sewage pump is the last place to save twenty bucks.
Related Plumbing Guides
#ad Buying for a shop? Amazon Business (opens in a new tab) accounts are free to create, with business-only prices and bulk quantity discounts.
- Best Sump Pump
- Best Sump Pump Battery Backup
- Sump Pump Not Working? Causes & Fixes
- How to Unclog a Drain
Fix the 12 Most Common Plumbing Problems Yourself — Free Plumber’s Handbook
Step-by-step fixes for the 12 most common problems — and exactly when to call a pro. Free and instant, from a licensed plumber. Save hundreds on calls you didn’t need.