Zoeller Sump Pump Model Numbers: M53, M57, M63, M98 and Item Numbers Explained

When you replace a Zoeller Model 53, 57, 63 or 98 sump pump, two numbers matter: the model, such as M53, N98 or BN98, and the item number, such as 98-0001. Here is what each one means in Zoeller's own documents, which printed specifications to compare, and where to find them.

Where to find your Zoeller model number

To order replacement parts, Zoeller's parts lists ask for the model number, the part number of the pump, and the part number and description of the part. The parts lists refer to the model number and the date of manufacture on the pump's ID tag, and the installation instructions to the voltage and current on the nameplate.

Model letters: M53, N53, BN98 and the others

Zoeller's parts lists name the versions M53 automatic 115V, D53 automatic 230V, N53 nonautomatic 115V and E53 nonautomatic 230V; the Model 57 and 98 lists use the same letters. The model comparison charts in the technical data sheets for the Models 53 and 57 (FM2778) and 98 (FM2779) add BN and BE:

For the automatic models, the selection guides describe an integral float-operated mechanical switch with no external control required. For the nonautomatic models they point to a piggyback variable level float switch or other external controls, and the catalog says these switches convert a nonautomatic pump to automatic. According to the data sheets, BN and BE models include a piggyback variable level pump switch (20 ft on the BN98 and BE98). The Model 63 is listed only as the M63: automatic, 115 V.

The model can also carry a revision letter after a dash, such as M53-D. The parts lists split the parts by revision and date: the M53 list runs from M53-A (9/81 to 8/86) to M53-D (7/92 to current), and Zoeller's parts website asks you to select the revision code from your pump tag. If an X follows the model number or the date of manufacture on the ID tag, the parts lists say to consult the factory.

Item numbers such as Zoeller 98-0001

Zoeller's catalog labels the automatic Model 98 shown as 98-0001, and Zoeller's sheets list the M53 as 53-0001 and the BN53 as 53-0083. On Zoeller's product pages the item number appears as the Product SKU once you choose voltage, operation, switch and cord length. Examples from the Model 98 page, all 115 V:

The first two differ only in cord length, so match the full item number, not only the model letters. Backup packages have their own numbers, such as 508-0016 for the Aquanot 508 with Z Control and an M98 in the catalog.

Zoeller M53, M57, M63 and M98 specifications

The 53 and 57 are cast iron Mighty-Mate pumps (the 55 and 59 are bronze), the 98 is a Flow-Mate pump, and the catalog describes the 63 as a Premium Series pump based on the 50 series. Printed specifications for the automatic 115 V versions:

At 10 ft of total dynamic head the data sheets print 34 GPM for the 53, 57 and 63 and 61 GPM for the 98. All four have a 1-1/2 inch NPT discharge, and the data sheets give 1/2 inch spherical solids handling. For the built-in switch they print on and off points of 7-1/4 and 3 inches (53, 57, 63) and 9-1/2 and 3 inches (98). The 53, 57 and 98 data sheets list 9 ft cords for automatic and 15 ft cords for nonautomatic models and say additional cord lengths are available. The M63 data sheet lists a 9 ft cord.

FM2778 describes the Model 53 with a cast iron switch case, motor and pump housing and a plastic impeller and base, and the Model 57 as all cast iron with a cast iron impeller. The M63 data sheet lists a cast iron switch case, motor and pump housing, impeller and base.

1/2 HP or 3/10 HP?

Zoeller prints 3/10 HP for the 53, 57 and 63 (0.30 HP on its product pages). Where a listing differs, go by the data sheet. Of these four models, the 1/2 HP Zoeller sump pump is the Model 98.

What to compare before you order a replacement

• Model and letters: automatic or nonautomatic, 115 or 230 V
• Switch: built-in float switch (M, D), piggyback switch included (BN, BE) or external switch or control (N, E)
• Horsepower from the data sheet; voltage and current from the nameplate
• Discharge size and cord length
• Flow at your head from the performance table, not only the maximum figures
• Materials of the impeller and base

Zoeller's product pages for the Model 53, Model 57, Model 63 and Model 98 link the technical data (spec) sheet (FM2778 for the 53 and 57, FM2899 for the 63, FM2779 for the 98), parts list, installation instructions and performance curve.

The data sheets say that controls, protection devices and wiring should be installed by a qualified licensed electrician, following all electrical and safety codes. Install a replacement according to Zoeller's instructions and your local codes.

Zoeller sump pump parts

The parts lists help you identify a part: the case and switch assembly 004702 is listed for the current revisions of the M53, M57 and M98, while the M53-A lists 054051. The catalog lists the 10-0055 as a 115 V single piggyback variable level float switch with a 10 ft cord, for basins at least 18 inches in diameter.

Zoeller sump pumps at The Builders Supply

• Zoeller - all Zoeller products, and the pumps, water heaters and ventilation category
• Model 98: 98-0001 (M98), 98-0002 (N98), 98-0005 (BN98)
• Models 53, 57 and 63: 53-0001 (M53), 57-0001 (M57), 63-0001 (Model 63)
• Parts: 004702 case and switch, 10-0055 piggyback float switch

Not sure which Zoeller pump or part matches yours? Our customer support team is available Monday - Friday, 8 AM - 4 PM Central Time, at 1-888-800-7789 or [email protected].