Our verdict
Pick the M63 for average water with a five-year limited warranty. Pick the M98 when you need 1/2 HP and about 23 ft of head for a high or long discharge.
The central trade-off
Power and head. The M98 is 1/2 HP with about 23 ft of maximum head.
Warranty. The M63 carries a five-year limited warranty; the M98's runs 12 months from installation or 18 from manufacture.
Shared features. Both are oil-filled cast iron with a snap-action switch, vortex impeller and 9 ft LED-plug cord.
Side by side
| Specification | Zoeller M63 Sump Pump | Zoeller M98 Flow-Mate Sump Pump |
|---|---|---|
| Horsepower | 3/10 HP | 1/2 HP |
| Max flow (maker) | 43 GPM | 72 GPM |
| Max head (maker) | Not stated by the maker | 23 ft |
| Switch | Not stated by the maker | Not stated by the maker |
| Housing | cast iron | Cast Iron |
| Discharge | Not stated by the maker | Not stated by the maker |
| Power cord | 9 foot cord | 9 foot cord |
| Weight | Not stated by the maker | 14.1 kg |
| Warranty | Not stated by the maker | 12 months from installation or 18 months from manufacture, whichever comes first |
Values are the makers' published specifications. "Not stated" means the maker doesn't publish it.