Wayne battery backup sump pump
Wayne offers two standalone battery backup pumps — the ESP25-N and WSM3300 — and one combo system (WSS30V) that pairs a 1/2 HP primary pump with the ESP25 backup in a single pre-plumbed unit.
The ESP25-N is Wayne's basic backup pump: 1,680 GPH at 10 ft, one battery, no self-test, 2-year warranty.[1] The WSM3300 adds an LCD display, 14-day automatic self-testing, and a phone-dialer for remote notification — all from a unit that claims 2,300 GPH at 10 ft.[3][4] Neither model publishes charger amps or the test condition for the GPH figures.
Wayne battery backup pump lineup
Flow figures are from Wayne's product pages and the ESP25-N manual. No test condition (battery voltage, battery age, or ambient temperature) is stated for any Wayne model.
Wayne backup pump comparison
| Model | Flow at 0 ft | Flow at 10 ft | Flow at 15 ft | Batteries | Notification | Self-test | Warranty |
|---|---|---|---|---|---|---|---|
| ESP25-N ESP25-N | 2,900 GPH | 1,680 GPH | 600 GPH | up to 1, sold separately | audible alarm | none | — |
| WSM3300 WSM3300 | 3,300 GPH | 2,300 GPH | 1,500 GPH | up to 1, sold separately | phone dialer | every 14 days | 2 yr |
| WSS30V WSS30V combo | 2,900 GPH | 1,680 GPH | 600 GPH | up to 1, sold separately | audible alarm | none | 5 yr |
ESP25-N — basic backup pump
The ESP25-N is a 12V submersible pump with a coated steel housing, stainless steel shaft, and thermoplastic impeller.[1] The manual describes it as "intended for use with one 12 V battery only" — no second battery port. The battery box accommodates up to a group 27 frame AGM battery.
There is no self-test, no display, and no notification beyond the audible alarm that sounds when the pump is running on battery. The manual does not specify charger amps — the charger is labeled "transformer" (part 30221-WYN1) in the parts list. The pump keeps running 20–25 seconds after the float drops to help prevent short cycling.
Warranty is 2 years from date of purchase from an authorized dealer.[1]
Flow at 10 ft: 1,680 GPH — this is the manufacturer's own manual figure. Retail listings occasionally show 3,300 GPH for the older ESP25; Wayne's manual for the ESP25-N shows 2,900 GPH at 0 ft and 1,680 GPH at 10 ft.[2]
WSM3300 — advanced notification backup pump
The WSM3300 sits in the same class as the ESP25-N but adds meaningful features: a built-in LCD display with programmable panel buttons, a 14-day automatic self-test of the float and pump,[4] and a phone-line auto-dialer.[3] The dialer calls up to three programmed phone numbers — your cell, a neighbor, or a plumber — when the backup pump activates, when a test fails, or when certain faults occur. An active standard telephone line is required; there is no Wi-Fi or app integration.
The published flow curve shows 2,300 GPH at 10 ft and 1,500 GPH at 15 ft. No test condition is stated. Wayne recommends the WSB1275 (75 Ah) battery. At 5 gallons per minute of incoming water with that battery, the manufacturer claims up to 26 hours of protection, though the test details are not fully published.
Warranty is 2 years. The WSM3300 is described as suited for finished basements and high-value storage areas where notification matters.[3]
WSS30V — combo system
The WSS30V pairs a CDU800 1/2 HP cast-iron primary pump with an ESP25 12V backup pump, both pre-plumbed with check valves and float switches.[5] The backup pump data on the product page matches the ESP25-N manual exactly (2,900 GPH at 0 ft, 1,680 GPH at 10 ft, 600 GPH at 15 ft), though the backup component is labeled "ESP25" without the -N suffix.
The primary pump moves up to 5,100 GPH at 0 ft and 3,840 GPH at 10 ft. Wayne claims up to 26 continuous hours of protection on the backup pump, but the complete test condition is not published. Alerts are audible alarm only — no phone dialer and no Wi-Fi. A 12V battery is required and sold separately.
The WSS30V carries a 5-year limited warranty, the longest in Wayne's sump pump line. It requires a pit at least 15 in. in diameter.
Battery compatibility
All three Wayne backup systems require a 12V battery, sold separately. Wayne recommends the WSB1275 (a 75 Ah maintenance-free AGM battery) for the WSM3300 and WSS30V. The ESP25-N manual specifies AGM batteries as preferred and accepts up to a group 27 frame size; wet-cell batteries are compatible but not listed as preferred.[1]
Charger amps are not published for any Wayne backup model. The ESP25-N manual refers only to a "transformer" accessory; the WSM3300 describes "smart charging technology" without specifying amperage. For comparison, Zoeller's Fit 508 publishes a 7 A charger amp rating, and Basement Watchdog's Big Dog CONNECT specifies 20 A.
Model confusion: ESP25 vs. ESP25-N
The ESP25 (without -N) is an earlier version. Some retail listings use the old name and show flow figures as high as 3,300 GPH — Wayne's own ESP25-N manual shows 1,680 GPH at 10 ft.[2] When comparing models, check the full part number (-N indicates the current revision). The WSS30V lists "ESP25" in its product page, but the published flow data matches the ESP25-N exactly.
How Wayne compares to other brands
Wayne is unusual in not publishing test conditions for any of its backup pump flow figures. Zoeller explicitly states it measures on a real 12V deep-cycle battery and warns that some manufacturers publish flow data at higher voltages or from bench tests that overstate performance by 40–80%. Without a stated test condition, Wayne's GPH figures cannot be directly compared to Zoeller's or Liberty's battery-based curves.
The WSM3300's phone dialer is a feature not found in most competing systems, which use Wi-Fi apps. If your basement has no Wi-Fi but does have a landline, the WSM3300 is the only major-brand backup pump with built-in phone notification.
See the backup sump pump pillar page for a cross-brand comparison, and the Zoeller and Basement Watchdog pages for those lineups in full.
Frequently asked questions
What is the difference between the Wayne ESP25-N and WSM3300?
The ESP25-N is a straightforward backup pump: 1,680 GPH at 10 ft, no LCD, no self-test, audible alarm only.[1] The WSM3300 adds a built-in LCD, a 14-day automatic self-test,[4] and a phone-line auto-dialer for up to three programmed contacts.[3] Both carry 2-year warranties.
Does the Wayne ESP25-N include a battery?
No. The ESP25-N ships without a battery. The manual calls for one 12V battery (AGM preferred, up to group 27 frame), sold separately. Wayne recommends the WSB1275 (75 Ah).[1]
What is the Wayne ESP25 versus the ESP25-N?
The ESP25-N is the current production model. Earlier retail listings under the ESP25 name sometimes show 3,300 GPH; Wayne's ESP25-N manual gives 1,680 GPH at 10 ft.[1][2] Check the full model number when ordering parts or comparing specs.
Does the Wayne WSM3300 have Wi-Fi?
No. The WSM3300 uses a phone-line dialer that calls up to three programmed numbers. A standard telephone line is required. No Wi-Fi module or app is listed for the WSM3300.[3]
What does the Wayne WSS30V combo include?
The WSS30V includes a CDU800 1/2 HP primary pump and an ESP25 12V backup pump, both pre-plumbed with check valves and float switches. Battery (sold separately) and installation materials are not included. The system carries a 5-year limited warranty.[5]
Sources
- ESP25-N Operating Instructions and Parts Manual (600001-001 B) — WAYNE / Scott Fetzer Company, document dated 2018-08. Accessed 2026-11-03. Manufacturer manual hosted by Home Depot.
- Wayne ESP25 product listing — PlumbersStock. Accessed 2026-11-03.
- WSM3300 12-Volt Battery Back-Up Sump System product page — WAYNE / Scott Fetzer Company. Accessed 2026-11-03.
- WSM3300 Battery Back-Up Systems specification sheet — WAYNE / Scott Fetzer Company, document dated 2016-05. Accessed 2026-11-03. Manufacturer spec sheet. Shows 14-day self-test interval and performance curve.
- WSS30V 1/2 HP Sump Pump with Battery Backup product page — WAYNE / Scott Fetzer Company. Accessed 2026-11-03.