Seaward S1100 Marine Water Heater — 11 Gal, 120V AC, Rear Heat Exchanger (698-S1100)
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
Serious Hot Water Capacity for Larger Vessels
The Seaward S1100 (698-S1100) is an 11-gallon marine water heater built for cruisers, liveaboards, and larger power vessels where a 6-gallon unit simply won't keep up. The rear-mounted dual-wall heat exchanger integrates with your engine's coolant loop so you're building hot water reserves while underway — arriving at anchorage with a full tank ready to go.
Key Features
- 11-Gallon Capacity — handles the hot water demands of larger crews and extended passages
- 120V AC / 1800W — shore power compatible for marina and dock use
- Rear-Mounted Dual-Wall Heat Exchanger — engine coolant loop integration for efficient underway heating; rear placement suits most engine room plumbing layouts
- Aluminum Tank — lightweight, corrosion-resistant; hold-down brackets welded directly to tank for rigid, vibration-proof mounting
- Galvanized Steel Case — durable exterior for bilge or locker installation
- Ignition Protection — safe for installation aboard gasoline-engine vessels
- UL Certified — meets US safety standards for marine electrical appliances
Parts Desk Insights
SKU 698-S1100 is the 11-gallon rear-exchanger variant in the Seaward line, sourced through Land 'N' Sea under the Whale/Seaward brand. Key differentiator from the F600 (698-F600): this unit uses a rear heat exchanger vs. the F600’s front-mounted configuration — confirm engine room layout and hose routing access before recommending one over the other. At 15.4 kg, this is a two-person install; flag for freight or special order lead time if not in local stock. No image currently on file — flag for photo or manufacturer asset request.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.