Attwood Marine Shower Sump Replacement Box, for 500 GPH Sump

Overview

The Attwood Marine 914087 is a shower sump box assembly for moving gray water from a boat shower and other onboard drains at up to 500 GPH on a 12V DC system. It suits installations where you need a compact sump under the sole, in a head compartment, or in another low point that can collect drain water before discharge overboard.

This 500 GPH version uses a 3/4 in. I.D. outlet and a 3-amp fuse, and it fits the standard Attwood sump box size at about 10-1/2 in. long, 8-1/8 in. wide, and 4-1/2 in. high. The box includes an air vent to help prevent air locks, and the lid can be opened for filter inspection and cleaning.

It is a good fit for boats that route shower water, head sink water, or other gray-water drains into one collection box before pumping out. On smaller cruisers, fishing boats with a compact head, and sailboats where space is tight, those fit details matter more than headline flow numbers.

Key features

• 500 GPH gray-water sump capacity for shower and other drain outlets
• 12V DC operation with a 3-amp fuse requirement
• 3/4 in. I.D. outlet connection for discharge hose routing
• Standard box footprint at about 10-1/2 in. x 8-1/8 in. with a height of about 4-1/2 in.
• Air vent built into the box to reduce air-lock problems in the drain line
• Lid opens for filter access, inspection, and routine cleaning
• Supports more than one drain connection when the installation calls for multiple inlets

Installation and setup

The box should be mounted lower than the shower pan and any other drains feeding it, and it needs to sit level so the sump can cycle properly. Leave enough side and top clearance to remove the lid and service the filter.

For discharge plumbing, the outlet hose should rise smoothly from the sump to the thru-hull with no dips in the run. On the inlet side, hoses should also rise cleanly from the sump fittings up to the drains. That layout helps the box clear water properly and avoids the air-lock and backflow issues that show up in cramped installations.

Compatibility and fit

Before ordering, check that your boat uses a 12V DC system, that you have room for the standard box dimensions, and that your discharge plumbing is set up for a 3/4 in. I.D. outlet hose. This style of sump makes sense where shower water needs to be collected below the drain level and pumped out rather than drained directly overboard.

On sailboats, placing the sump close to the centerline helps it stay in a better working position when the boat heels. On powerboats, it is a good fit for compact heads, mid-cabin cruisers, and other layouts where the sump has to live in a tight locker or under a sole panel but still remain accessible for cleaning.

Orders are processed within 2 business days, which includes verification, packing, and dispatch. Orders of $100 or more qualify for free shipping when eligible. For orders under $100, shipping costs are calculated at checkout based on destination, package weight, and selected service. International shipping is available for eligible products, and certain items may require additional handling, warehouse transfers, or may ship directly from the manufacturer, which can affect processing time.

Deliveries are handled by preferred carriers such as USPS, UPS, FedEx, DHL, and others depending on your location and selected service. Estimated delivery times are displayed at checkout and may vary due to customs processing, carrier delays, weather, postal disruptions, or other circumstances beyond our control. Once your order ships, you'll receive a confirmation email with tracking information. Tracking may take up to 24 hours to update on the carrier's website and is also available through your account when applicable.

We ship throughout the United States and to most international destinations for products eligible for international shipping. International orders may be subject to customs duties, taxes, brokerage charges, or other import fees, which are the customer's responsibility and are not included in the product or shipping price. PO Boxes are accepted only when shipping through USPS, and not all packages qualify for this option. If your order does not arrive within the estimated delivery window, please contact us at info@apollolighting.com or +1 (954) 375-0100 so we can assist with locating your package.

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Returns may be requested within 30 days of receiving your order. Items must be unused, uninstalled, unaltered, and returned in their original packaging with all tags, packing materials, blank warranty cards, manuals, instructions, accessories, and included items. Certain products, including installed or used electronics, electrical components, lighting, consumables, custom or special-order items, cut-to-length products, safety equipment, and merchandise exposed to water or marine conditions, may not be eligible for return.

To request a return, sign in to your account and select the applicable order and items, and submit your request for review. Eligible unfulfilled items may also be submitted for cancellation within 1 hour of placing the order. Returns or cancellations are not considered approved until you receive confirmation from Apollo Lighting. Please do not ship or drop off merchandise before receiving return approval and instructions.

Customers are responsible for arranging and paying for return shipping unless the return is due to an error by Apollo Lighting or the item is verified as defective, damaged, or incorrect. Missing, damaged, defective, or incorrect items must be reported within 2 business days of delivery, and photos or other documentation may be required for review. If the issue is verified, Apollo Lighting may provide or reimburse return shipping and issue a replacement or refund depending on the circumstances. International customers are responsible for return shipping, duties, taxes, customs charges, brokerage fees, and other costs associated with an international return.

After your return is received and inspected, approved refunds are issued to the original payment method and may take 5-7 business days to appear after processing. Original shipping and handling charges are nonrefundable, and the value of any included free items that are not returned may be deducted from the refund. Apollo Lighting does not charge a standard restocking fee on eligible returns. Returns that are incomplete, damaged, installed, used, altered, improperly packaged, or otherwise do not meet the eligibility requirements may be refused. We recommend using a trackable and appropriately insured shipping service for all customer-arranged returns.

For assistance, contact info@apollolighting.com or call +1 (954) 375-0100.

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Many products sold by Apollo Lighting include a manufacturer's warranty covering defects in materials or workmanship. Warranty terms vary by brand, product category, and model, so eligibility, coverage duration, exclusions, and available remedies are determined by the applicable manufacturer. We recommend reviewing the warranty information provided with your product before installation or use, especially for marine electronics, navigation equipment, lighting, electrical systems, pumps, safety equipment, and other specialized marine products.

If you need warranty service, the claim must follow the process established by the manufacturer, authorized service center, or designated warranty provider. You may be asked for proof of purchase, a serial number, product registration, photos, maintenance or installation records, or other documentation. Apollo Lighting does not determine or modify a manufacturer's warranty coverage or final claim decision, but we are happy to help provide purchase information and direct you to the appropriate manufacturer or warranty resource.

Keep your receipt, product documentation, serial number information, and original packaging when practical. Damage caused by normal wear, misuse, improper installation, insufficient maintenance, corrosion, impact, unauthorized modifications, electrical issues, or operation outside the manufacturer's specifications may not be covered. Warranty claims are separate from standard returns, so a product that has been installed, used, or exposed to marine conditions may no longer qualify for return while still remaining eligible for evaluation under the manufacturer's applicable warranty.

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