SKU: 12746144903

Promaster Undermount Water Tank (15 Gallon)

Sale price$116.55 Regular price$129.50
Save 10%

Pay in installments of $32.38 with ShopPay, AfterPay and Klarna

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Aug 13 - Aug 18

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

Promaster Undermount Water Tank (15 Gallon)We are always striving for better space saving ideas, and this undercarriage tank is just the ticket! This tank is designed to fit snugly around your Promasters framed undercarriage; these tanks are the perfect solution for your off grid water requirements. Composed of high quality, BPA free, food grade approved linear low density polyethylene, this tank can also function as freshwater storage. We've created a complete Freshwater Fittings Kit that

We are always striving for better space-saving ideas, and this undercarriage tank is just the ticket! This tank is designed to fit snugly around your Promaster’s framed undercarriage; these tanks are the perfect solution for your off-grid water requirements.

Composed of high-quality, BPA-free, food-grade approved linear low-density polyethylene, this tank can also function as freshwater storage. We've created a complete Freshwater Fittings Kit that includes everything you need to turn this tank into an undermount freshwater reservoir. 

Complete your off-grid water management system by pairing this undermount tank with our 22 Gallon, or our 32 Gallon Promaster Wheel Well Water Tank. Worry less about water management, and spend more time adventuring!

Key Features & Benefits:

  • Save Space - Mount underneath your van chassis for extra storage room inside your van - passenger side only.
  • Perfect Fit - Designed to fit perfectly under the Promaster van, simply position the tank and attach with strapping, no need to make modifications.
  • Durable Design - This tank is tough; rest assured knowing your tank will hold up to exposure and the elements.
  • Multi-Purpose - Use this undermount tank for grey water storage, or bundle it with our Freshwater Fittings Kit and turn this tank into a freshwater reservoir.
  • BPA-Free and Food Grade Approved - These tanks are CSA approved and food grade certified for safe drinking water.
  • Fittings Kit Add-On Available - Save yourself the headache and multiple trips to the plumbing store when you bundle this tank with our Grey Water Fittings Kit or Fresh Water Fittings Kit!
  • Strapping Kit Add-On Available - Weather-resistant strapping crafted from heavy-duty 1/8" thick, 1 1/2" wide aluminum. Simple and secure! 
  • Compatible - This tank pairs well with our 22 Gallon and 32 Gallon Promaster Wheel Well Water Tanks.

Dimensions & Specifications:

Designed for the Ram Promaster 159" & 159" extended wheelbases.
NOT COMPATIBLE with the 118" or 136" wheelbase.

The tank can only be mounted on the PASSENGER SIDE of your van.
However, your drain hose can be routed to your drivers side if needed.

Tanks are made from linear low-density polyethylene.
Food grade CSA approved and BPA free - safe for freshwater use!

15 US Gallons / 56.7 Litres

45.5" x 13 3/8" x 8" (Length x Width x Height)

1 x 1 ¼" fill port (on right side)
1 x ¾" drain port (on right side)
2 x ½" vent ports (on left side, top of humps)
1 x ½" vent port (on front end, top of hump)
1 x ½" optional water-pump port for freshwater use (on front end, bottom corner)

All ports are NPT female-threaded.

Grey Water Fittings Kit Add-On:

  • 1x 1 ¼" PVC 90
  • 2x ¾" PVC 90
  • 1x ¾" PVC Ball Valve
  • 1x ¾" Nipple - 6" long
  • 1x ¾" Nipple - 4" long
  • 1x ¾" Nipple - 1 ½" long
  • 3x ½" Poly Adaptors
  • 1x ½" Poly Elbow
  • 1x ½" PVC Plug
  • 2x #20 Hose Clamps
  • 3x #8 Hose Clamps
  • 1x Roll of Teflon Tape
  • 5ft Fill Hose
  • 2ft ⅝" ID Vinyl Hose

Fresh Water Fittings Kit Add-On:

  • 1x 1 ¼" PVC 90
  • 2x ¾" PVC 90
  • 1x ¾" PVC Ball Valve
  • 1x ¾" Nipple - 6" long
  • 1x ¾" Nipple - 4" long
  • 1x ¾" Nipple - 1 ½" long
  • 3x ½" Poly Adaptors
  • 1x ½" Poly Elbow
  • 1x ½" PVC Plug
  • 2x #20 Hose Clamps
  • 2x #8 Hose Clamps
  • 1x Roll of Teflon Tape
  • 1x Fill Port
  • 5ft Fill Hose
  • 5ft ⅝" ID Vinyl Hose

Aluminum Strapping Kit Add-On:

  • 2x Heavy-Duty Aluminum Straps
  • Aluminum Hardware

More Information:

Wheel Well & Undermount Water Tank FAQ Sheet

Full Details of the Grey Water Fittings Kit Add-On
Select this add-on with your tank purchase and save $$ vs buying separately!

Full Details of the Fresh Water Fittings Kit Add-On
Select this add-on with your tank purchase and save $$ vs buying separately!

Full Details of the Aluminum Strapping Kit Add-On
Select this add-on with your tank purchase and save $$ vs buying separately!

Check out our Promaster Wheel Well Water Tank (22 Gallon)

Check out our Promaster Wheel Well Water Tank (32 Gallon)

Install Instructions:

Freshwater Fittings Kit Install Instruction
Grey Water Fittings Kit Install Instructions
Strapping Kit Install Instructions for Promaster 15 Gallon Water Tank (Passenger Side)

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 12746144903

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.2 ★★★★★
Based on 11 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
D
Verified Purchase
D.B. Spalding
Alexandria, US
★★★★★ 4
Great tool, but be careful when you replace a needle.
Size: 2.0, Size: 2.0
Great idea, you can arrange the needles in either direction, depending upon the direction that you move the tool (clockwise, or anti-clockwise). But be VERY CAREFUL in dismantling, as it may come apart on you, spilling needles. Getting the needles lined up takes time and patience. Replacing one by itself should be easier. 3BOMBER would do well to include an exploded view of this tool in the instructions so owners know what to expect. That said, this works great, and the magnetic attachment to the stand is very convenient — easier than a stand with a hole in it. Also, the flat top lets you set it upside down in a jiffy. Definitely recommended.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on November 26, 2024
P
Verified Purchase
pvinthebay
Lowell, US
★★★★★ 5
Makes all the difference in your extraction.
Size: 2.0, Size: 2.0
This little guy improved the extraction quality without being overly complex. After grinding there were always high spots in the porta filter when I put the grinds in. There are several different ways to distribute the grinds and I found this to be simple and effective without breaking the bank. The weight is nice and comes with extra pins just incase you bend yours. I've had mine for over a year and haven't needed it so it's nice that it's available. Simple practical tools like this are great in the setup and show you don't need to break the budget to have a solid coffee setup. I enjoy the 3BOMBER line of tools. For the money they offer the best value
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on July 27, 2025
J
Verified Purchase
J D
Lake Worth, US
★★★★★ 5
Meh
Size: 2.0
I don't use it because I found it unnecessary. I'm not a pretentious coffee aficionado fanatic tho. It's great quality and highly engineered tho 🦾
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 26, 2026
T
Verified Purchase
Tickerguy
Carnegie, US
★★★★★ 5
Nicely built, does the job, the stand is an excellent add
Size: 2.0
Its a WDT tool; that and a magnetic funnel for the basket are sort of "the deal" for getting an even distribution in your portafilter to resolve channeling issues. Its the proper size for E61 and similar-sized espresso machines and thus is compatible with basically all but the small "economy" units; for those you probably want something with less "splay" on the needles. The material and design make it "knock it on the side of the counter" easy to keep clean and the magnetic stand means its right there and won't get damaged. For relatively small money it doesn't get better than this in doing the job. Recommended.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 30, 2026
J
Verified Purchase
Jeff S
San Leandro, US
★★★★★ 5
Works Great - Better results With Shot
Color: Matte Black
Very happy with the tool. My first experience using a WDT tool. Really helped my shot quality. I like the stand it comes with. I don't find it that hard to place back in the stand. If anything a slight inward push on the needles and goes in. The number of needles make it easy to use. The size is convenient for use and doesn't take up much room. I keep it next to my grinder. The extra needle set is great. Highly recommend.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 12, 2025

recommand products