Promaster Undermount Water Tank (15 Gallon)
SKU: 12746144903

Promaster Undermount Water Tank (15 Gallon)

Sale price$116.55 Regular price$129.50
Save 10%

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 6 - Jul 11

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

4.4 ★★★★★
Based on 356 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
C
Verified Purchase
Christy Sharp
Fort Morgan, US
★★★★★ 5
Durable
Style: Black chew toys for dogs
My hound dog seems to like hers. She greets me at the door every day with it in her mouth and she hasn’t been able to tear it up or get any little pieces in her mouth when she nib nibs on the edges. It doesn’t have a smell. It is hard. It seems safe I guess since they can’t pick it up with their paws and pop each other over the head with it but if you have an intruder it would be great to have in hand.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 20, 2026
D
Verified Purchase
DIGGER
Pawtucket, US
★★★★★ 5
Tough product
Style: Black chew toys for dogs
Received a timely manner and so far my puppy has no destroyed it yet, although he did his best to. Good product
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 12, 2026
W
Verified Purchase
Wolfpack Athletics
Waukegan, US
★★★★★ 5
Surprisingly Tough Without Being Too Hard
Style: Black chew toys for dogs
The hardness on this bone is right in the sweet spot for aggressive chewers. It’s firm and durable enough that my dog hasn’t been able to tear chunks off or destroy it quickly, but it’s not rock-hard to the point where I’d worry about teeth damage. My dog usually goes through most toys pretty fast, and this one has held up really well. After extended chewing sessions, it only shows minor wear instead of deep cracks or breakage. It keeps his attention without splintering or becoming unsafe. If you’re looking for a bone that can handle strong jaws while still being safe for aggressive chewers, this one strikes a good balance and has been a solid option so far.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 2, 2026
S
Verified Purchase
Sarah G
Alexandria, US
★★★★★ 4
Not completly indestructible but good buy
Style: Black chew toys for dogs, Style: Black chew toys for dogs
Dogs loved this. I have 5 pot mixed and they all have enjoyed this. I ordered two more after they enjoyed the first one so much. So far my dogs have not been as destructive as they have been in the past (especially on my couches). I have been home more recently so it could be a combination, but I think the bones have been helpful. Sturdier than the red Kong toys, but not as indestructible as the black kongs. As durable or more than the ruff dawg balls, and much more affordable than all of those. Also, some of my dogs are more selective on toys, but this one was an immediate hit, even with my dog that has shown now interest in ANY chew toy. We even walked through pet smart one day, and i tried to get him to play with every toy on the shelf- and he was not impressed. I even showed him the scented toys that cost $40-50 each. Happy that he took to this immediately. Keep an eye out. I heard one of my dogs hacking and coughing from the other room, but by the time I heard it and got to the room, it wasn’t clear what he was choking on. I had three of these bones in the room at the time, but there was also food and such around so hard to tell. Recommend supervising your dog with the toy in the beginning at least.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 28, 2024
K
Verified Purchase
Kimberly Schiller
Charlottesville, US
★★★★★ 5
Lasts with a pitbull
Style: Black chew toys for dogs
Good for very aggressive chewers. Even large, strong jawed dogs. My 70lb pitbull loves them and they usually last 6 months before we have to replace (because she's chewed slowly down the ends) Would recomment!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 28, 2026

recommand products