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  1. RV Water Inlets
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  3. City Water Inlet
  4. Dual Water Inlet
  5. Gravity Fill Inlet
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B&B RV Water Center - City Water and Gravity Fill - Brass Check Valve - Key Lock - Black
B and B Molders

B&B RV Water Center - City Water and Gravity Fill - Brass Check Valve - Key Lock - Black

Part Number: BM78MR
$64.24
RV Water Inlets
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Update your RV's fresh-water access with this dual-fill secure hatch. Includes a gravity port to fill your fresh-water tank and a threaded brass check valve for pressurized city water. Vent allows air into your tank so water flows smoothly. Great Prices for the best rv water inlets from B and B Molders. B&B RV Water Center - City Water and Gravity Fill - Brass Check Valve - Key Lock - Black part number BM78MR can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (63)
  • Q & A (0)
  • Videos (1)
  • Photos

B and B Molders RV Water Inlets - BM78MR

  • City Water Inlet
  • Dual Water Inlet
  • Gravity Fill Inlet
  • Black
  • Flush Mount
  • 7-5/8W x 6-1/2T Inch Flange
  • Brass
  • B and B Molders
  • Plastic
  • 3-1/4 Inch Deep
  • 5-7/8W x 4-3/4T Inch Cutout

Update your RV's fresh-water access with this dual-fill secure hatch. Includes a gravity port to fill your fresh-water tank and a threaded brass check valve for pressurized city water. Vent allows air into your tank so water flows smoothly.


Features:

  • Dual water hatch provides a gravity fill port and a city water inlet on your RV
  • Gravity fill opening and spout lets you fill your fresh-water tank
    • Uses barbed connection inside for 1-3/8" or 1-1/4" hose to tank
    • Twist-on cap holds fast to keep fill clean and prevent loss
  • City water inlet connects to a drinking water hose for a pressurized connection at home or at park
    • Brass check valve keeps pressurized water from backflowing
    • 1/2" MPT fitting inside connects to RV system
    • Rubber plug fits tight
  • Air vent attaches 3/8" tubing (not included) to tank, balances air pressure for smooth water flow
  • NSF IAPMO, and CSA certified
  • Includes mounting hardware, lock, and key
  • Made in the USA


Specs:

  • Cutout dimensions: 4-3/4" tall x 5-7/8" wide
  • Outside dimensions: 6-1/2" tall x 7-5/8" wide
  • Collar depth: 1-1/2"
  • Total depth: 3-1/4"
  • 1-Year warranty


723-037-00074 B and B Molders City/Gravity Water Center w/ Brass Check Valve, Key Lock, Black - 94255





Video of B&B RV Water Center - City Water and Gravity Fill - Brass Check Valve - Key Lock - Black
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Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Complete Breakdown of the B and B RV Water Center

Hello neighbors, Steven here with etrailer.com. Today we're looking at our B&B RV Water Center and you can connect city water or gravity fill it with the built-in brass check valve, lock and key and it's black in color. So folks, a dual water hatch is gonna provide a gravity fill port and a city water inlet to your RV and let you fill your fresh water tank. So you got the city hookup here with the brass check valve included with the strainer to keep everything clean. It's got a rubber cover on it that you can take on or off. You got the fill cap here for the gravity fill.

You got an air vent down here. And one thing to point out on the door here is one, it's lockable, you can twist the key and lock it, but two, it's got a nice little pass through here built in. So when you hook up the hose, you can have the hose and have it locked still so no one can disconnect your water. So nice little feature there from the start. The whole thing here is made of a nice heavy duty plastic.

It has been UV treated, so it's not gonna discolor, it's not gonna fade over time and all that kind of stuff. It is NSF certified, TEI certified CSA and IAPMO certified as well. And like I said, you got twist on caps and rubber plugs to hold everything in place, you'd need a 3/8" hose to air vent this. That's gonna help balance the air pressure for smooth water. That's this guy here.

Again, the brass check valve here with the half inch MPT or male pipe threads, that's standard size. And on the the gravity fill here, you've got the barb fitting. That'll connect either to a 1-3/8" or a 1-1/4" hose. As far as installing, you've got all your screws here, they've been painted black on the head. I turned a couple around just so you can see that.

And you got your included butyl tape. Now butyl tape, if you're not aware, is basically a putty like substance and you just simply roll that out, put it around the whole edge, put it in place on the RV or camper, put your screws through it through the holes, and it's gonna make a nice pressed tight fitting. It's gonna kind of scooch that out if you will, and make everything nice, watertight and everything for you. Now as far as some dimensions, overall I get 7-5/8". If I go this way, I get 6-1/2". The depth here is 1-1/2". Now that's just on the part that's gonna be recessed behind there. Now as far as this way, I get 4-3/4" on that cutout by 5-7/8". Now the total depth, if you count the hose barb fitting this way, I was getting about 3-1/4", but I had to use another straight edge here to get it accurate so. Again folks, this is the nice B&B RV Water Center for the city water or gravity fill. Nice one year warrant on the products folks, I think you'll be happy with it. I'm Steven, thanks so much for watching and have a great day.

Customer Satisfaction Score:

Ratings & Reviews

4.7

63 reviews
5 Stars
(51)
4 Stars
(8)
3 Stars
(2)
2 Stars
(0)
1 Star
(2)
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by:
Looks to be a direct replacement for current unit. Good kit that comes with all parts needed to install. Excellent tracking on order and communication on short back-order delay. Thanks
by:
I'm not impressed without the to just replace the check valve only. For reasons of needing the trailer up and running ASAP, I bought the poor designed product. I will be modifying my old one to be able to repair easily and be a sustainable product, instead of the wasteful use that ends up in a landfill.
by:
Much better than the original that came on my trailer. It was an exact fit to the opening with even the screw holes aligning. And most importantly it has been 100% leak free with daily use over the past couple of weeks. It’s a solid replacement product.
by:
Exact replacement for my camplite travel trailer.
by:
perfect replacement for my Sundowner Toy Hauler!
by:
Works great
by:
by:
by:
by:
Excellent.
Perfect exact replacement,
But with a couple upgrades.
Simple install.
Took a little over 30 minutes.
Could not be happier.
Etrailer you rock. !
Will be back for all my trailer part needs.
Claire H. profile picture
Etrailer Expert

Claire H.

6/10/2026

Thank you for the kind words! We're happy to assist you with any of your trailer needs in the future :)

by:
I was disappointed with this one. Despite use of Teflon tape on the threaded connections the one that I received leaked like a sieve. I ordered another similar replacement from etrailer, B & B Moulders Model BM83RR which has brass instead of plastic threads.
by:
I ordered as a replacement part for my 1999 Jayco 5th wheel. Fit perfectly and very pleased with the results!
by:
so far so good, the valve was installed and has worked as expected, it was the most optioned and expensive available with 3 different valves/uses and a locking exterior door and has worked as advertised.
by:
Overall nice product. Minor grumbles include: only one key, the latch could be improved (it’s a bit tight latching) and lastly, they place a gooey sticker on the door promoting the ability to key alike. I peeled it off the pebble finish and it left a gooey mess. Ugh.


Etrailer- first rate. Five stars…..
by:
It looks perfect it was difficult to find as the product is referred to as several names. Connections box water box ect. This is what I was looking for and it arrived really fast. I wish the trailer company here had told me that I could simply replace the guts and not spend $275 for the entire unit thats on me but telling me 8 weeks from products ordered out of the states is BS. etrailer has been great it arrived within the week across the boarder with no issues.
Thanks
by:
Thank you for having the part we needed at a fair price and fast shipping, this was not a common part and had variances in different models, you had the exact one we needed. thanks again
by:
Exact replacement needed for my customers RV. Quality was great and came fast! It does not come with a lock and key like the one previously installed but was able to swap the doors from the old one. Also comes with a small amount of butyl tape.
by:
Have always been very helpful and products have been reliable.
by:
We appreciate etrailer having what we needed to fix a camper. we were working on. Look forward to doing more business with you in the future recommend etrailer to anyone that would need an RV part. Thank you.
by:
Exact fit for a hard to find part.
by:
Dwight isvinstalling it today a perfect match!
by:
I wish the manufacturer used metal hose connectors instead of plastic
by:
Recived the Item #BM58MR quickly, estimate was a Friday about a week. I recieved it three days after ordering. The description and measurements given matched exactly. Came with all items necessary to install. Installation took about thirty minutes (your mileage may vary) i work slowly. Quality of the materials that the part is made of appear of good to excellent quality. Overall it was fantastic to find your company carried the product, and it was made of good materials. I will be looking to etrailer for any rv parts i may need. Thanks for reading this review, your looking in the right place.
by:
HIGHLY RECOMEND ETRAILER, FAST AND GREAT SERVICE
by:
Fast Shipping. Thank You!
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See what our Experts say about this B and B Molders RV Water Inlets


Info for this part was:

Employee Steven C
Installed by:
Steven C
Employee Wilson B
Updated by:
Wilson B
Employee Amanda M
Edited by:
Amanda M
Employee Cody B
Written by:
Cody B

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