DIY RV Water Filter System For less than $100

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For years I have used the disposable RV inline water filters as I filled my fresh water tank or when hooked up to city water at a campground. I started this one summer after we got the travel trailer out of storage and I had sanitized and flushed the tank, but the water had a bad taste and odor. I thought it could be from the well water, but our well had great tasting water. I had sanitized and flushed the system but still I couldn’t get rid of the bad taste. I decided to filter all the water going into the system to see if that fixed the problem. It helped but didn’t eliminate it completely.   Baking soda flushed through the system finally got rid of the odor and bad taste, but I continued to use the inline filters as prevention. Two years ago we upgraded from our 26’ Travel Trailer to a 43’ Heartland Cyclone 5th wheel toy hauling beast.

I figured the inline filters was good enough before so I continued to use them. Only now we were living full time in our Luxury RV. I read a few articles about water filters that concerned me. I discovered that the filter I was trusting to protect our RV and provide safe drinking water, regardless of the source, was not up to the task. After much research with help from Mr. Googlepants and the great resources on the Heartland Owners Forum, I decided on a two-stage whole coach system.

This led to more questions. Where to put these house sized filter canisters? Inside or outside? Fixed position or mobile? DIY or ready made system. There are all kinds of options out there and some great ideas. I really like one I saw that was mounted in a tote, big enough to accommodate all my hoses and other water associated accessories. This idea could make set up, fairly easy. Another great idea that I considered was to mount them on one of the pass through storage panels that could be hinged into a door, for easy access.

Then we had a deep freeze where we were set up in Kansas. Our heated hose didn’t freeze but the inline water filter split open like a banana. Fortunately nothing else was damaged. So that settled the where question for our new water filter system. I decided on using a hinged panel on the divider wall of our pass through storage. This location stays warm from the ambient heat coming off the furnace and will keep the water filters from freezing. I also decided to include our water pressure regulator on the outlet side of the filters to eliminate one more step in our setup process. I have read pros and cons to putting the pressure regulator after the filter instead of on the input side of the system.   However the canisters I chose have a 125 psi rating and I also include a pressure gage on the input side so I can check the pressure coming from the source. So far, I haven’t seen anything over 100 psi. This system set up the way I have it, keeps all the water hook-up components in the heated compartment, except the hose. We use a Pirit 25” heated hose whenever there is a chance of freezing temperatures.

As I began measuring for the Water filters I discovered I would need to adjust the spacing of the frame on the divider wall to accommodate the hinged panel and filter system. I also realized if I moved a few other components (water pump and transfer switch) in the utility area, behind the wall, I could move the wall and gain 3 ½ feet of extra floor space in the storage area; BONUS!!! Moving the wall and cutting the original divider panel into two panels required only one 2”x2”x8’ for framing and a set of door hinges. I had the use of my son-in-laws cordless skill saw, so that made the task easier and only took about 2 hours.

Putting the components for the water filter together took about 20 minutes. It was the multiple trips to the hardware store and home improvement stores for the right stuff that was, by-far, the greatest time killer. Even though I thought I had a great plan (See PDF) there were some unforeseen challenges that required additional trips. Of course I complicated the mater by also upgrading our water valve system at the same time.

Our coach came with the Anderson Valve 200RV, which is a slick, one valve, system. It allows you to direct the water from a city faucet to your tank, or to the fixtures, when you are connected. You can also select to use the fresh water tank when not connected. The fourth feature allows you to sanitize the fixtures in your coach from a non-pressurized source (bucket), using the onboard pump. I upgraded to the Anderson 200RV-WHBSD. In addition to all the features listed above it also allows you to bypass and drain the hot water heater, and sanitize the fresh water tank from an unpressurized source using the pump. This last feature was why I decided on this Water Valve set up. I can now use the onboard pump to fill the fresh water tank from our AquaTank2 150 gallon fabric bladder, that we transport fresh water in while we are boondocking.

So far we are very happy with the set up and it really simplifies our hook up procedures when we are at an RV park or location with water hookups. You can checkout the youtube video about this project HERE. Below are the step-by-step instructions for the water filter setup, and the parts you will need. To get a free PDF with the diagram and parts leave a comment and I will email it to you. If you have any questions about this project, other RV maintenance, or your RV Adventures please leave a comment below.  Remember, we are not Snow Birds we are FreeBirds!

The First part of this project is to assemble the 2 water filter housings and connect them together, add the fittings for a pressure gage at the inlet and install a pressure regulator to the outlet.

I am using the OmniFilter OB1 Canister Filter for ¾” fittings because the have a built in mounting bracket on the head and a pressure relief valve on each canister. You could use any of the whole house filter canisters for 10-inch filters, but they may require additional parts for mounting. The OmniFilters are relatively inexpensive at less than $20 each on Amazon. I use a string type five-micron sediment filter in the first housing and a less than one-micron carbon block filter in the second housing to remove chemicals and bad taste.  You can find the Canisters, Filters and all the parts I used in the Water/Waste Water Menu, under the Water Filter Project tab, just add all the items to you cart and a checkout you are routed to Amazon for purchase.

To start I applied Teflon tape to all the male threads except the hose side of the ¾” MIP X Male Hose Hex Nipple that connects to the Pressure Regulator, the two ½” MIP Hex nipples that connect from the water panel check valve to the input, and from the output to the Fill Valve. These connections are to hoses that have washers and don’t need thread sealant.

  1. Connect the two filter canister heads with the ¾ X 2” Hex Nipple. Make sure the flow arrows are facing the same direction.
  2. Connect the ¾ MIP X ½ MIP Hex Nipple to the input side of the Canister Heads.
  3. Connect the ½ Tee to the input side ½ MIP Hex Nipple.
  4. Thread in the ½ MIP X ¼ FIP Bushing in to the top of the Tee fitting.
  5. Attach the Pressure Gage.
  6. Thread in and tighten the ½ MIP Hex Nipple to the Input side of the Tee Fitting.
  7. Thread in and tighten the ¾ MIP X ½ Male Hose Hex Nipple to the output side of the Canister assembly.
  8. Replace the ½ MIP to ¾ Male Hose in the Pressure Regulator with the ½ MIP Hex Nipple.
  9. Attach and tighten the Pressure Regulator.
  10. Use the Screws included to hang your assembly in your desired location, connect the hoses, turn on the water and you’re done. The OmniFilter instruction do recommend you run the water through the system for 5 minutes to flush it before you use it.

5 Responses

    • Les

      I can’t find this on your site?
      “Water/Waste Water Menu, under the Water Filter Project tab, just add all the items to you cart and a checkout you are routed to Amazon for purchase.”


  1. Oso

    I am going to convert a box truck into a camper/tiny house and i will be doing everything myself. Would you please send me the pdf

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