I have finally completed my customized Fresh Water Tank Auto-Fill Project.
I must say that it was a challenging exercise to plan out this project because I wanted it to operate a specific way. However, it was fun to put it all together plus it works exactly as I had planned.
Now that it is finished, there will be no more sitting around waiting for the tank to fill when hooked to shore water. No more watching the level to make sure I don’t overfill the tank. No more cleanups in the service bay from the gallons of fresh water flowing out the gravity fill tube flooding my bay AND soaking my new roll of paper towels that I had just hug there in the dispenser. No more mud all around the RV from gallons of water flowing out the overflow onto the ground. AND, finally, no more worrying about filling the water tank while multi-tasking.
Following is the list of parts that I had purchased for the project along with an explanation of how it all goes together.
1.) 1 - Water Tank Float Switch – Look for one that is self-sealing. I chose one distributed by Devils Own Racing purchased on eBay. Due to the thickness of the water tank, the silicone seal that came with the switch was not long enough to create a good seal. I purchased a black rubber stopper and drilled a small hole just large enough to slip the wires through including the small end and epoxy it together. I also had to epoxy a stainless steel fender washer on the outside end of the rubber stopper to act as a stop so it wouldn’t get pushed all the way into the tank by mistake. I installed the float switch in the Normally Open position with the float hanging down. Once the water tank is full, the float rises and the switch closes.
Self Sealing Float Switch
2.) 1 - Water Fill Solenoid Valve– 12 VDC Normally Closed – 3/8 inch NPT – Purchased from eBay. The eBay seller I chose has both 3/8 and ½ inch. I chose the 3/8 as that was the size of the PEX tubing that I cut into for a water supply (Washing machine supply line) although once I got into the project further, I had to purchase some 3/8 to ½ adapters so the ½ inch solenoid would have been the better choice. I bought mine from this eBay seller -
CORE CHUCK, RIGHT HAND items in PRECISION LINK store on eBay!
3.) 1 – ½ inch Vanguard Apollo Compression PEX T. This is for the Fresh Water Tank input line. I spliced into the water fill line that comes directly from the 3-way manual fill valve to the tank. It was an easy line to completely remove from the 3-way valve end and the tank end as both ends had the twist off fittings. The manual fill line still remains factory so I haven’t given up the ability to fill the tank manually. However, after using the Auto-Fill I can’t see myself EVER using the manual fill valve again.
4.) 1 – ½ inch NPT Female threaded PVC T.
5.) 2 – ½ inch NPT threaded PVC Street EL’s.
6.) 2 – 3/8 to ½ inch NPT Vanguard Apollo Compression PEX Fittings.
7.) 1 - 10 foot section of ½ inch PVC pipe and two slip to ½ inch NPT fittings. This PVC pipe goes from one side of the coach to the other side adjacent to the fresh water tank.
8.) 3- Flex water lines of various lengths for connecting to and from the PVC pipe fittings, etc. One goes from the one end of the PVC pipe to the ½ inch T. One goes from the other end of the PVC pipe to the output side of the Solenoid valve. One goes from the input side of the Solenoid valve to the PVC T that is in the water supply line.
Line items #3 - #8 are all available from any big box store or hardware such as Home Depot or Lowe’s.
9.) 1 - Intellitec Water Pump Latching Controller – I purchased a used one from VisoneRV Salvage Yard.
Used RV Parts And Accessories | Visone RV Monaco Parts Dealer | rvparts.visonerv.com
10.) 1 - 5 Pin 12 VDC Relay and Socket – I bought a pair from Amazon.com that came with two relays, two in-line fuses, and two sockets. You only need one for this project.
11.) 2 - Dual Gang Bezels in plain black with two Dual Momentary Switches and Two Large Red Indicator Lamps – I chose to mount one in the Service Bay and one mounted near the bathroom vanity. I purchased these from Northwest RV Supply in Eugene Oregon.
12.) Two Green 12 VDC LED’s from Radio Shack that I added to the bezels.
13.) Various Wire and Connectors.
I chose the 3/8 PEX washing machine water line for the water supply as it was the easiest to work on being at the top of the Manobloc. I cut the PEX and installed the PVC T and other fittings to form the complete T which goes from the 3/8 PEX to the ½ inch PVC T. There is a small nipple placed into the center of the T which a 30 inch flex hose with ½ inch ends is attached to the nipple. This hose goes through the wall opening where the other PEX piping goes through over to the tank bay and connects to the input side of the 12 VDC water solenoid. There is another flex hose from the output side of the water solenoid to the curbside end of the ½ PVC pipe. And the last flex hose from the roadside end of the ½ inch PVC pipe to the ½ inch T which has been installed into the water tank fill line.
Now, when I need to fill the water tank, I simply press one of the Auto-Fill momentary switches which then energizes the system. The Green LED will light up noting that the system is energized. The water fill solenoid valve will open allowing water to flow into the tank. When the tank is full, the float switch will close which then activates the 12 VDC relay coil. This specific relay action closes the internal switch inside the relay which then cuts power to the water fill solenoid. This same action will also light up the large bright RED indicator light at each one of the control switch locations both inside the coach and in the service bay. The RED light will alert you that the tank is full. You can then de-energize the system by touching one of the momentary control switches which then turns OFF the system.
If you happen to leave the control switch on and then use water from the tank, the system would short cycle on and off frequently attempting to keep the tank full. So I highly recommend that once the tank is full, you turn off the system. Once the tank gets low enough to refill you can activate the switch once again.
In addition, if you happen to have the water pump on when you energize the Fresh Water Tank Auto-Fill System, your pump will run continuously flat out on high so I recommend that when filling the tank, you turn off the water pump. Sometimes depending on my location I will supplement the shore water pressure by having my water pump on too.
Now if the project I described above is too complicated for you BUT you still would like some sort of warning when the fresh water tank is approaching the full level, just purchase the same Float Switch above along with a 12 VDC siren or loud horn. Wire the horn/siren in line with a rocker type On/Off switch and install the float switch in series with the horn and a 12 VDC positive wire. Then run the other wire to ground. Now when you decide to fill the fresh water tank with the manual fill valve, turn on the rocker switch too. Once the water tank is full, the horn/siren will sound off alerting you that the tank is full so you can go turn of the water AND the horn/siren. Well that’s unless you forgot you were filling the tank and left to go shopping or something else. Now your neighbor’s are totally pissed off at you for the severe noise pollution you have caused plus all the water that is flowing from your overflow tube. LOL
Here are a few photos of my installation. I also have drawings and electrical schematics of the project.
Dr4Film ----- Richard
Linear Mode
