Water Gauge Replacement (Hill Method)

(Note: This is one of several methods of installing the Topargee water gauge in the Revel. See here and here and here for others.)

Topargee Water Gauge Install and Plumbing Cleanup

The remaining water in the fresh tank as reported by the One Place is useless to me.  When there is 71% of capacity remaining, it reports 1/3 remaining. When there is 10% remaining, it reports empty.  During the range of 71% to 10% you have no idea where you are in that range. That is not very useful because that is the time when I really want to know how much water I have.

With input from Jeff and Jim I decided to install a Topargee “water tank gauge” with a flush mount display https://aquaviewinc.com/product/h2f-fm/. The Topargee is not really a water tank gauge. It measures the flow of water leaving the tank. It is surprisingly accurate and much more useful than the One Place.  I chose the option with the flush mount display rather than the BlueTooth version because I thought the display would likely last longer than the company will be able to keep the iOS app updated. (Thanks to Jeff for this pro tip). There are two cons to this gauge that I know of: you have to remember to reset it when filling the water tank, and there is no easy way to tell it that you just added 5 gallons of water.

I installed the display in the front of the galley cabinet (again, as suggested by Jeff and illustrated to me in pictures by Jim). This is not the best as the display is much easier to read from below than above. I did not see any easy way to run the wires somewhere else with a better viewing angle, so this is where it is.

The instructions say to mount the flow sensor in the middle of a straight run of pipe 400mm (about 16”) long. To get a straight run of pipe and to clean up the mess of fittings in the footwell area, I decided to reorganize all the plumbing. Fortunately, this mostly meant removing things. I eliminated everything I do not need:

• the water dump valve and its connections to the output from the pump,
• the antifreeze intake hose port and valve, 
• the spray port and 
• the hose fill port. 

What remains in the foot well are:

• gravity fill,
• from tank to pump,
• from pump to the rest of water system,
• from water heater to sink.

I added an air hose connection and selector valve for blowing out the system with air for winterization.

This simplifies things a lot (I have a big pile of little pieces of PEX and PEX fittings that I removed) and greatly reduces the risk of freeze damage. The air hose connection is made almost entirely of parts that were removed. The only part I had to buy was a 1/2” male to 1/4” female adapter. I used an air hose connector with 1/4” male thread that I had in my box of air hose parts.

The key to getting the run of straight pipe for the flow sensor is to modify how water gets from the pump to the sink and the rest of the system. Originally, the flex pipe from the pump went to a tee that sent water up to the sink or down to everything else. I changed this by replacing the tee with an elbow so the water went up. I then put the flow sensor in the middle of the vertical pipe and added a tee near the sink to send the water back down to everything else. This was a pretty simple plumbing change.

I wanted to preserve the flexible white hoses on either side of the pump as these are supposed to help reduce noise from the pump. Ideally, they should not touch anything as they get shaken a lot when the pump is pumping.

The only challenges I had with this job were:

• Finding fittings to adapt the BSP fittings on the Topargee sensor to PEX. In the end I gave up trying to find a suitable BSP connector (after buying two different ones, one of which I tried to modify) and went simple with a 1/2” female NPT to PEX connector from Home Depot: https://www.homedepot.com/p/Apollo-1-2-in-Brass-PEX-Barb-x-1-2-in-Female-Pipe-Thread-Adapter-APXFA1212/301541029  NPT threads are not supposed to seal to BSP threads, but with 4 turns of teflon tape and a little pipe dope, and then thoroughly tightening, it seals just fine. The pipe dope probably is not needed. I think this is the way to go for most people. But Gus at Aqua View says that if you can get a nylon fitting, which he says are easy to get at RV parts places, it might work better than brass. The important thing is to not get a swivel fitting, which is what I tried at first. Swivel fittings seal with a washer so they should seal to BSP, but they have a central part holding the washer. This part would normally fit inside the pipe screwed into the fitting. The Topargee water flow sensor has a narrower internal diameter than pipe and this part will not fit inside the sensor. This is why Jeff and Jim had to modify their swivel fittings and sensors.
• Taking apart the existing PEX can be a challenge. If you do not need to connect to existing pipe, you can simply cut it and toss it. But sometimes you need to keep something that is there or want to reuse something. With a little practice it is easy to take the crimp rings off with a pair of diagonal cutters. I got pretty fast at this. The trick is to lift up the end of the ring that is exposed, by squeezing between it and the little tab the sticks up with your diagonal cutters. Then you can grab the end and peel it up. Once the ring is loose the PEX is not easy to pull off because it is distorted by the ring and retains this distorted shape. Gentle heating with a heat gun causes the PEX to return to its original shape allowing it to be pulled apart easily. Just heat until the indentations left by the ring start to smooth out a bit. I reused both the PEX and some fittings. I do not know if reuse is recommended, but where you connect to the existing plumbing there may be no choice. When I have a choice, I use new parts.

I had no experience with PEX and no PEX tools so I used PEXLock connectors. No special tools are needed-just big pliers. I found them easy to use and they can be removed and reused (I needed this!). If you only plan to do a little work with PEX this may be a better approach than getting a special crimping tool. https://flairit.com/product-category/pexlock-fittings/ 

Finally, because I no longer need the “city fill” on the drivers side (I only used it for blowing out the system with air) I drained it and capped the connections. This required a 1/2” NPT cap and 1/2” NPT plug from my local hardware store. This was easy. Now there is no risk of the water in this line freezing where it penetrates the exterior of the van.

I wired the Topargee in parallel with the water pump so that it gets power when the pump gets power.


The water display for the Topargee between the electrical outlet and the switches for the pump and macerator.

The footwell area under the galley cabinet after I was finished. Not much here. The valve used to select input from anti-freeze instead of the tank was reused to select between the tank and the air hose fitting as the source for the water system. The valve and air hose fitting are inside and covered normally. I want them to be safe from freezing in severe weather.

Close up of what is left in the footwell with an air hose connected and the valve set to air as the source. I am blowing out the system.

Inside the galley cabinet.

Looking into the footwell from where the refrigerator goes. Compared to before, there is hardly anything here.

I made a temporary cover out of some closed-cell foam. This should work until I come up with a plan for a permanent cover.

White cap (seals with teflon tape applied to threads on the tee) and plug (seals with existing washer) on a threaded tee and elbow to disconnect the city fill port and eliminate the risk of the port freezing. This is beside the thermostatic mixing valve under the bench.