Air gap for a 37k

[Larry Pruitt]

Does anybody have a close up pic of an air gap manifold for the fresh water tank?
If not maybe directions on how to build one. Also, can someone tell me how to get to the top of the tank

[Robbbyr]

Originally Posted by Larry Pruitt

Does anybody have a close up pic of an air gap manifold for the fresh water tank?
If not maybe directions on how to build one. Also, can someone tell me how to get to the top of the tank

Here's mine, constructed from 1" PVC fittings from my local Lowes. The barbed elbows are from Amazon. There also were a couple of 1" street elbows. Disregard the hot water recirculation return connection, that is where my recirc system drain back to the freshwater tank.

Elbows: https://www.lowes.com/pd/LASCO-1-in-...Fl0swMzpHMWK5k

Barbed elbows: https://www.amazon.com/gp/product/B0...o4kochYRHvCA4Q

[Robbbyr]

Originally Posted by Larry Pruitt

Does anybody have a close up pic of an air gap manifold for the fresh water tank?
If not maybe directions on how to build one. Also, can someone tell me how to get to the top of the tank

To get to that area in my 2014 TS I just had to remove the carpeted panel (4 screws) in the passenger side compartment opposite my generator.

[Larry Pruitt]

Thank you so much
That’s exactly what I was looking for

[Robbbyr]

Originally Posted by Larry Pruitt

Thank you so much
That’s exactly what I was looking for

You are welcome.

It is hard to see from my picture's angle, but the manifold is installed "tipped" so the side connected to the tank fittings (and my recirc connection) is lower than the side where the vent/overflow lines connect. That allows the hot water returning to tank to just drain back into tank. And it provides the "gap" necessary to stop the siphoning effect.

[Rustynuts]

If your K model has the water tank above the propane tank, remove the carpeted panel above the propane tank, that is where it is on my RB and had very little room above to work with. I used piece of wire to work the vent lines up across the top of the tank to the passenger side and then built the manifold as you can see in the pics below. I did have to extend the lines about 6” to connect to the manifold. I used 3/4” pvc to build and extend it to the back of the compartment. Since building this, I haven’t experienced any water loss.

[Larry Pruitt]

I need to look at my K this afternoon but I believe my fresh tank is behind my propane tank

[Larry Pruitt]

I know I’m being a pain but here goes, my fresh tank is above my propane tank. The nautilus system is on the left hand side, but the overflow tubes are in the center. I removed the carpeted panel but there is no way to get to the top of tank from on top or from the bottom. Is there a way to get the tank out to get to overflow tubes to install an air gap? Do i have to remove the incoming cold line to the water pump in order to move the tank out to get to the overflow tubes?

[Larry Pruitt]

I could do an air gap like Rustynuts did, but i would like to install a recirculating line into the tank also

[Jmorenz]

Originally Posted by Larry Pruitt

I know I’m being a pain but here goes, my fresh tank is above my propane tank. The nautilus system is on the left hand side, but the overflow tubes are in the center. I removed the carpeted panel but there is no way to get to the top of tank from on top or from the bottom. Is there a way to get the tank out to get to overflow tubes to install an air gap? Do i have to remove the incoming cold line to the water pump in order to move the tank out to get to the overflow tubes?

I have a 2022 37K as well, I can’t find an easy way for this either.

[Rustynuts]

My RB is the same as the K with the water tank above the propane tank. My vent lines were more in the left front corner of the top of the tanks. What I did was have my son start pushing up on the vent hose from underneath, one hose at a time, while I used a long wire with a hook on the end, from the passenger side and hook the hose and fish it across the top of the tank. I had about 2” of space above my tank and the lines were a little short but I was able to get in there and using a heat gun to soften the lines, get a barbed fitting pressed in and a hose clamp on them. Mine were a vinyl hose but I think I have seen newer units have PEX line for the vent lines so that would make it a little harder. If yours are pex, then you would probably need to remove the Nautilus panel to access which installed that hard as each line just screws onto the back of the panel, I have had mine off several time. Hard to say without seeing pics. As far as a hot water return line for a circulation system, both Robert and I used one of the vent lines for this, it works great. In this pic, you can see the 3 vent lines in the top corner of the tank with the panel removed.

[Jmorenz]

Originally Posted by Rustynuts

My RB is the same as the K with the water tank above the propane tank. My vent lines were more in the left front corner of the top of the tanks. What I did was have my son start pushing up on the vent hose from underneath, one hose at a time, while I used a long wire with a hook on the end, from the passenger side and hook the hose and fish it across the top of the tank. I had about 2” of space above my tank and the lines were a little short but I was able to get in there and using a heat gun to soften the lines, get a barbed fitting pressed in and a hose clamp on them. Mine were a vinyl hose but I think I have seen newer units have PEX line for the vent lines so that would make it a little harder. If yours are pex, then you would probably need to remove the Nautilus panel to access which installed that hard as each line just screws onto the back of the panel, I have had mine off several time. Hard to say without seeing pics. As far as a hot water return line for a circulation system, both Robert and I used one of the vent lines for this, it works great. In this pic, you can see the 3 vent lines in the top corner of the tank with the panel removed.

I think your correct Brian, when I was investigating this in the spring, I figured the Nautilus needed to come on to get to the top of the water tank. I needed to do other things so I have put it off.

[Jmorenz]

Originally Posted by Larry Pruitt

I could do an air gap like Rustynuts did, but i would like to install a recirculating line into the tank also

Did you solve this? remove nautilus?

[rmarkarian]

Does anyone know why there are 3 drains for the freshwater tank? I am thinking of connecting a recirculation line to one of them, but do not want to impact the drains capability. I have 2021 37K and think running hot water circ system from the kitchen faucet area. Any advice regarding that?

[Robbbyr]

Originally Posted by rmarkarian

Does anyone know why there are 3 drains for the freshwater tank? I am thinking of connecting a recirculation line to one of them, but do not want to impact the drains capability. I have 2021 37K and think running hot water circ system from the kitchen faucet area. Any advice regarding that?

I was told by Jayco Service that it is to ensure sufficient overflow capacity when hooked to City water to prevent overpressurization when tank full. I was there for warranty work where they braced across my frame rails under my freshwater tank to prevent it from sagging.

My recirculation return line goes into my air gap manifold directly so the return water can either run right back into the tank or overflow if tank already full.

[rmarkarian]

So I took a look at my setup on the 2021 37K. Fresh tank is above the propane, but its footprint is a bit bigger. As you can see in the pic I only have 1.5 to 2 inches to work in. Drains are on top of tank 48" away from the edge. I think that can work since there are 3 1/2" drains which is equal to (.25*.25*3.15) x 3 = .590625 of area in the pipes and I could use 1" = (.5*.5*3.15) = .7875 of area. Formula is Pie*r2. I might be able to tap the adjacent hot water line with the solenoid and run it back to tank thru air gap. Anybody have ideas if my math would be correct?

[rmarkarian]

Brian, when you fished the 3 overflow tubes across the top of your water tank did the 90-degree elbows turn so they were facing the passenger side.? I am thinking of extending the lines by a few feet from below before I pull them over, as I can reach them from under the chassis. I am concerned that I may break the elbow when fishing it across the tank. Yours appear to be facing the passenger side across the tank and I am wondering if you had to remove the Natilus to get a wrench on the elbows or if they just unscrewed 180 degrees as you pulled overflow lines to the passenger side. Bob

[Rustynuts]

Originally Posted by rmarkarian

Brian, when you fished the 3 overflow tubes across the top of your water tank did the 90-degree elbows turn so they were facing the passenger side.? I am thinking of extending the lines by a few feet from below before I pull them over, as I can reach them from under the chassis. I am concerned that I may break the elbow when fishing it across the tank. Yours appear to be facing the passenger side across the tank and I am wondering if you had to remove the Natilus to get a wrench on the elbows or if they just unscrewed 180 degrees as you pulled overflow lines to the passenger side. Bob

Mine were pointing towards the front left of the tank. I used a the wire with a U-bend on the end once I has the lines pulled over toward the passenger side. By hooking the U-bend around the hose right at the fitting, they easily swiveled around toward the passenger side as I gently pulled on the hose. After I got them across, I realized I had to lengthen them, so adding some length to the hoses before fishing them across is a good idea. I would probably try swiveling them around first and if they dont easily move, then tear into the Nautilus panel. It probably all depends on who installed the fittings that day and how tight they put them in.

[rmarkarian]

Thanks to Brian and Rob R design ideas, I was able to complete the Air Gap on my 2021 37K this weekend. As you can see from prior pictures I had only 1 1/2" of space to work in. I used 3/4" Sch 40 pipe as well as a condensation line to get around a mounting bracket that was in the way. After extending the overflow lines from underneath the RV I was able to pull two completely around and connect to the T's of the air gap. The 3rd line was used to connect to the water heat circulation solenoid for direct tank return. The hardest part was installing the Solenoid into the PEX line next to the tank. I used a sharkbite T with female NPT threads and went directly to solenoid, and mounted the whole unit on 1" wood so no stress on the PEX line. I mounted the entire unit in a way that would not stress the PEX when the coach was driving.