My Nautilus Replacement Project

[MnMRV]

Hey everyone, I am following the foot steps of those who have replaced their Nautilus panel. Big thanks to bogen2 for his post and those of you who commented in that thread. I will try to post my pictures after I am done.

I am almost there, with one small question: is there any reason to add a check valve immediately behind my city water connection? My replacement has an on/off valve, so no concerns about pumping water out of the city water connection. (Don't worry, my black tank connection has a check valve!)

[TedS]

One advantage to no check valve while connected to city water, heated water has some place to go and the expanding water will not overpressure your system as long as the on/off valve is 'on' , open.

[howson]

Hey everyone, I am following the foot steps of those who have replaced their Nautilus panel. Big thanks to bogen2 for his post and those of you who commented in that thread. I will try to post my pictures after I am done.

I am almost there, with one small question: is there any reason to add a check valve immediately behind my city water connection? My replacement has an on/off valve, so no concerns about pumping water out of the city water connection. (Don't worry, my black tank connection has a check valve!)

When using the pump (and water from the fresh water tank), without that check valve the pump will shoot water out the city water inlet.

Look carefully at the diagram below. (For more info on all the configurations see https://gdrvowners.com/forum/operati...el-information )

The yellow diamond is a "check valve". Normally water stops here as it can't flow against that valve (thus why the diagram does not show water flowing in that direction when on the pump). Remove that check valve and you can see how the water will travel.



Ironically, your black water connection should not have a check valve on the inlet. The only valve should be the "atmospheric" valve as originally configured. When the hose is disconnected from the black flush line it is normal (and expected--desired!) to have fresh water flow back out the inlet.



Howard

[TedS]

howson, only if the pump pressure is higher than city water pressure. Note in the description he has installed an on/off valve in place of the check valve. Just need to remember to turn the valve 'off' when using the pump without city water connected.

[bogen2]

One of the advantages of the manifold valve design is it eliminates the need for a check valve in the city inlet connection as well as the water heater.

Bob

[MnMRV]

Ironically, your black water connection should not have a check valve on the inlet. The only valve should be the "atmospheric" valve as originally configured. When the hose is disconnected from the black flush line it is normal (and expected--desired!) to have fresh water flow back out the inlet.



Howard

I'm confused. It is my understanding that a check valve is required so that there is no chance of anything flowing from the black tank into the fresh water supply.

Is this showing that there is one further up the line (i.e., not at the panel and I would know if I messed with it)? This is because, if it were at the inlet, water would get trapped in the hose to the black tank?

[TedS]

The installed vacuum breaker/check valve allows water to drain both to the black tank and to the water inlet on the panel thereby breaking possible siphoning of black tank water back to the panel inlet. There is no check valve in the panel water inlet. That lack of check valve allows water to run out, draining the line.

[Country Campers]

I'm confused. It is my understanding that a check valve is required so that there is no chance of anything flowing from the black tank into the fresh water supply.

Is this showing that there is one further up the line (i.e., not at the panel and I would know if I messed with it)? This is because, if it were at the inlet, water would get trapped in the hose to the black tank?

There is a built in check valve on the tank side of the atmospheric breaker that does not allow any of the black tank stuff to return to the fresh water hook up on the panel. Other than that it operates as TedS descirbes above.

Brian

[howson]

bogen2 and TedS

Thanks for the inputs and clarification about how the modified panel works -- I learned something! (That's always good.) Makes me wish I'd done the full-fledged upgrade when I rebuilt my Nautilus panel.

Howard

[MnMRV]

Cool, add the check valve to my large pile of stuff to return to Lowe's.

I guess I should go ahead and share my other planned changes to make sure I am not making any other mistakes: (1) replacing the fitting for the black tank - turns out this only involves the 1/2 barb to garden hose; (2) using a hose connection with a valve and omitting the ball valve above the city water in; (3) I used the linked manifold to connect the panel, pump out, water heater in, and cold water to inside.

Then, here is my new, half-baked idea: I was thinking about putting small acrylic sheet "splash guards" around the top and left side of the city water hose connection to keep any loose hose connections from spraying everywhere in the wet bay. Anyone done that or something similar before?

[MnMRV]

I got everything hooked up. Well, all the plumbing anyway.

I didn't take good enough photos or notes to remember which wire goes where on the pump switch and don't feel like going out there with the voltmeter at this point. I will take it for today.

[howson]

I got everything hooked up. Well, all the plumbing anyway.

I didn't take good enough photos or notes to remember which wire goes where on the pump switch and don't feel like going out there with the voltmeter at this point. I will take it for today.

If your setup is like the one on my 315RLTS it's a three-way switch (pump can be turned on from the Convenience Panel, too) so take care hooking it back up. If I remember right GD used a white wire (typically -12vDC return) as the alternate hot input(!). Thankfully I caught it before having to chase down a blown fuse.

[Country Campers]

MnMRV

Here is a picture of my wiring, you may need to zoom in to see the wire colours.

Hope this helps you.

Brian

[TedS]

This from B&B repair manual. Sort of clear.

[MnMRV]

Thanks! I actually had a photo, I just couldn't decide if the spot labeled "1" on the switch was at the top or bottom. I thought about it more this morning and realized as long as I knew the middle position, I was good. My photo showed me that. So, pump is up and running! No leaks!!

The water pressure seems a bit low from the pump, even after letting the faucet run for ~10 minutes. It continues sputtering with air bubbles. I will investigate more later.