Nautilus system re-piping - hot water heater bypass?

[FirstAscent]

Hello everyone,

I've recently been looking into completely re-doing the Nautilus system (I specifically have the P4), I've searched and come across many great ideas many of you have already done. I'm wanting to do something similar in what I refer to as the "H" design where you have your 5 valves in an H pattern for the different functions.

One thing I haven't quite figured out yet is how to add the hot water heater bypass and wondering if anyone has any great ideas you may have already implemented.
I DO want the bypass the be selectable from my new main control panel and not have to reach back to adjust valves behind the panel next to the HW heater itself. From what I've seen so far mean an additional 3 valves. Which isn't a complete dealbreaker I would just rather find a different way to do it having the bypass easily selectable at any time without disassembling panels.

Thanks for any input !!

I've got all my material so far, new PEX-A and will be using ProPEX fittings and ball valves. just can't decide on how I want to integrate the bypass

[Cate&Rob]

Prior to the "Nautilus" system, Grand Design used a "Kantleak" system by Anderson Brass. It did not live up to its name which was why it was replaced . . . but, that is another story. The Kantleak system is a very clever design that was poorly executed due to the supplier reducing costs by changing many components from brass to plastic.

Part of this design is a single valve that bypasses the water heater and does not need the problematic check valve on the water heater output. There are four connections to this valve. Cold Supply. Heater In. Heater Out. Hot System Supply. In normal position, Cold Supply is connected Heater In and Heater Out is connected to Hot System Supply. In Bypass position, Cold Supply is connected Hot System Supply and Heater In is Connected to Heater Out. This bypasses the water heater and drains the lines to/from the heater by connecting them to each other.

I have not yet figured out how to do this with standard valves . . . but, the design concept is very clever.

Rob

[TedS]

Get the red handle valve used in the P1 panel for the water heater bypass.

You will need to install a check valve in the water heater outlet.

[FirstAscent]

Prior to the "Nautilus" system, Grand Design used a "Kantleak" system by Anderson Brass. It did not live up to its name which was why it was replaced . . . but, that is another story. The Kantleak system is a very clever design that was poorly executed due to the supplier reducing costs by changing many components from brass to plastic.

Part of this design is a single valve that bypasses the water heater and does not need the problematic check valve on the water heater output. There are four connections to this valve. Cold Supply. Heater In. Heater Out. Hot System Supply. In normal position, Cold Supply is connected Heater In and Heater Out is connected to Hot System Supply. In Bypass position, Cold Supply is connected Hot System Supply and Heater In is Connected to Heater Out. This bypasses the water heater and drains the lines to/from the heater by connecting them to each other.

I have not yet figured out how to do this with standard valves . . . but, the design concept is very clever.

Rob

Thanks Rob, I've started investigating down that path as well actually. The valve port type would be an X (or double L port). It's a 4-way valve essentially, all the magic happens with the X porting. I am considering this if I can find a good quality valve that isn't ginormous. I'm trying to find this type in a small form factor, if I can, it'd be perfect. I have a couple suppliers I work with that have options, but they are much larger than I really want (even though they are 1/2" I/D's.

[FirstAscent]

Get the red handle valve used in the P1 panel for the water heater bypass.

You will need to install a check valve in the water heater outlet.

The valve itself is a basic 3 way valve, L port style I believe. it's nothing special. But it's how they have all the rest of the piping routed (which is a mess) where they are doing a lot of the bypass. Isn't the check valve where a lot of people are having issues though? Which is part of the reason I'm trying to avoid that route.

But... maybe the answer is simply "buy a better check valve" haha

[Cate&Rob]

FirstAscent

You might want to consider obtaining a valve from Anderson Brass. Or even an entire "Kantleak" RV water control panel. I understand that Anderson has gone back to their previous all brass design which combines their innovative and relatively simple designs with quality parts made in the US. If they had not gone to plastic components a few years back, they would still have the majority of the RV business. A far simpler system to connect than Nautilus, with full functionality from only two valves.

The water heater outlet check valve required with the Nautilus system is a common failure point with that system.

Rob

[Canyonlight]

FirstAscent

You might want to consider obtaining a valve from Anderson Brass. Or even an entire "Kantleak" RV water control panel. I understand that Anderson has gone back to their previous all brass design which combines their innovative and relatively simple designs with quality parts made in the US. If they had not gone to plastic components a few years back, they would still have the majority of the RV business. A far simpler system to connect than Nautilus, with full functionality from only two valves.

The water heater outlet check valve required with the Nautilus system is a common failure point with that system.

Rob

A number of us having been communicating here and elsewhere about the new and highly improved "all brass" Kantleak panel by Anderson Brass. I may be doing this if we keep our 303 and have to replace our current panel. One owner has done this already but I do not recall who it was. Maybe it was John Jkwilson ?

Here is the link to the RV panel on Anderson Brass site: https://www.abcorv.com/

Dan

[Jkwilson]

A number of us having been communicating here and elsewhere about the new and highly improved "all brass" Kantleak panel by Anderson Brass. I may be doing this if we keep our 303 and have to replace our current panel. One owner has done this already but I do not recall who it was. Maybe it was John Jkwilson ?

Here is the link to the RV panel on Anderson Brass site: https://www.abcorv.com/

Dan

Though I have the brass valve, I haven’t changed it yet.

[TedS]

9200arv.pdf


This is what I put in the Bighorn trailer I had years ago. I don't know if the valve is still available.

[FirstAscent]

A number of us having been communicating here and elsewhere about the new and highly improved "all brass" Kantleak panel by Anderson Brass. I may be doing this if we keep our 303 and have to replace our current panel. One owner has done this already but I do not recall who it was. Maybe it was John Jkwilson ?

Here is the link to the RV panel on Anderson Brass site: https://www.abcorv.com/

Dan

I didn't have my notifications set and just saw all the new responses, thanks everyone! I've definitely heard of the Kantleak system before but nothing good about it. But yes that was the older plastic design. I just looked at their site, thanks Canyonlight for the link, and the all brass system looks pretty great. Two valves, compact, all brass, I like it. I think I may go this route because it seems to meet all my requirements.

[Edit] Looking a little closer, one thing I do not like is that each connection uses a typical garden hose thread, I would've preferred NPT, I wonder if they offer any options. Probably not, but I'll have to call them to see.

[Cate&Rob]

FirstAscent

Those are not garden hose thread connections. They are half inch compression seal connections.

Rob

[TedS]

FirstAscent the fitting ends are npt. They accept the swivel fittings with the cone washers.

[FirstAscent]

This is what they show in the photos on their site which is neither compression or npt haha

[TedS]

Their website was quoted as 1/2" npt. The threads in the picture are most likely straight pipe, not tapered pipe. The female pipe swivel with the cone seal will seal to the ID of male straight pipe.

[TedS]

This is the older plastic which the new brass replaces. Note 1/2" npt.