Replaced the wet bay "shower" valve today

[J&JD]

Clean-looking install, @J&JD! Do you have a link to the source for the external backflow preventer you used. I might want to add the second one as a double-check in case the OEM were to fail.

TJ

It is either this one or one very similar. It’s been awhile since I purchased the unit.

https://www.amazon.com/dp/B000DZHA7S/?tag=rvf01-20

There is a quick disconnect on each end of the hose so I can attach the hose to the tank rinse or attach to the outdoor faucet for filling a bucket. One advantage of this tank rinse system is that the rinse doesn’t go through the water filters. No big deal but makes sense to me.

 

[TJ&LadyDi]

It is either this one or one very similar. It’s been awhile since I purchased the unit.

Robot Check

There is a quick disconnect on each end of the hose so I can attach the hose to the tank rinse or attach to the outdoor faucet for filling a bucket. One advantage of this tank rinse system is that the rinse doesn’t go through the water filters. No big deal but makes sense to me.

It looks like that one has the auto-drain feature. Does it release water into the wet bay when you turn the water supply off? I'd like to find something that is not vented so I don't get water in the wet bay.

TJ

 

[J&JD]

It looks like that one has the auto-drain feature. Does it release water into the wet bay when you turn the water supply off? I'd like to find something that is not vented so I don't get water in the wet bay.

TJ

Actually, that is not a problem for some reason (maybe because of the other back flow further up the line). There is more liquid from the tank rinse disconnect than from the back flow valve. For $6 worth trying.

 

[TJ&LadyDi]

I have decided to go with a Camco 1/2" IPS backflow preventer...

https://www.amazon.com/dp/B000EDUTN6/?tag=rvf01-20

...and a set of 1/2" IPS to 3/4" GHT adapter fittings as a backup to the Newmar-installed backflow preventer.

https://www.amazon.com/dp/B07GD8ZWF6/?tag=rvf01-20

The Camco unit is not a self-draining backflow preventer and I feel a bit more comfortable not having the possibility of water draining into the wet bay. I will put the assembled unit on the end of the short hose between the new valve set and black tank flush input fitting with quick-couplers at each end. Will post a photo when completed.

This is probably overkill, but will provide an additional comfort factor.

TJ

 

[sheridany]

I bought these and haven’t used them yet. So behind on my mods. I thought about putting this in front of the quick connect @TJ&LadyDi shared on his mod to his wet bay that I just got. I am no plumbing expert but it seems like good insurance maybe?

Mueller/B & K 108-904RP Backflow Preventer-Vacuum Breaker (2 Pack) Robot Check

 

[TJ&LadyDi]

I bought these and haven’t used them yet. So behind on my mods. I thought about putting this in front of the quick connect @TJ&LadyDi shared on his mod to his wet bay that I just got. I am no plumbing expert but it seems like good insurance maybe?

Mueller/B & K 108-904RP Backflow Preventer-Vacuum Breaker (2 Pack) Robot Check

@sheridany, do those backflow preventers have drain holes around the male end? I notice the description says it has a "manual drain" and that would be OK for my use. I just don't water spraying out of the drain holes when the water is shut off. Those look like nice, compact units.

TJ

 

[sheridany]

@TJ&LadyDi mine are in the rig but I think they do have drain holes and as I read the review there was a video and a picture of what looks like they spray water all over when the pressure drops. Is that how they are supposed to work?

 

[TJ&LadyDi]

The vented units are designed to release water pressure externally when the tap is turned off. Supposedly, that is to prevent them from freezing up in cold weather. Since my wet bay should never experience freezing conditions, I am going with a non-vented, inline 1/2" IPS backflow preventer and adapter fittings to 3/4' hose thread. It is a little bulkier and a bit more expensive, but won't release water into the wet bay.

Some have not had issues with the vented add-on units releasing water and the speculation is that the Newmar-installed backflow preventer in the tank rinse system is working as it should. I think that is distinctly possible. Since, however, my reason for adding a second backflow preventer is primarily to have a backup in case the Newmar-installed one fails, I prefer not to have one that could vent contaminated water into the wet bay. Overkill, to be sure, but in the case of preventing fresh water contamination, I am all for "overkill.

TJ

 

[J&JD]

OTOH @sheridany & @TJ&LadyDi , since I have had no issues with water spraying from the my added back flow maybe this device is a good indicator that the Newmar unit is performing correctly?.

 

[TJ&LadyDi]

I just noticed something that has been hiding in plain sight; the tank rinse low point drain. (See photo of my install on Page 1)

Of course, I use it to winterize my coach, but it just occurred to me that I could use it to release pressure before disconnecting the hose. Duhhhhhh!

Turn the water supply off and a simple twist of the valve handle should release all pressure in the tank rinse system. That should help avoid any release of liquid into the wet bay, even with one of the vented (self-draining) backflow preventers. Why didn't I think of that?

Guess it is back to Amazon for one of the backflow preventers recommended by J&JD and Sheridany.

TJ

 

[sheridany]

I am also focused on the outside water source hooked up to the rinse in addition to @TJ&LadyDi mod What can I do to release the pressure in the hose lime so it doesn’t spray everywhere?

 

[TJ&LadyDi]

I am also focused on the outside water source hooked up to the rinse in addition to @TJ&LadyDi mod What can I do to release the pressure in the hose lime so it doesn’t spray everywhere?

Do you have a tank rinse low point drain? If so, it should work just the same. Turn the water source off and then use the low point drain to release the pressure.

TJ

 

[J&JD]

I am also focused on the outside water source hooked up to the rinse in addition to @TJ&LadyDi mod What can I do to release the pressure in the hose lime so it doesn’t spray everywhere?

Not sure which hose you are addressing. If you are using a short hose hookup to the new shower valve setup or to a setup like mine, as soon as the shower valve or in-line valve in mine is closed the rinse water pressure is immediately released into the tank and when you release the quick disconnect at the tank rinse connect the short hose will not spray and a small dribble will release out of the tank rinse connection.
If you are asking about at the hose bib at the shore water hookup, I simply always use a “Y” connector and crack the second “Y” valve after shutting off the hose bib.

 

[J&JD]

I just noticed something that has been hiding in plain sight; the tank rinse low point drain. (See photo of my install on Page 1)

Of course, I use it to winterize my coach, but it just occurred to me that I could use it to release pressure before disconnecting the hose. Duhhhhhh!

Turn the water supply off and a simple twist of the valve handle should release all pressure in the tank rinse system. That should help avoid any release of liquid into the wet bay, even with one of the vented (self-draining) backflow preventers. Why didn't I think of that?

Guess it is back to Amazon for one of the backflow preventers recommended by J&JD and Sheridany.

TJ

TJ, I may be wrong (and as you said that is conferred to me often by the DW) but I don’t think it matters. The tank is vented and the rinse line ends in the vented tank area. So as soon as you turn the source valve off the line pressure drops to zero almost immediately. By opening the drain valve you will be draining a line with no pressure. The reason you get a back spray out of these back flow preventers is they are releasing the pressure that’s left in the line after the source is turned off. If no pressure no back spray.

 

[TJ&LadyDi]

TJ, I may be wrong (and as you said that is conferred to me often by the DW) but I don’t think it matters. The tank is vented and the rinse line ends in the vented tank area. So as soon as you turn the source valve off the line pressure drops to zero almost immediately. By opening the drain valve you will be draining a line with no pressure. The reason you get a back spray out of these back flow preventers is they are releasing the pressure that’s left in the line after the source is turned off. If no pressure no back spray.

That makes sense, thanks, Ahhh, the part about the vented tank makes sense, not the part about being wrong.

TJ

 

[TJ&LadyDi]

Here's the completed wet bay conversion with custom hose connected to the black tank flush input.

Note the red marking bands on the hose that I use to indicate non-potable water use only. The hose was custom-made by the RV Water Filter Store to a length of 18" (closer to 20" fitting-to-fitting). It was a bit pricey ($25) but fit exactly as I wanted with no extra length to deal with. The hose will be disconnected and stored in the wet bay when not in actual use. Quick-disconnect hose fittings on both ends will facilitate the process.

TJ

 

[sheridany]

@TJ&LadyDi That looks awesome. I am waiting for a couple more parts to arrive to do this same one as well. Very well done.

 

[TJ&LadyDi]

@TJ&LadyDiI am waiting for a couple more parts to arrive to do this same one as well.

When you connect the existing 1/2" supply hoses to the back of the new mixing valve, you may have to add a rubber washer inside the female fittings to ensure a leak-free connection.

My original supply fittings bottomed out on the extra-thick nuts securing the mixing valve in place. I managed to snug mine up just enough to get a leak-free connection, but it was close. I'm thinking about going back and adding the extra washers just for safety. The other alternative would be to find thinner backing washers and/or nuts. Both are thicker than I think is necessary.

TJ

 

[sheridany]

Paging Dr. @TJ&LadyDi we are working on the wet bay faucet change out. Do you know if the valve is left facing out if it hits the bay door or not when closing. We created a plate to put in place off the extension that sticks out from the bay wall. But I am thinking we leave it as is like you have yours.

you can clearly see we are trying to over engineer a simple mod.

 

[TJ&LadyDi]

Paging Dr. @TJ&LadyDi we are working on the wet bay faucet change out. Do you know if the valve is left facing out if it hits the bay door or not when closing. We created a plate to put in place off the extension that sticks out from the bay wall. But I am thinking we leave it as is like you have yours.

you can clearly see we are trying to over engineer a simple mod.

View attachment 2605

Mine just barely clears the bay door in the full, swiveled out position. I always swivel it in before closing the bay door, however. And, remember, we are talking about different models of coach here. I don't know it that makes a difference, but it could.

The plate idea looks good and should provide some good support.

TJ