Found a new valve

[Bbelk]

I found a new valve under the closet on the driver's side (curb side?) of a 2010 27FB classic. I don't have a plumbing map for this thing and I can't see where the pipes go from that valve.

Can someone please tell me what this valve is for?

[pcskier]

Does it disappear in to the floor nearby; and does it stick out underneath the trailer at that location? If so...it's a low point drain for winterizing. The winterizing/plumbing sections of Airstream manuals are notorious for not noting all the low points on various models/sizes.

[Bbelk]

I don't think it is a drain because I found it in the ON position.

[OTRA15]

Originally Posted by Bbelk

I found a new valve under the closet on the driver's side (curb side?) . . .

[ROBERT CROSS]

Curb=right, Street=left huptwothreefour👌🏽

Curb side, rear storage compartment in our classic, LP for the WH supply & shower drain. I believe thats rite...water comes out I know that for sure. 👍

Belay that...I'm not sure,😳, ours is on a single line nowhere near the the bypass lines. It sure appears to be a diverter valve for the WH. Turn the pump on, open some taps and look for drips...not here under your trailer. 😂

Bob
🇺🇸

[Star Ship]

Could it be your water heater bypass valve?

[87gn]

I have a 2013 classic with the same valve. Called the factory and received the plumbing diagram , but factory could not determine the purpose of that valve. It appears to me to be a bypass for the parallel check valve. Mine is open also.

[GammaDog]

The 2010 Classic owners manual (avail online from Airstream) on page F13 says:

"On all units except the front bed models an exterior water service shut off valve
is located inside the lavatory cabinet and can be accessed by either opening
the cabinet doors or removing the cabinet drawers. The front bed models shut
off valve is accessed by removing the access panel on the wardrobe bottom
shelf. The exterior water service is located beyond the heated area of the trailer
and can be damaged if the water is not turned off in freezing temperatures. In freezing temperatures close the shut off the valve and open the exterior water F service valve to drain the valve and line"

That describes it, right?

I'm thinking that "exterior water service" means outdoor shower???? Or maybe your trailer has a spigot? If so, I would winterize by leaving that valve open, opening the shower valves and low point drains. That should clear the lines completely. I would only close that valve if I was using the trailer in sub freezing weather and wanted to empty the section from that valve to the outside.

Page F14 pretty much confirms that. In the winterizing instructions:

"3. Open all drain valves including drain plug or valve on water heater and exterior water service valve. (See drain valves on previous page)"

In your pic it appears that the furnace duct has been disconnected. Did you do that to access the valve?

[PatLee]

That sure looks like the hot water shut-off valve to me. In your photo, it's in the "on" position (parallel with pipe). When you winterize, you would want to close it (make it perpendicular to pipe). And is that a plastic tube I see - perhaps part of your 'winterizing kit'?

[PatLee]

BTW - I found technical support at Airstream factory very helpful. They sent me the plumbing diagram for my AS and probably have one for your unit as well. Ask them if there are any peculiarities to your unit as cited in other posts on this thread. If you send them the photo, it could help them answer your question more thoroughly.

[Aznomad450]

I own a 91 Excella and discovered a valve in the same general location and it was a manual isolation valve for the fresh water tank autofill system. If I close it the tank will not autofill, but if I open it I can then autofill the tank.

[Bbelk]

[QUOTE=ROBERT CROSS;2170905]Curb=right, Street=left huptwothreefour👌🏽

/QUOTE]

So the door is on the curb side, which is the right side looking forward.

got it....

[Bbelk]

Originally Posted by 87gn

I have a 2013 classic with the same valve. Called the factory and received the plumbing diagram , but factory could not determine the purpose of that valve. It appears to me to be a bypass for the parallel check valve. Mine is open also.

I came up with that too, but it makes no since for that valve to be in the open position unless it was a factory error.

[Bbelk]

Originally Posted by GammaDog

The 2010 Classic owners manual (avail online from Airstream) on page F13 says:

"On all units ......... valve and line"

That describes it, right?

Right

Originally Posted by GammaDog

I'm thinking that "exterior water service" means outdoor shower???? Or maybe your trailer has a spigot?

It does not go to the shower, but it could go to the outside spigot. I think this is probably right. I will go run a test.

[A W Warn]

Originally Posted by Bbelk

I found a new valve under the closet on the driver's side (curb side?) of a 2010 27FB classic. I don't have a plumbing map for this thing and I can't see where the pipes go from that valve.

Can someone please tell me what this valve is for?

In your manual on page F-8 there is an explanation.
(read about exterior water service)
https://www.airstream.com/wp-content...lassic2010.pdf

[ROBERT CROSS]

Could it be a mixing valve?
The heaters don't have an an adjustable thermo to control water temp, maybe it's a way to add cold water to the output of the heater. 🤓

Bob
🇺🇸

[Bbelk]

I ran a test. I turned on the faucet outside and let it run. I went inside and attempted to close the mystery valve to see if the faucet shut off. The valve is defective and would only turn about a third of a turn, and not quite the full 90 it would take to be off. There was no detectable change in the flow rate. I did some more checking and determined for sure that this valve is exactly parallel to some device that looks like a check valve. If it is a check valve, I have no idea which direction it blocks and it doesn't really matter since the valve is stuck open. So I am going back to pretending I don't know that valve is there. I have gotten away with it for five years.

Thank you for the guidance and the owners manual and I now know what "curb side" means. Also, someone asked about the heater duct that is disconnected in the picture. It fell apart the first time I reached my hand down there. The metal "T" was not pushed in far enough to reach the hose clamp.

[GammaDog]

I would not let either of those findings dissuade you from believing that it is what the owners manual says it is. Moving a valve 1/3 of the way from open to closed may have no noticeable effect on flow. As for the check valve, it may be just that. In residential plumbing systems any exterior faucet or spigot is required to have a backflow preventer. That keeps water from being forced or siphoned into the drinking water system from what is intended to be an outlet. The in-line device you see could easily be that.

[Bbelk]

Originally Posted by GammaDog

I would not let either of those findings dissuade you from believing that it is what the owners manual says it is. Moving a valve 1/3 of the way from open to closed may have no noticeable effect on flow. As for the check valve, it may be just that. In residential plumbing systems any exterior faucet or spigot is required to have a backflow preventer. That keeps water from being forced or siphoned into the drinking water system from what is intended to be an outlet. The in-line device you see could easily be that.

A check valve in parallel with a normally open valve does not do anything. If it is a backflow preventer, why would Airstream provide a means to bypass it and then leave that valve in the bypass position.

Brad

[Adiredneck]

In our '14 27FB Classic, that turns off the outside water spigot. I leave it open when winterizing, blow it dry (as I do with every spigot, toilet and showers), and then pump RV anti-freeze through them all. Belt and suspenders, I know, but I'm already chasing one water problem, don't need another...