Water heater shut off valve...where is it?

[ole81]

OK...our water heater was leaking...the floor was wet behind the pump and the tank...so we ordered a new unit which will be delivered tomorrow.
At the moment, we are in Galveston.
About 5 minutes ago Gail said there was no pressure at the sink.
I went to the bathroom at the back and the carpet was soaked.
I ran outside and water was gushing out from under the heater area...so I immediately shut off the gas to the heater and the city water supply to the entire unit.
My immediate question is....where do I shut off the supply to the water heater tank and still provide water to the kitchen and commode?
Unfortunately, the 1980 Airstream Service Manual is not specific.
Right behind the tank is a tan valve...does this shut off the supply? or is it a valve in the external rear compartment?

[JFScheck]

You are looking for a divert valve, looks like lower right inline grey....

[jcanavera]

If you have a water heater bypass, engage that. Usually this closes off the cold water input to the tank, the hot water exit from the tank, and opens up a bypass pipe that moves the water from cold directly into the hot water side. If you normally winterize your trailer, it means closing two valves and opening a third.

Doing this will isolate the hot water tank but will keep water flowing through both the cold and hot water outlets (although hot water outlet will discharge cold water).


Jack

[ole81]

Many thanks for the prompt responses.
1. I don't know that I HAVE a divert valve. Could it be the valve in the picture that I attached?
I have never found the need to 'winterize' as we are near Houston and Ole81 spends the non-traveling time in our hangar.
There are two similar valves in the rear exterior compartment.
Am attaching the plumbing diagram in the shop manual....
Thanks again...

[jcanavera]

I looked at your first picture and typically if you follow the pipes going into and out of the water heater you should run into a valve. The cold water pipe usually enters the tank low and the hot exits towards the top. Shutoffs may be present on each pipe as you move away from the tank or worse case at least on the cold pipe. If there is bypass piping, that valve is further away from the tank tied to a pice of pipe that connects the cold and hot water lines together. That pipe is "upstream" from the hot and cold water shutoff valves. Typically it is in the closed position when the input and output valves from the hot water tank are open. When you winterize you close the cold water inlet and and hot water output valves and open the bypass.

Is that plumbing diagram labeled? I see numbers and letters that should correspond to a description.

Jack

[jcanavera]

While I know this isn't your trailer, here is a picture of water lines and a bypass from another Airstream. You will see the 2 valves on the right. One cuts off the water going into the hot water tank, the other shuts off the output from the tank. The single valve on the left is the bypass and typically is in the open position when the other 2 valves are closed. Hope this logically explains it better.

Jack

[ole81]

The shop manual is for 1980 water distribution system 31' rear bath is in our manual with is for the 1980....but has a blue label on for the 1981 Supplement...which I do not find....so I assume the '80 and '81 are virtually the same.

[NevadaGeo]

Or just turn the water pump off, get some water containers and semi Dry camp and relax a while. There'll be valves to isolate the water heater, they always seem to be very hard to see, small and hidden behind another pipe. Need at least two, one for water going into the water heater on the cold side, one for water going into or out of the water heater on the hot side.

Perhaps the leaking water heater is the safety release valve needing reset.

That schematic you show doesn't show valves at your water heater. The valves you show in post #4 are probably dump valves at the rear of the trailer, I suspect those are kept shut until you want to drain all the lines, there may be short pipes beyond those sticking down toward the ground.

[ole81]

I appreciate all the input.
\Unfortunately, virtually all manuals are written by the engineers who develop the system, and are never reviewed by new users.
The page with the diagram lists 2 Stop Valves, 1 Check valve, and 1 Relief Valve....but NO description of where to find them or what the function is.

Here is a full pic of the compartment with the pump and tank. So I will assume that the only valve shown, is the one that shuts off the water into the tank, since the line goes into the lower section.
...but the NEXT question...how do I totally isolate the tank? I see no valve on the top line (output)....so if I use the pump to supply water from the fresh water tank to flush the commode, will it back flow some how into the ruptured hot water tank?

Thanks again for your input...

[jcanavera]

If that valve in the picture shuts off the cold water supply to the hot water tank, you will be fine. Since the hot water tank sends water to the hot water lines in your trailer, if you cut off the (cold) water supply to the tank, the hot water lines will have no pressure. The water pump only pressurizes the cold water system. Hot water is pressurized from cold water entering into the hot water tank and there is only one way for cold water to flow into that tank.

Jack

[NevadaGeo]

I think that valve-line is the street water pressure line into the cold. The green hose from the pump also goes into the same cold line, but any valve on that isn't shown.
So you may be able to shut that valve shown and have street pressure water in the cold line but not be able to run the water pump. Doesn't help if you don't have street water.


oops, we never read the whole thing. You'll have to dump water into the commode using the lady's favorite water pitcher.

[ole81]

OK...I have finally analyzed the plumbing (which I should have done in the first place...) and find that there is a valve missing to keep the tank out of the system.
Since we are planning to install a new tank, I would appreciate if someone could point me to...or provide a good schematic of the preferable bypass system.

Also....am puzzled why our unit has both black and grey lines...is there a functional difference?
Did Airstream use both?
I have been told that I should use PEX lines to fabricate a new configuration.
What are your thoughts????

Bob and Gail

[jcanavera]

Originally Posted by NevadaGeo

I think that valve-line is the street water pressure line into the cold. The green hose from the pump also goes into the same cold line, but any valve on that isn't shown.
So you may be able to shut that valve shown and have street pressure water in the cold line but not be able to run the water pump. Doesn't help if you don't have street water.


oops, we never read the whole thing. You'll have to dump water into the commode using the lady's favorite water pitcher.

Yikes! If that green is from the pump, then you are screwed. Obviously I'd do some changing of that water system once you replace that tank.

Jack

[jcanavera]

Take a close look at post 6 and see how you can adapt that style. If you look closely the two valves, the lower one and the upper one, if you move to the right of those valves that piping terminates in the water heater. So the lower pipe is the cold water input, and the upper is the hot water pipe exiting the heater. So logically turning both valves off isolates the water heater completely from the cold and hot water pipes.

Now look to the left at that valve in the middle of the vertical pipe. That's the bypass valve. This pathway allows you to pressurize both the cold and hot water lines when the water heater input and output valves are closed. If you have this type of setup, you can winterize the lines easily since you can put air pressure in the cold and hot water side from your city water hookup. And in the case of a water heater breach, you can isolate that unit from your water system and still keep pressure in the lines. In your case since the toilet feeds from this area, you would need to move the feed for the toilet to the left side cold water pipe.

So what you need to do is look at your replacement water heater input and output and design the piping, keeping the concepts of that system that I posted within the pipes necessary to fit in the area available.

Jack

[Protagonist]

Originally Posted by ole81

I appreciate all the input.
\Unfortunately, virtually all manuals are written by the engineers who develop the system, and are never reviewed by new users.

I think it's a safe bet that the plumbing system is a retrofit and not Airstream original so the manual wouldn't help you anyway. I say that because you do not have ball valves with lever, oval, or wingnut-style handles, where "handle in line with the pipe" equals on, and "handle crossways to the pipe" equals off, and all you need is a quarter-turn to go from fully open to fully closed. Instead you have a gate valve with a round handle, that you can't tell at a glance is open or closed, and requires several full turns to go from open to closed.

If you rework your plumbing system, use ball valves exclusively; get rid of the gate valves.

[Gregsch]

The valves you show in the first post look just like the valves in my 1979 MH. I think they are original. The black tubing gets old and hard but it doesn't fail. The grey fittings got very brittle and one by one they failed. After several repairs I ended up replacing all the piping with pex. Keep an eye on those fittings, watch for leaks!

[Protagonist]

Originally Posted by Gregsch

The valves you show in the first post look just like the valves in my 1979 MH.

I stand corrected. Thank you. I personally think that ole81 would be well-served by replacing his valves with ball valves if he redoes his plumbing, just for ease of operation; there's a reason why they became standard on later-model RVs.

[ole81]

Oooops!
I made a mistake.....
I removed the hoses from the 12v pump and some time later realized that one fitting appears to be a check valve....but did not note whether it was located at the inlet or outlet of the pump.

Any help would be appreciated.....

Thanks

[Protagonist]

Originally Posted by ole81

I removed the hoses from the 12v pump and some time later realized that one fitting appears to be a check valve....but did not note whether it was located at the inlet or outlet of the pump.

I believe the check valve is on the outlet side, installed so that water will flow out from the pump, but not back into it.

[ole81]

Thanks for the prompt reply....
One more question....
I am using PEX. I have used the ss crimps on most of the fittings, and I know there are copper rings, compression and push together.

Has anyone found any negatives to simply using ss hose clamps and tighten them with a socket and ratchet?
We are not dealing with high pressures.

Bob and Gail