Question- Are there 'opposite (left and right) 3 way bypass valves?

showme-MOC

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I'm in the process of revitalizing the water heater in our 2000 Montana. We've had this for about 5 years and have it parked on our property we plan to build a house on, but I've never used the plumbing in it yet, as it's mainly been for work breaks and tool crib. When I started checking things out, I found that there is a 3 way bypass at the cold inlet, but there isn't one at the hot outlet side. When I started looking, I found that there was an elbow and a 3" tail coming out of it that had been cut. Someone then did the hot bypass by just adding an elbow to the hot water outlet line and connecting it to the inlet bypass valves' vertical pipe, therefore shutting down any use of the heater. I'm assuming the heater is bad, and that's how it ended up like this. I plan on installing a 3 way bypass valve on the outlet side, too, but here's my problem.

I ordered a set of two valves and have found that they are both directional (the same direction) and can't be reconfigured by pulling the guts and spinning them 180*. These will work on the inlet side, but the only way I can get one to work at the outlet side is to turn it around and have the valve handle face the water heater. This would be a very tight fit and a hassle to work with. I have searched everywhere for an opposite valve, and I can't find one anywhere! I can't believe they wouldn't make a "right and left hand" set of valves. I've read that the water heater "may" have a check valve, but I'd rather be certain.

Does anyone know where I can find opposite 3 way bypasses for 1/2" pex that would work? Thanks in advance for any help on this. Lee
 
With a three way valve and a check valve in the hot water outlet, there is only 1 valve needed, see the diagram below. There is a check valve in the hot water outlet.
1748034914049.png
 
Last edited:
No manual valve is needed at the heater outlet. The Bypass valve either allows cold water to enter the heater (and thus get hot), or it bypasses the heater entirely and feeds directly to the outlet without getting heated. In the system described in Kirk's reply, there is always a check valve at the tank outlet. It's purpose is to prevent water from flowing back into the heater tank when the valve is in the Bypass position. The outlet check valve serves no purpose in the normal (not Bypass) mode.

Return the second valve for a refund.
 
Here you see the brass check valves on both inlet and outlet of the water heater tank, as described by Kirk and Gary. Looking closer you see someone has added the unnecessary(if the hot water check valve is good) 2nd valve in the hot water outlet line.

1748050137651.jpeg
 
Here you see the brass check valves on both inlet and outlet of the water heater tank, as described by Kirk and Gary. Looking closer you see someone has added the unnecessary(if the hot water check valve is good) 2nd valve in the hot water outlet line.

View attachment 1314066
Hard to tell if there is a check valve there or is it just a brass nipple
 
When I started looking, I found that there was an elbow and a 3" tail coming out of it that had been cut. Someone then did the hot bypass by just adding an elbow to the hot water outlet line and connecting it to the inlet bypass valves' vertical pipe, therefore shutting down any use of the heater.
If none of the replies above help you, post a picture of what you have so that we can be sure.
one-bypass.jpg
 
Thanks, everyone. I wasn't aware that there is a check valve at the hot water outlet of the tank. I went ahead and rebuilt what was needed without a hot side 3 way by-pass. But, and I'm not completely sure what I was looking for, but when I shined a light into the tank through the hot water brass fitting, it didn't look like anything was there, as in a check valve. Maybe I just wasn't seeing it. This is a 2000 model, and since we'v e only owned it 6 years, it may have been replaced already, but were the check valves present in 25 year old water heaters? I plan to replace this one soon anyway, but if there is a check valve at the exit fitting of the tank, I couldn't see it. But I did get the new fittings and pex lines installed where needed, and have no leaks, so it's good so far. I did find while filling the fresh water tank that the new fill hose I put in was leaking a bit at the tank entry, but I tightened that up. The drain fitting was loose, so I pulled it out and checked it then applied some silicone caulk to the threads. It had teflon tape on it when I took it out, and was about to switch to plumbers' pipe dope, when I read on the pipe dope tube 'do not use on plastic threads'. Seeing that the teflon tape hadn't kept it secure, I opted for the silicone. I'd also read in a post where one owner suggested putting a thin layer on the fill hose connections, too. I think if I'd done that it would have solved the tank fitting leak, so I may go back and do that, although a leak at that point only affects it when filling the tank, so it's not imperative but will be done anyway. Thanks again for your help on this, folks. Lee
 
were the check valves present in 25 year old water heaters?
The check valves are not part of the water heater but are added when installing it. They just look like a nipple and can be either metal or plastic.
1749403012572.png
1749403048200.png

'do not use on plastic threads'.
If the drain plug is nylon, it means that you have an Atwood water heater. It is a good practice to replace those drain plugs on a regular bases because they do sometimes break when removing them. It can be a real challenge to get what stays in the water heater out without damaging the threads. I know from experience.
 
Thanks, kirk, that helps. I'm thinking that this heater only has the brass fitting with no check valve. At least none that I can see, because I can shine the light directly into the tank right now. I need to get one installed, then I'll transfer it over to the new tank. But I'm not even turning the water heater on right now, since there's no need for it yet.
RayIN, thanks for that tip, too! I've seen those before but never knew what they were for, but that is one question I asked myself when I was under the trailer checking out the tank. What happens if a bushing goes bad? Thanks!
 

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