Expansion Tank Installation--horizontal with flex pipes

[Dallin Lewis]

I installed an A.O. Smith water heater with a friend (handier than me) a few weeks back. There's intermittent leaking at the T/P valve, and I'm confident that I need to install an expansion tank (the old heater had one, but it is not reusable).

My question is whether I can work with the flex pipes and shelving I already have. Our water heater is in the closet under the stairs, which we've converted to a pantry. We have shelves built right next to the water heater. I'd like to set the expansion tank horizontally on that shelf where the Sunmaid box is, and get a second flex pipe and a valve that will go from the cold water line to the expansion tank, and then use the current flex pipe I have (or something shorter, if necessary) to connect it to the heater. Because the shelves go right up to the drain pan, I could position the expansion tank so that the point of connection is above the drain pan, in case there are any leaks. I've checked using the old expansion tank, and there is plenty of room on the shelf, and it would rest right under one of the shelving brackets.

Any problems I'm not foreseeing? I'll post a picture of the old set-up with the old water heater/expansion tank too, in case that's helpful.

Thanks in advance.

 

[hj]

The tank can go ANYWHERE in the system, but ideally after the water heater's shut off valve.

 

[Sponsor]

 

[Dallin Lewis]

Good point. Unfortunately, the water heater doesn't have its own separate shut-off valve--the old set-up didn't have one either (I bought the house a couple of years ago). To shut off the water heater, I have to turn off the main water line (which is fortunately very accessible).

 

[Jadnashua]

The orientation of the tank does not affect its operation, so it could go on the shelf. Since it will eventually fail, it's nice to have the connection on the top side so that when you remove it, it doesn't empty its contents (maybe 5-6 gallons or so) all over the place. Because when it fails, it will become quite heavy, you want it somewhere it can be supported well. Full of water after the bladder fails, it could be close to 50#...not something you want sitting there unsupported well.

 

[Dj2]

1. You need a shut off valve on the cold side. That's code.
2. You may have a leaky T&P valve, so replace the one you have with a new one - it may solve your leak.
3. Do you have a pressure reducing valve - usually located where the main comes into the house. Measure your house water pressure (at the cold side on your washing machine and at a back yard hose bib). If your reading is over 80 psi, you need a new PRV.

 

[Dallin Lewis]

The orientation of the tank does not affect its operation, so it could go on the shelf. Since it will eventually fail, it's nice to have the connection on the top side so that when you remove it, it doesn't empty its contents (maybe 5-6 gallons or so) all over the place. Because when it fails, it will become quite heavy, you want it somewhere it can be supported well. Full of water after the bladder fails, it could be close to 50#...not something you want sitting there unsupported well.

Great, thanks! Good point about pointing the connection up.

 

[Dallin Lewis]

1. You need a shut off valve on the cold side. That's code.
2. You may have a leaky T&P valve, so replace the one you have with a new one - it may solve your leak.
3. Do you have a pressure reducing valve - usually located where the main comes into the house. Measure your house water pressure (at the cold side on your washing machine and at a back yard hose bib). If your reading is over 80 psi, you need a new PRV.

#1 That's good to know about the shut-off valve. There wasn't one on the original set-up, so I didn't know to install one.
#2 Could be, but I'm pretty certain it's not having an expansion tank. At least, I want to start there--the water heater is only weeks old.
#3 I can't see a pressure reducing valve anywhere, but I'll make sure to test the house water pressure.

Thanks for responding.