Expansion Tank install options with up connection

[Eljay]

We moved into a home with a PRV but no water heater expansion tank. Leaks around the house have made installing an expansion tank a priority. Better late than never.

I see many folks installing tanks horizontally with/without straps or vertically with the connection down. I'd just like to play it as safe as possible and install it vertically with connection up. Making it easier to switch out tanks without taking a bath is an added bonus.

Question 1: What do you all think about the installation options below?

Option A (Blue line): Copper pipe with a straight shot from the cold water line completely across the top of the water heater and then downward to the expansion tank. I don't have much experience running copper pipe for water. But I assume that this would be too long of a run without any added support. I would use a couple of shelf brackets (something like this at home depot) installed at each two available wall studs.
The pipe would be secured to the shelf brackets using copper tube straps.

Option B (Green line): Copper pipe runs along the wall. A 2"x6" would be installed horizontally spanning two studs along the wall. Copper tube straps (home depot) would secure the pipe to the 2"x6" at two points.

Option C (not pictured): Run corrugated copper or steel connectors.

In all scenarios, I'd secure the expansion tank to the wall using one of these brackets:

Storm King Hydroclaw (supplyhouse)
or
Holdrite Quickstrap (supplyhouse)


I assume Option B (green line) is preferred since it will provide the most support when the bladder fails?


Question 2: A MIP adapter is currently installed on the cold water supply shutoff valve allowing connection to the water heater with corrugated steel flexible hoses. Ideally, I know it should be removed. But I don't have much experience unsoldering copper fittings, especially in such an awkward space so close to the wall. Could I just screw on a FIP adapter and go from there?

 

[Master Plumber Mark]

you need to put up some pictures....
if you dont know how to solder then its gonna be
a struggle to get it the way you want


their are many ways to support a thermal expansion tank

 

[Sponsor]

 

[Eljay]

you need to put up some pictures....
if you dont know how to solder then its gonna be
a struggle to get it the way you want


their are many ways to support a thermal expansion tank

I can solder. I just don't claim to be good at it.

I've recently soldered about a dozen joints installing a water softener with 1" pipe. The joints definitely aren't pretty. But they don't leak.

Do these pictures help?

 

[Master Plumber Mark]

If you are saving the water heater this is pretty easy peasy... The heater has those flex
connectors on it and you should just have to un hook the cold side and install a 3/4 brass tee
and then some brass nipples and set it up something like in the picture below...

the work I am looking at is pretty rough looking, but the flex connectors are ok, just a little
shabby in appearance... We have used hundreds of them over the years and they seem to
work very well....

the t+p drain looks rough with the flex connector in the line.... I suppose it will work properly
but it looks like crap....

If your flu pipe off the heater is aluminium dryer vent pipe it ought to be changed out to heavier guage
steel flu pipe...

look at my web site on yelp and you will see some installs with the tanks and tees

https://www.yelp.com/biz/weilhammer-plumbing-indianapolis-3


Tank note that we installed this therm tank with galvanized pipe instead of brass fittings
I suggest the brass fittings will last longer... we have switched to the brass ones
you support the therm tank arm with
a wedge between the top of the heater and the arm.....

 

[Eljay]

If you are saving the water heater this is pretty easy peasy... The heater has those flex
connectors on it and you should just have to un hook the cold side and install a 3/4 brass tee
and then some brass nipples and set it up something like in the picture below...

...

look at my web site on yelp and you will see some installs with the tanks and tees

https://www.yelp.com/biz/weilhammer-plumbing-indianapolis-3


Tank note that we installed this therm tank with galvanized pipe instead of brass fittings
I suggest the brass fittings will last longer... we have switched to the brass ones
you support the therm tank arm with
a wedge between the top of the heater and the arm.....

Thanks, Mark.

Won't the the brass fittings still eventually corrode at the water heater? If they don't leak, would stainless steel 304 or 316 threaded fittings be better (though I have read that there are issues with galling)? I had seen pictures of folks using fittings at the water heater with and without a wedge to support the fittings. I hadn't seriously considered going that route since I was worried that the water heater wasn't designed to support 50+ lbs once the bladder fails and tank fills up with water. But if the pros have been doing it this way, I guess I shouldn't worry.

My original idea is similar to this.

But I also wanted to support the pipe as well using tube straps and the like. I'm pretty green when it comes to this plumbing stuff. But my work has taught me to eliminate single points of failure when possible. I liked the idea of clamping the expansion tank to the wall. If that somehow fails, I also thought it might be a good idea to support the pipes as much as possible and screw them to the wall. It's fairly common for us to not be home for few weeks. I'd hate to come back to a flooded house if we forgot to shut off the water before leaving.

 

[Master Plumber Mark]

anything to support the tank will work... and any place you have a joint
it potential for a leak sometime down the road...

you can do this any way you wish, the brass tee off the top of the
heater is about the easiest way to do it without making a contest out of it....
This tee will probably last 10 times longer than the heater will and of course
their are old galvanized tees that are over 100 years old still working great out there somewhere.
I think as long as you put a shim under the arm to support the weight I dont think its an issue

carry on as you see fit.....

photo added by Terry Love

 

[Jadnashua]

Avoid galvanized fittings, but the tank can actually be mounted in lots of places in any orientation. As long as it's between the WH and the cold shutoff, it should be fine. You do want to be able to access the air valve on the bottom in case it needs a little fill up sometime later.

 

[Clog]

Eljay,

It could be an optical illusion, but the example photo you posted above (requoted below) appears to have the expansion tank tee'd off of the cold water supply before the shut off valve. If so, then the water to the entire house would need to be shut down before servicing the expansion tank. By "servicing", that not only includes removal and replacement in the event of failure... it would also include something as simple as adding air pressure to the tank if at some point it becomes necessary.

The particular tank shown is from Watts, and the Watts instructions state that air pressure should be adjusted without water pressure acting on the water side of the bladder. Watts strongly emphasizes this. I would imagine other expansion tank manufacturers might recommend the same practice. So again, with the plumbing arrangement as it appears below, water pressure to the entire home would have to be relieved first before adding air to the tank.

On the other hand, if the shut off valve to the water heater preceded the expansion tank, where the expansion tank were plumbed in between the water heater and the shut off valve as recommended by Jim in the post above, then water that serves the house could remain on and functional, while only the shut off valve to the water heater is turned off, which would simultaneously enable the servicing of the expansion tank.

My original idea is similar to this.
.

 

[Eljay]

Eljay,

It could be an optical illusion, but the example photo you posted above (requoted below) appears to have the expansion tank tee'd off of the cold water supply before the shut off valve. If so, then the water to the entire house would need to be shut down before servicing the expansion tank. By "servicing", that not only includes removal and replacement in the event of failure... it would also include something as simple as adding air pressure to the tank if at some point it becomes necessary.

The particular tank shown is from Watts, and the Watts instructions state that air pressure should be adjusted without water pressure acting on the water side of the bladder. Watts strongly emphasizes this. I would imagine other expansion tank manufacturers might recommend the same practice. So again, with the plumbing arrangement as it appears below, water pressure to the entire home would have to be relieved first before adding air to the tank.

On the other hand, if the shut off valve to the water heater preceded the expansion tank, where the expansion tank were plumbed in between the water heater and the shut off valve as recommended by Jim in the post above, then water that serves the house could remain on and functional, while only the shut off valve to the water heater is turned off, which would simultaneously enable the servicing of the expansion tank.

Clog, You're right about that photo. Definitely not your eyes playing tricks on you. Our house's plumbing isn't the same way. And I've teed off the expansion tank after the shutoff valve. But good heads up for folks who might've glossed over that part in the manual. I wonder how many bladders have busted prematurely as a result people adjusting the air charge while the tank is in service.

 

[Jadnashua]

RE adjusting the precharge on the tank...all one has to do is read the instructions, but how many people actually do that?!