Where to install thermal expansion tank

[Jsmallberries]

Have 50 gallon natural gas water heater installed in the garage.

The old one was on an 18"stand. The new one was installed on a new stand for ease of install with existing plumbing, even though it could have been on the floor since it's a sealed combustion chamber.

How could I fit an expansion tank here? see photo. Plumbing pipe is CPVC

 

[Terry]

I've been using these fittings in brass

3/4 tee
3/4 90
3/4 x 6 nipple
3/4 x 2 nipple

An expansion tank anywhere on the cold side works. I have mine by the front of the garage mounted on the wall.

 

[Sponsor]

 

[Reach4]

Alternate idea:

 

[Jsmallberries]

Thanks for the advice, and Reach4, love that alternative, as I don't have room around the WH and the entry main by the garage door opening is only a short stub out with a brass shut off, don't want to mess with it due to the fact that the builder buried the cinder block bay with mortar in this one section, right where the plumbing main comes up into the wall.

Found this out the hard way

 

[Reach4]

You want to be aware of https://terrylove.com/forums/index.php?threads/tet-deadlegs.86420

As you can see, there is a question discussed there. I think this is not a dead end, but my opinion is not definitive.

You can get drop ear elbows that take 1/2 inch PEX or copper, but have the 3/4 inch thread for the thermal expansion tank.

 

[Jadnashua]

The water will move in and out of the ET during most water heating cycles. Now, it would depend on how long you make the branch. It will not fully empty the ET during a normal cycle. You'll push more water out after emptying the tank and then not using any hot water for awhile. That will fill the ET more, and the next time you use any water (hot or cold), it will push that 'extra' back out into the supply line.

 

[LLigetfa]

It will not fully empty the ET during a normal cycle.

The ET should fully empty during a normal cycle provided the precharge is higher than the water pressure is while being drawn. As to whether the entire "dead" leg contents gets purged/replaced depends on the length of the leg and the volume of water that is pushed by the expansion.

 

[BobbyH]

This is my install

 

[Jsmallberries]

Thanks guys,

I was able to install the tank per Terry's instructions, thought the tank was larger than it is.

Only concern was the new copper flex supply line, had to force it into position, has a slight over bend where it connects to the supply line. Look okay to you?

The incoming pipe is 20 year old CPVC, brittle and weak. These plastic pipe to metal transitions are supposed to be secured, but they're not, I could feel the torque as I tightened it, the concern is the pressure at the elbow below the drywall is a weak point.I was thinking of opening up the wall and re-pipe, or am I over thinking this????

I was changing a water shutoff under the kitchen sink recently, with 2 wrenches in opposite direction as needed to reduce stress on the cpvc supply pipe and the pipe coming up from the slab cracked under the cabinet.

 

[Jadnashua]

You really don't want those galvanized pipe nipples and fittings. They WILL rust and corrode. Yes, I know that brass or bronze fittings cost more, but they'll outlast the house and never rust or leak.

 

[Terry]

His last pictures have the brass fittings.

 

[Jsmallberries]

Do you mean the galvanized stub outs from the top on the heater? One directly connected to the hot water supply, the cold side galvanized threaded stubbi to a brass "T" fitting with nipples and a right angle all brass. There was plastic piece inside the cold water stub out, didn't think I should try to pull it out.

Are you saying i should add dielectric unions to avoid corrosion between the galvanized pipes and the brass?

Anyway, appreciate the comments. All helps all good
Or were you referring to the picture above my post? Not mine

 

[Bannerman]

Do you mean the galvanized stub outs from the top on the heater?

I think Jadnashua is referring to BobbyH's photos in post #8.