Best way to install this expansion tank

Help Support Plumbing Forums:

frodo

Just call me Macgyver
Professional
Supporting Member
Joined
Sep 28, 2014
Messages
8,118
Reaction score
2,575
Location
right here right now, over there later on.
Ok, I agree that sounds faster as well, I will go with the tee/nipple method. I'll probably get the stainless corrugated since they bend a little easier.

ONE last thing regarding the vent. If you look in the picture, they have that bend and then a short piece of what looks like the thin pipe just used for normal ductwork. I believe that should be a B-vent pipe there, right? I think I will be able to move the tank a little closer to the wall so a straight piece can go from the tank to that 3x5 reducer above without the bend above the tank. I saw some B-vent pipes at the store but they look pretty solid with finished ends. Are you able to cut those, or is there something else I need?

You are by code, allowed the single wall vent pipe AT THE HEATER
It can not be within 6'' of combustible surfaces

to finish the end of the single wall.
insert a piece of pipe in the vent on a 45 degree angle, and you can use that to bend a lip on the pipe
you need a crimping tool to crimp the other end to insert into the double wall B vent
 

wood4d

Well-Known Member
Joined
Apr 1, 2014
Messages
192
Reaction score
39
Location
south jersey
as far as the exhaust goes you need 26g pipe not the cheap aluminum pipe made for dryer vent. You need a 4" elbow and some pipe and that goes into the b vent. Any ac, plumbing supply has it.
 

dman2

Member
Joined
Jun 30, 2018
Messages
23
Reaction score
2
Location
US
By single wall pipe, do you mean like the kind that is there now?

I am putting this in tomorrow and this is in a finished basement with no floor drain. I thought about putting it in a drain pan anyways just to protect from small leaks or to protect the water heater in case there is a flood in the basement. Is this even worthwhile? Do you usually put them in drain pans in finished basements if there is no drain?
 

frodo

Just call me Macgyver
Professional
Supporting Member
Joined
Sep 28, 2014
Messages
8,118
Reaction score
2,575
Location
right here right now, over there later on.

Jeff Handy

Pro Handyman, NOT A Pro Plumber
Joined
Jul 5, 2019
Messages
1,671
Reaction score
289
Location
Chicago suburbs
In the pic from frodo, there looks to be a shut off on both hot and cold, not just the hot. Look closer.

In the past, I only saw shut offs on the cold inlets, and that is because having a shut off on both sides could cause a heater to explode, if both valves were closed while the heater was heating and if the TPR failed or was absent.

In the past decade or so, I am encountering more customers with shut offs on both hot and cold.

This is very handy for servicing or heater replacement, or when someone has two heaters and you want to just isolate one after a failure until the replacement heater arrives.

But has there been a code change to allow this, or was it always allowed?
 

dman2

Member
Joined
Jun 30, 2018
Messages
23
Reaction score
2
Location
US
Ok, I got it in! First of all, I could not find a 12" stainless line but did find an 18". Is the bend ok on the cold water side?

I am getting a real small drip out of some of brass fittings that the expansion tank is connected to. Will those stop on their own after a little while or do I need to take it all apart and make it even tighter or put something other than teflon tape? Thanks again for all the help.

 

bartleyhs

Well-Known Member
Joined
Jan 17, 2020
Messages
45
Reaction score
5
Location
oregon
In the pic from frodo, there looks to be a shut off on both hot and cold, not just the hot. Look closer.

In the past, I only saw shut offs on the cold inlets, and that is because having a shut off on both sides could cause a heater to explode, if both valves were closed while the heater was heating and if the TPR failed or was absent.

In the past decade or so, I am encountering more customers with shut offs on both hot and cold.

This is very handy for servicing or heater replacement, or when someone has two heaters and you want to just isolate one after a failure until the replacement heater arrives.

But has there been a code change to allow this, or was it always allowed?
Yes, I see both shut offs now. sorry, my mistake.
 

Jeff Handy

Pro Handyman, NOT A Pro Plumber
Joined
Jul 5, 2019
Messages
1,671
Reaction score
289
Location
Chicago suburbs
dman, you stated that you bought a five gallon expansion tank.
The tank you installed is 2.1 gallons.

Then, after asking for advice, you totally ignored that advice and installed your tank basically the way you first had suggested.

And you mentioned that the big box stores advice was different from what you got from here.
As though you felt advice on here was wrong.
Then you just followed your own hunch anyway.

Something in your whole story does not add up.
If you were my customer I would be hurrying out the door, hoping your check cleared, and never coming back.
 

dman2

Member
Joined
Jun 30, 2018
Messages
23
Reaction score
2
Location
US
Actually, if you look at post #17, I did follow the advice of frodo who is really the only one here that gave me useful info when he said:

"I gave you 2 different ways to hang the tank.
either way works.
you need to choose which of the 2 works best for you.

I think using a tee and nipple is faster , neater, than flex to the wall
that is just a personal opinion"

So yeah, I did listen to him and installed it the way he did it, not on my own hunch. And I didn't see anywhere here where everyone said to use a 5 gallon. In fact, someone just said "be sure to size your tank according to mfg's specs, I believe it is 4.5". Well.. I followed that advice too, as the mfg suggests a 2 gallon for up to a 60 gallon tank which happens to fit much better where I am putting it anyways so I brought back the 5 and got a 2.

Thank you again for those that offered me useful info in this thread.
 

Jeff Handy

Pro Handyman, NOT A Pro Plumber
Joined
Jul 5, 2019
Messages
1,671
Reaction score
289
Location
Chicago suburbs
Here is your quote from post # 5.

“Yes, I do know to match the pressure and I did get a 5 gallon one. Thanks.”
 

Jeff Handy

Pro Handyman, NOT A Pro Plumber
Joined
Jul 5, 2019
Messages
1,671
Reaction score
289
Location
Chicago suburbs
Here is your quote from post # 1

“The most common thing I have seen on the web is to put a tee (is brass best or galvanized?) at the top of the tank, run a short length of pipe out of the side of the tee, put a 90 on the end of that and screw the tank into it. The problem I see with that is if the tank fails and fills with water, there will be all of that stress on the water inlet. Can that be resolved by just placing a block of wood under the horizontal pipe to keep the weight off of the pipe?”

This is exactly what you ended up doing.
 

Jeff Handy

Pro Handyman, NOT A Pro Plumber
Joined
Jul 5, 2019
Messages
1,671
Reaction score
289
Location
Chicago suburbs
Meanwhile, bottom line, it looks like what you did should work fine, so that is what matters most.
 

dman2

Member
Joined
Jun 30, 2018
Messages
23
Reaction score
2
Location
US
You are right, that is all that matters! :) Thank you. I did buy the 5 at first then later learned it might be an overkill so returned it for a 2. Sorry for the confusion. I got some pipe dope now and am going to reassemble that brass section and hope it stops the leak. I had some of the yellow gas thread tape from before and put that on the gas lines and those aren't leaking.
 

Diehard

Well-Known Member
Joined
Aug 19, 2017
Messages
2,640
Reaction score
469
Location
North Reading, Mass.
....... And I didn't see anywhere here where everyone said to use a 5 gallon. In fact, someone just said "be sure to size your tank according to mfg's specs, I believe it is 4.5". Well.. I followed that advice too, as the mfg suggests a 2 gallon for up to a 60 gallon tank which happens to fit much better where I am putting it anyways so I brought back the 5 and got a 2.

Thank you again for those that offered me useful info in this thread.
I assume the advice you received included asking you what your water service pressure was. And the fact that the tank comes precharged at 40 psi and should have its pressure added to match your actual water pressure.
Because I believe it's border if/when the pressure is between 60 and 80 psi.
 

dman2

Member
Joined
Jun 30, 2018
Messages
23
Reaction score
2
Location
US
Yes. I have a brand new PRV (the old one was no longer working) and put a pressure gauge on and after everything settles for a few minutes, it remains at 60 so I filled the tank to 60. It says the max is 80 and the max working pressure is 150.
 

dman2

Member
Joined
Jun 30, 2018
Messages
23
Reaction score
2
Location
US
I appreciate the critique! I was wondering about connecting brass but the manual said those are dielectric nipples so hopefully that means I can connect anything to them. The draft hood that the flue pipe is going into is tapered so the pipe fits pretty snug onto it. Should I put a screw into it like the old one had? And finally, is that upper end of the pipe going to cause a problem? That is as far as I could shove it up in there. And of course that wood was temporary. I have a nicer block there already :) Thank you again for everything.
 

Diehard

Well-Known Member
Joined
Aug 19, 2017
Messages
2,640
Reaction score
469
Location
North Reading, Mass.
Yes. I have a brand new PRV (the old one was no longer working) and put a pressure gauge on and after everything settles for a few minutes, it remains at 60 so I filled the tank to 60. It says the max is 80 and the max working pressure is 150.
I had assumed you may be up to at least 60 psi and considering the potential of being over occasionally, I would call that borderline.

What says the max is 80?
 

dman2

Member
Joined
Jun 30, 2018
Messages
23
Reaction score
2
Location
US
It says the maximum pressure is 150. 80 is the maximum air pressure.
 
2
Top