Expansion tank size

[Patti]

Hi-Need some input- I have an older Tarm Solo 140. I’m putting 1000 gal water storage tank in, (so about 1250 gallons of water total). What size of expansion tank do I need?
Someone told me 80-100 gallons- is that accurate?
I know nothing about bladders- should the expansion tank have a bladder or does it matter?
Thanks. Patti

 

[PassionForFire&Water]

Around 10% of acceptance volume, or 125 gal
It needs to be an expansion tank for heating applications, not potable water

 

[maple1]

Google 'sx90v'. I have 2 of those (2 different manufacturers) for my system, and its 2/3 the size of yours. So 3 for yours. I found that size to be the best balance of volume per $, when I was looking. You might get away with a big non-bladder tank, if you can orient it high (higher than your system), and a ways away from it. Otherwise you will inevitably end up with some air in your system. I started out with a 110 gallon LP tank, but eventually gave up and went bladder. Mine was on the floor close to my system though.

 

[Patti]

Around 10% of acceptance volume, or 125 gal
It needs to be an expansion tank for heating applications, not potable water

Okay, thanks. Good to know that rule of thumb.
I actually got a response from Amtrol too, and the rep said ~100 gallon would work. Thanks again for your input! Patti

 

[Patti]

Google 'sx90v'. I have 2 of those (2 different manufacturers) for my system, and its 2/3 the size of yours. So 3 for yours. I found that size to be the best balance of volume per $, when I was looking. You might get away with a big non-bladder tank, if you can orient it high (higher than your system), and a ways away from it. Otherwise you will inevitably end up with some air in your system. I started out with a 110 gallon LP tank, but eventually gave up and went bladder. Mine was on the floor close to my system though.

Hi! Thanks for your input.
My buffer tank is upright and goes pretty much to the ceiling. I’m not sure how my plumber/HVAC guy is planning to install the expansion tank…🤷‍♀️
I know nothing about plumbing …but I’ve always ‘assumed’ that because of the ‘heat rises’ principle, that expansion tanks HAD to be higher than your system.

You said yours were on the ground, so I’m assuming that the presence of a bladder allows it to be situated in other places-not necessarily higher than the system.
Have I assumed correctly?

Man these little buggers are expensive- and yup- I’m finding out… the bigger you go…the bigger you go $$$$🫤
So I’ll check those models out, thanks!
The only thing is that I purposefully searched and searched for an upright tank in order to save floor space, and if I have to put three units in, then I may be undoing what I just went to great lengths to do!
Perhaps they could be mounted up high on the wall beside the buffer tank. But…we shall see!!
BTW…if memory serves me correctly, you are from Nova Scotia, aren’t you?
How did you fare through Fiona?
Craziness😢….and Florida….😢that’s just beyond crazy.
Thanks again for your input!
Patti

 

[maple1]

Hi! Thanks for your input.
My buffer tank is upright and goes pretty much to the ceiling. I’m not sure how my plumber/HVAC guy is planning to install the expansion tank…🤷‍♀️
I know nothing about plumbing …but I’ve always ‘assumed’ that because of the ‘heat rises’ principle, that expansion tanks HAD to be higher than your system.

You said yours were on the ground, so I’m assuming that the presence of a bladder allows it to be situated in other places-not necessarily higher than the system.
Have I assumed correctly?

Man these little buggers are expensive- and yup- I’m finding out… the bigger you go…the bigger you go $$$$🫤
So I’ll check those models out, thanks!
The only thing is that I purposefully searched and searched for an upright tank in order to save floor space, and if I have to put three units in, then I may be undoing what I just went to great lengths to do!
Perhaps they could be mounted up high on the wall beside the buffer tank. But…we shall see!!
BTW…if memory serves me correctly, you are from Nova Scotia, aren’t you?
How did you fare through Fiona?
Craziness😢….and Florida….😢that’s just beyond crazy.
Thanks again for your input!
Patti

Fiona was pretty bad, but we ourselves were ok, and lucky, relatively speaking. Others north and east of us were worse, and Ian down south was/is another level all together. I absolutely hate hurricanes.

Bladder expansion can go anywhere you can find a place for it. Just need to connect to system. Non-bladder should be up as high as you can get it. I briefly considered our upstairs bedroom, but no way that was going to fly. An attic might be a consideration but it would need to be well insulated. The second bladder tank I got was a lot cheaper than the first. Forget the brand. Got it a local supply place. Not home right now. I'll try to remember to check and post the brand when I get back.