2 Gallon Expansion Tanks...Hot water VS Well expansion tank

Discussion in 'Water Heater Forum, Tanks' started by Its.me.again, Oct 12, 2012.

  1. Its.me.again

    Its.me.again New Member

    Oct 12, 2012
    Buffalo, NY
    Can anyone solve this mystery for me? When it comes to putting a 2 gallon thermal expansion tank on a hot water heater, can a person opt to use a 2 gallon well pressure expansion tank?

    What is the difference between these expansion tanks?

    I will use the following example that Lowes sells the 2 gallon hot water tank expansion tank for $40.00 and the 2 Gallon well pump expansion tank for $50.00. These are the "LPT2" series tanks.

    I wonder if most people complain that typical hot water expansion tanks experience bladder failure in 3 years? Do you think that the well style expansion tank has a stronger internal bladder and will last longer?
  2. hj

    hj Moderator & Master Plumber Staff Member

    Aug 31, 2004
    Cave Creek, Arizona
    They should be the same tank, because a 2 gallon "well pump expansion tank" would be absolutely useless for a pump system, (and well pumps do NOT have an expansion problem in the first place).
  3. Sponsor

    Sponsor Paid Advertisement

  4. LLigetfa

    LLigetfa DIYer, not in the trades

    Feb 6, 2011
    NW Ontario, Canada
    A 2 gallon pressure tank on a well pump would be fine for a sprinkler system that is matched to the GPM of the pump so that it doesn't cycle. Also would work with a CSV.
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Sep 2, 2004
    Retired Systems engineer for defense industry.
    New England
    WH expansion tanks are designed to be installed on the cold water supply and won't work well on the hot side - the bladder dies earlier. Both a well tank and a WH would normally only have cold water feeding them, so, it's likely either should work. A well tank bladder would probably see MUCH more expansion/contraction of the volume of water, and to survive a decent service life, the bladder may be more robust to take the regular large excursions as the pump cycles. A WH, depending on its size, may only need to accommodate a cup or so from expansion, a well tank much more.
  6. Gary Swart

    Gary Swart In the Trades

    Sep 1, 2004
    Yakima WA
    Interesting you found a thermal expansion tank at Lowe's. My Lowe's doesn't even know what they are. That aside, I have had my expansion tank in place for 5 years and it is still just fine.
  7. zl700

    zl700 DIY Senior Member

    Aug 26, 2009
    Western NY
    Unless its on a variable speed constant pressure well system or a jet pump booster system and then 2-gallon well tanks are the norm.
Similar Threads: Gallon Expansion
Forum Title Date
Water Heater Forum, Tanks Looking for a good 2 gallon S/S expansion tank Dec 2, 2012
Water Heater Forum, Tanks Three 75 gallon water heaters tandem Oct 24, 2017
Water Heater Forum, Tanks Three 75 gallon water heaters Oct 22, 2017
Water Heater Forum, Tanks Rewire two 80 gallon off-peak electric hot water heaters? Aug 25, 2017
Water Heater Forum, Tanks 30 gallon hot water tank from 1983 Jun 20, 2017

Share This Page