1. Welcome Hearth.com Guests and Visitors - Please enjoy our forums!
    Hearth.com GOLD Sponsors who help bring the site content to you:
    Hearthstone Soapstone and Cast-Iron stoves( Wood, Gas or Pellet Stoves and Inserts)
    Caluwe - Passion for Fire and Water ( Pellet and Wood Hydronic and Space Heating)

Introduction and expansion tank questions

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by DZL_Damon, Apr 16, 2013.

  1. DZL_Damon

    DZL_Damon Member

    Joined:
    Apr 16, 2013
    Messages:
    177
    Loc:
    Maine
    Hello all,

    I've gathered lots of information thus far from this helpful forum, and thought I'd give a brief introduction of my set up along with a question.

    I just received my new 102kbtu (30kW) Kedel pellet boiler. I am in the process of plumbing it up with a 120 gallon pressurized buffer tank and keeping my old Pensotti oil boiler in parallel. I will have x4 zones including my shop plus a 30 gallon domestic hotwater heater.

    My first question has to do with expansion tanks. My rough calculations indicate I will need about 16 gallons of expansion tank for my system. When I was at the plumbing supply store they told me they had a 14 gallon system, and I was simply going to keep my existing 4.4 gallon tank in place as well. However, the woman behind the desk then suggested a 20 gallon tank that was actually a few bucks cheaper... so 20 gallon it is.

    Upon getting home, I remove the tank from it's box and realize it is actually a well tank called "Water Pro manufactured by Amtrol". It's a WP20 and states on the side it's not designed for operation above 140*F and max temperature is 200*F.

    Should I return this back to the plumbing store and get the 14 gallon unit rated for an expansion tank, or are these common tanks to use for larger hydronic units?

    Thanks for your advise!

    Helpful Sponsor Ads!





  2. arngnick

    arngnick Member

    Joined:
    Feb 15, 2013
    Messages:
    244
    Loc:
    Mansfield, PA
    Return the tank and get a tank designed for heating. Make sure that you check the air presure in the tank set it at your systems design pressure. (I learned that you need to set the pressure the hard way)
  3. ewdudley

    ewdudley Minister of Fire

    Joined:
    Nov 17, 2009
    Messages:
    1,694
    Loc:
    Cayuga County NY
    If it was a lot cheaper you could work around the temperature limitation by locating the tank a fair distance away and using small copper line to insure that the expansion water was cool enough by the time it got to the tank. You could even work in a section of finned tube if it's convenient. If you work it out you'll find the flow rate is very low.

    But if it's just a matter of swapping for the right tank you might as well go ahead and do that.
    BoilerMan likes this.
  4. stee6043

    stee6043 Minister of Fire

    Joined:
    Aug 22, 2008
    Messages:
    2,350
    Loc:
    West Michigan
    Not only should you return it but you should tell the lady behind the desk that she owes you a case of beer for selling something she had no business selling. I wonder how many times she's sold a well tank for use in a heating system....?

    I personally would not risk using a domestic water tank on a heating system even if it was located a significant distance from the heat source. Should that tank ever fail and you need to make some kind of insurance claim you're going to be SOL if you clearly used a tank not designed for that application.
  5. ewdudley

    ewdudley Minister of Fire

    Joined:
    Nov 17, 2009
    Messages:
    1,694
    Loc:
    Cayuga County NY
    Actually the Water Pro is a superior tank. It has stainless steel fittings and is lined with poly, so is immune from corrosion, unlike the cheaper Extrol type tanks designed for less demanding hydronic applications.

    Working pressure is the same. Temperature rating is different, which might be relevant, or perhaps of no concern whatsoever. If deployed in an application that limits working temperature to be within spec, then you're good to go.
    BoilerMan likes this.
  6. BoilerMan

    BoilerMan Minister of Fire

    Joined:
    Apr 16, 2012
    Messages:
    1,579
    Loc:
    Northern Maine
    This is why around here, the plumbing suppliers (FW WEBB, Redlon&Johnson) will NOT sell anything to homeowners. The counter guys/gals are there to fill your order not decide if a certain part is right for a certain application. The well tank vs hydronic tank is an extreme, but it is not the lady's fault, a counterman would know the difference, but homeowners are not exactly well versed in plumbing lingo either.

    TS

  7. I had a friend put me as authorized user on his account at Webb so I could pick up what I need from time to time and get his pricing. You should see the counter guys glare at me when I tell them I want to put it through an account but pay cash! Like I'm personally stealing candy from them.

    In the end it's usually easier to find what I want on the net.
  8. Bob Rohr

    Bob Rohr Minister of Fire

    Joined:
    Jan 9, 2008
    Messages:
    783
    Loc:
    SW Missouri

    I would purchase the correct tank for the application. If you use a 140F tank and it fails, the warranty would be void if you were to return it and indicate how it was used.

    There is a method to install a cool down tank which is common on high temperature solar piping. The intent to to prevent a slug of high temperature fluid from contacting the bladder. Zilmet builds this plain steel, nipple on either end, cool down tank.

    Still, get the correct tank and sleep better.
  9. DZL_Damon

    DZL_Damon Member

    Joined:
    Apr 16, 2013
    Messages:
    177
    Loc:
    Maine
    Thanks for the advise. This was at FW Webb actually, and I told them I needed a thermal expansion tank for my boiler system. There should have been no excuse for giving me the incorrect tank, I was very specific!

    I ended up returning almost everything I bought that day since I discovered pexuniverse.com. I saved about $80 on zone valves, $60 on circ pumps, and about $80 on 1.25" fittings. On top of that, Webb didn't even supply circ pump flange valves which amazed me. They also quoted me $400+ for a Taco VDT circ pump that only costs $180.

    Anyway... enough about being a cheap skate! Thanks for the advice, Now I have some sweating to do.
  10. Bob Rohr

    Bob Rohr Minister of Fire

    Joined:
    Jan 9, 2008
    Messages:
    783
    Loc:
    SW Missouri

    Water under the bridge at this point.

    In Amtrol lingo a Thermal expansion tank for potable DHW use, its called a Therm X trol. The hydronic tank is an Extrol, and the well tanks are Well X trol. All trademarked names.

    There are some cases where Therm X trol tanks are used in heating appications. A combined system, common in Califiornia and parts of Canada used the hot, DHW water via a fan coil to heat the space. So that system needs to be all non ferrous and uses a Therm X trol, coated tank. They are limited to operating temperatures under 140F. State water heater company sold this systems for years under the Apollo name. iIt may still be available.

    There is also an online radiant company, from the New England area, that sells and promotes combined DHW/ heating piping for their radiant packages. Those require Therm X Trol type of tanks.

    So the order taker may have heard Thermal Expansion, and being a well trained Amtrol dealer, just entered a Therm x trol on the order.

    Sounds like you are up and piping, and on your way.

    Attached Files:

  11. DZL_Damon

    DZL_Damon Member

    Joined:
    Apr 16, 2013
    Messages:
    177
    Loc:
    Maine
    Thanks for the explaination of the nomenclature Bob. Very useful for future applications

    What she gave me was a Well-X-Trol, not the nicer Therm-X-Trol. I now have the Extrol ready to be plumbed up. I feel like she should have known better since we were all talking about my project with a Buffer tank. I just grabbed the brown cardboard box she rolled in from out back, and I threw it in the truck. I only discovered it once I got home to see where it would fit!

    As noted, water under the bridge. 'Twas merely a minor hiccup, but perhaps useful info for future installers searching amongst this forum.
  12. ewdudley

    ewdudley Minister of Fire

    Joined:
    Nov 17, 2009
    Messages:
    1,694
    Loc:
    Cayuga County NY
    I'm confused, above it was a Water Pro, now it was a Well-X-Trol. How do you know what she gave you if you don't know which it was?

Share This Page