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Help on chosing a Indirect hot wanter tank for Lochinvar WHN110

WH Member Posts: 4
I am converting from oil to gas heating this winter. Three contractors quoted me the same boiler Lochinvar WHN110, however, each give me different indirect water tank model: (1) Squire SIT040 (2) Squire SIT050 (3) Super Stor Ultra SSU-45. Which indirect water tank should I chose?

Squire indirect water tank is made by Lochinvar, will they work better with the Lochinvar boiler? According to Lochinvar website <a href="http://www.lochinvar.com/products/default.aspx?lineid=50&type=productline#">Tank Sensor Included for use with KNIGHT Heating Boiler.  </a>However, They are $200-$400 more than SSU-45 depending on the size (SIT040 $200 more, SIT050 $400 more based on the online price search I did). Does it worth the extra money to go with the Squire indirect water tank or the SSU-45 is just fine since it also limited life time warranty?

Also, my house is 2600sqft (including 600 sqft basement) with 4 people live in. What size should I chose for the water tank? 40gallon(SIT040), 45 gallon(SSU-45) or 50 gallon(SIT050)?

One last question, should I consider upgrading to WHN155 in case I need to do addition to the house in the future? If I go with WHN155 w/o doing addition in the future, will this cause lower efficiency for the system and cause short cycle as I read in the discussion here.

Thank you for your help. 


  • Henry
    Henry Member Posts: 996

    Your heating load in Boston is less than our North of you. It should be around 60,000 BTU in the worst of cold there. So that gives you in the owrst cold 50,000 of hot water. I would go with the HTP. This is what I use on samll apartment blocks and big money homes with the tropical shower head and multiple body jets. We have never replaced a HTP indirect. I have one SSU-80 in a 20 unit bachelor that has not run out of hot water. S/S does have its advantages for long term. We are replacing a commercial 100 gal 199,000 BTU condensing boiler next week after only 5.5 years! It perforated!
  • SWEI
    SWEI Member Posts: 7,356
    Did either contractor provide a heat loss calc?

    Do not sign a contract until you know that the boiler is properly sized.  A smaller boiler with a larger indirect might be in your future.
  • WH
    WH Member Posts: 4

    I assume they did. All the quotes I got didn't include them in the paper. I also got quoted on Buderus GB142-30 and Burnam Alpine 105. They have about 100-110KBTU.  So I think the size is about right. (My friend has a 2500 sqft multi-level house and is using a GB142-30).

  • WH
    WH Member Posts: 4
    Re: Capacity

    Thanks for the recommendation. Looks like SSU-45 is a popular choice here. What is the brand of the condensing boiler you are going to replace only after 5.5 years. I hope it is not Lochinvar, which I selected over Buderus because of its stainless-steel heat exchanger vs. the Aluminum heat exchanger. 
  • SWEI
    SWEI Member Posts: 7,356

    Don't assume.  Ask for the numbers before you commit.
This discussion has been closed.