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  1. #1
    Join Date
    Aug 2008
    Posts
    10

    High Efficiency Boilers

    We are looking to upgrade our 43 year old cast iron boiler to a new 90%+ mod/con unit and add an indirect water heater. We've had several quotes and I'd love some expert advise on the brands below OR feel free to give me other brand names. We really want to do this right and have a quality boiler installed. Many thanks!

    Munchkin 80m 92% boiler and Smart 30 indirect water heater.

    NTI 150,000 BTU Boiler & domestic Hot water

    Buderus GB142-30 94.8% eff. boiler with Buderus 32 gal. indirect water heater

    Dunkirk deluxe model #Q90-100 90% boiler and Bradford 40 gal. indirect water heater and Tekmar Model #509 modulating boiler temp. control.

    Munchkin 199M 95% boiler and Amtrol indirect water heater

  2. #2
    Join Date
    Jul 2008
    Location
    Denver, CO
    Posts
    4,229
    Quote Originally Posted by gstone View Post
    We are looking to upgrade our 43 year old cast iron boiler to a new 90%+ mod/con unit and add an indirect water heater. We've had several quotes and I'd love some expert advise on the brands below OR feel free to give me other brand names. We really want to do this right and have a quality boiler installed. Many thanks!

    Munchkin 80m 92% boiler and Smart 30 indirect water heater.

    NTI 150,000 BTU Boiler & domestic Hot water

    Buderus GB142-30 94.8% eff. boiler with Buderus 32 gal. indirect water heater

    Dunkirk deluxe model #Q90-100 90% boiler and Bradford 40 gal. indirect water heater and Tekmar Model #509 modulating boiler temp. control.

    Munchkin 199M 95% boiler and Amtrol indirect water heater
    I think you have made a wise desicion to upgrade to higher efficeny equipment. The indirect water heater is a great idea. You will save enough in heating cost to pay for the equipment in a few years.

    Lets say you are getting 60% effienciy out of your current boiler. Thats .40 out of every dollar you spend to heat you home just wasted. Now bump that up to 90% and do the math. You will be happy you made this decision. Now the water heater. The average water heater fires 7 times a day when not in use. Just to keep stored water hot and ready for use. Now you will be heating cold water only when you need it thats a big saveings right there

  3. #3
    Join Date
    Aug 2008
    Posts
    10
    Thanks. Anyone have any thoughts about indirect water heaters? I'm told that a 30 gal. will provide more than enough hot water but I want to plan on the future too... At some point we'll add a jaccuzzi tub and I want enough water to fill it and then some... Still need some advice on boiler brands too. Looking for longevity/quality.

  4. #4
    Join Date
    Jul 2008
    Location
    Denver, CO
    Posts
    4,229
    Quote Originally Posted by gstone View Post
    Thanks. Anyone have any thoughts about indirect water heaters? I'm told that a 30 gal. will provide more than enough hot water but I want to plan on the future too... At some point we'll add a jaccuzzi tub and I want enough water to fill it and then some... Still need some advice on boiler brands too. Looking for longevity/quality.
    How many fixtures will this tank be feeding?

  5. #5
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,090
    You aren't going to fill a jucuzzi with a 80,000 BTU mod/con boiler on a 30 gal, more like an 80 gal indirect.

    You might want to look at the Weil McLain Ultra mod/con.
    With a 40 gal indirect.(still won't do the jacuzzi) An Ultra 155, and a 60 gal should though.

    Do you have copper baseboard, or cast iron rads.
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  6. #6
    Join Date
    Jul 2000
    Location
    Northern Wisconsin
    Posts
    2,013
    If you have the make and model numbers of the indirects that are being quoted you can go to the manufacturers website and find the information that tells you how many gallons per hour you'll get at what btu/hr boiler and input water temp. This information should get you started on figuring out what size you need in a tank..... then that will tell you what size boiler you'll need.
    Use the biggest hammer you like, pounding a square peg into a round hole does not equal a proper fit.

  7. #7
    Join Date
    Aug 2008
    Posts
    10
    The indirect water heater has 5 sinks and 1 bath on its "load". However it would be extremely rare for more than 1 sink (2 at most) to be used at same time. But... we are just starting our family and kids are on the horizon...

  8. #8
    Join Date
    Aug 2008
    Posts
    10
    We have copper base boards. I was told by several contractors that a 40 gal. indirect would supply us with almost "unlimited" hot water. I'm obviously not super confident in all of the bids hence why I'm on this site. I'd hate to spend all this $ on a high eff. system and 5 years down the road discover that it can't handle the hot water load... The "jacuzzi" we are looking at is basically a 2 person tub w/ jets (its good a size but not a gigantic)

  9. #9
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,090
    A 40 gallon indirect hooked to an 80,000 BTU mod/con should cover teh average family.

    A 40 gal indirect at 90° temp rise, can have a recovery rate of around 120 gallons an hour.
    Thats sounds like a lot. Until you try to fill a jacuzzi in 10 or 20 minutes. If you try to fill a 60 gallon jacuzzi in 10 minutes, you will have over tapped it.

    How many gallons will the jacuzzi hold.
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  10. #10
    Join Date
    Aug 2008
    Posts
    10
    he jacuzzi holds about 60 gal (max). What about those boilers that also make domestic hot water on demand?

  11. #11
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,090
    Find out their GPM and at what temp. You might find they can't fill your jacuzzi in 30 minutes.
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  12. #12
    Join Date
    Dec 2004
    Location
    Grand Rapids, MI
    Posts
    618
    Knight boiler with correctly sized indirect would be a good choice. luck dan

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