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  1. #1
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    Sep 2007
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    Default Cutting bolier out of hot water loop

    I am installing a new hot water heater in a new location. The old configuration tied into the furnace (oil fired, hot water baseboard). I would like to eliminate that loop but I am not sure what to do with the pipes that lead off to the boiler. Should I cut them close to the furnace (I would like to)? Should I cap the ends? My feeling is I should cut the pipes as close to the furnace as possible and then let them stay open. My concern is any water left in the loop will boil and build up pressure in the lines.

    Any help is greatly appreciated.

  2. #2
    Join Date
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    Default Re: Cutting bolier out of hot water loop

    Quote Originally Posted by waltdeckhouse View Post
    I am installing a new hot water heater in a new location. The old configuration tied into the furnace (oil fired, hot water baseboard). I would like to eliminate that loop but I am not sure what to do with the pipes that lead off to the boiler. Should I cut them close to the furnace (I would like to)? Should I cap the ends? My feeling is I should cut the pipes as close to the furnace as possible and then let them stay open. My concern is any water left in the loop will boil and build up pressure in the lines.

    Any help is greatly appreciated.
    I'm not sure of what your trying to do. A furnace is used for warm air heating. There would be no pipes connected to it. Do you have a boiler with a indirect water heater or are you making your hot water with a lank less coil?

    John

  3. #3
    Join Date
    Feb 2008
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    175

    Default Re: Cutting bolier out of hot water loop

    Walt:


    Like John, I am also having problems understanding your post; since you have been around for some time & I have answered some of your previous posts, I am quite sure you have a BOILER, and not a FURNACE----it's important to use the proper terms to avoid confusion; if you can post a diagram or photo of what you're trying to do, things would be clearer for us; if I read your post correctly, you want to cut some type of HW heater, such as an indirect HW heater out its loop, seal the piping to this loop near the boiler, & then install a separate gas-fired or oil-fired, or electric HW heater----yes????????

    If such is the case, yes, you would have to seal the near-boiler pipes, be they cast iron, steel, or copper with the proper soldering or leak-proof compression fittings so the boiler can run properly. Please post back to clarify.
    Last edited by Dobbs; 03-07-2012 at 12:57 PM.

  4. #4
    Join Date
    Sep 2007
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    177

    Default Re: Cutting bolier out of hot water loop

    Sorry for the confusion. Our house is heated by a oil fired, hot water baseboard system. something like this:

    http://www.grainger.com/Grainger/HYD...ipment-_-6E773

    It has the additional capability of heating potable water to take load off of the electric hot water heater. I want to eliminate that loop. I am installing a new electric hot water heater that is in a different location.

    The existing potable hot water loop starts as the cold water coming into the coil on the boiler. The loop then goes through the boiler and off to the existing hot water heater which in turn feeds the house. This is all done in 3/4" copper tubing. I want to eliminate that loop....but am not sure what to do with the copper lines right at the boiler. As there is no water flowing through those pipes should I cap the lines....or just leave them open?

    -Walt

  5. #5
    Join Date
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    Default Re: Cutting bolier out of hot water loop

    Quote Originally Posted by waltdeckhouse View Post
    Sorry for the confusion. Our house is heated by a oil fired, hot water baseboard system. something like this:

    http://www.grainger.com/Grainger/HYD...ipment-_-6E773

    It has the additional capability of heating potable water to take load off of the electric hot water heater. I want to eliminate that loop. I am installing a new electric hot water heater that is in a different location.

    The existing potable hot water loop starts as the cold water coming into the coil on the boiler. The loop then goes through the boiler and off to the existing hot water heater which in turn feeds the house. This is all done in 3/4" copper tubing. I want to eliminate that loop....but am not sure what to do with the copper lines right at the boiler. As there is no water flowing through those pipes should I cap the lines....or just leave them open?

    -Walt
    If I'm reading this right the way it's piped is the cold water first feeds the coil, exits the coil and feeds into the existing heater. From the heater it feeds the hot water lines to the home. If your removing the existing heater then cap the line feeding the coil and the hot line exiting the heater that feed the home. All the piping between the coil and the existing heater can then be removed. There is no need to cap the lines at the coil.

    John

  6. #6
    Join Date
    Feb 2008
    Posts
    175

    Default Re: Cutting bolier out of hot water loop

    Walt:

    This is a good time to think of getting some intervention from a heating pro, or your present oil dealer/service person----that is , if it's not too late & you've already purchased the new elec HW heater unit; there are several issues here that should be addressed so that your final installation gives you a good hot water supply without higher monthly costs.

    1) Whoever originally purchased the boiler, made the mistake of buying a model that has what's known as a tankless coil inside for the hot tap water (domestic hot water, DHW); these internal coils hold about a gallon of HW & are completely inadequate for the DHW needs of a home; seeing this, someone tried to compensate for the original error by adding a holding tank (presumably) which also turned out to be inadequate for DHW supply; along comes the present owner who buys an electric HWH, which will cost him tons of $$$ to operate because elec is the most expensive way to heat DHW, in addition, we have no idea if the elec hot water heater is sized properly to supply adequate DHW.

    2) Since you still have the tankless coil inside the boiler (that red coil thing to the right of the Hydrotherm boiler in the site you posted) that means you still have what's known as a triple aquastat (which is the main boiler control center) on the boiler; this means that every time the DHW temperature in the tankless coil drops below 140 degrees, the aquastat will cause the boiler to fire up to keep the DHW in the indirect coil at 140 degrees; this goes on 24/7 for 360 days/year, burning lots & lots of oil---the remedy is to have a heating tech over to do the complete install & as part of it, to replace the aquastat ($200-$300) with a non-triple aquastat that won't fire the boiler every 10-15 minutes.

    I'm not trying to be sarcastic, but the best way for someone who already has a hot water boiler to obtain a continuous, economical supply of DHW (since you already have a hot water boiler) is to install a 40 gallon INDIRECT HOT WATER HEATER -------the IHWH is simply a heat exchanger that is run via a zone valve or zone circ to use the circulating HW already available in the boiler to heat the 40 gal DHW sitting in the IHWH----simple?? economical?? endless HW?? yes, yes, yes; a unit that lasts for 20 years without breaking down?? YES!

    Check out IHWHs by Triangle Tube Phase 3, HTP Superstor, Weil-McLain G0ld Plus, TFI Everhot or Veissmann---upfront cost for unit & installation is approx $2k, but you'll save tons of money in the long run.

    Hope it's not too late. Get a heating tech in there Walt.


    http://web.extension.uiuc.edu/disast.../waterhtr.html
    http://hotwaterheatersguide.blogspot.com/
    http://www.aceee.org/consumerguide/waterheating.htm
    Last edited by Dobbs; 03-08-2012 at 11:35 PM.

  7. #7
    Join Date
    Sep 2007
    Posts
    177

    Default Re: Cutting bolier out of hot water loop

    John,

    Thanks for the info. Your response was what I thought....but it is good to hear it from an expert. Thank you again.

    -Walt

  8. #8
    Join Date
    Nov 2011
    Posts
    51

    Default Re: Cutting bolier out of hot water loop

    Walt, many times myself and others have explained the whole indirect hot water heater concept. It's the best option. I would certainly take Dobb's advice.

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