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Adding electric hot water heater to help tankless

I have installed a new Combi boiler lochinvar noble it works good once the water gets hot but it takes too long. The boiler does have a preheat option but it does make the boiler turn on and off every 30 minutes. I was planning on adding a 40 gallon hot electric hot water tank after the tankless to help it. But I was wondering if there is any other options.


  • Leon82
    Leon82 Member Posts: 684
    edited December 2017
    You may be able to use a storage tank and heat it with the tankless heat exchanger.
    Does the manual show a recirculation setup?

    A full size tank kinda defeats the purpose of a tankless
  • DZoro
    DZoro Member Posts: 1,048
    Use the pre heat option, that is what it is designed for. It will be much more economical than keeping 40 gallons of storage water. I have one in my own home and works great.
    delta T
  • newagedawn
    newagedawn Member Posts: 586
    a 40 gallon storage with a combi???? did you install it right??? pics of the install could shed light on why it takes so long to heat, my first guess is you undersized it for your needs
    "The bitter taste of a poor install lasts far longer than the JOY of the lowest price"
  • bob eck
    bob eck Member Posts: 930
    What do you mean it takes to long to get hot water?
    The Lochinvar Noble delivers hot water right away.
    Go to the furtherest shower and turn it on. Time how long it takes to get hot water. If it takes 30 seconds, 1or 2 minutes this is not the fault of the combi boiler. That is just how far your shower is from the combi boiler. The Noble boiler is designed to maintain 130 degrees in the heat exchanger to produce hot water right away.
    Check with Lochinvar to see how they recommend to install a domestic hot water recirculation pump system with aquastat and timer. Taco and Grundfos offer these systems. No waiting for hot water. No water waisted and sent down the drain just waiting for domestic hot water. There are recirculation systems that use a return line and ones that do not need a return line.
    Does your Noble combi boiler have a mixing valve on the domestic hot water supply?
  • bob eck
    bob eck Member Posts: 930
    Look in the Noble installation book there are drawings on how to install a domestic hot water recirculation system to get domestic hot water to your faucets faster and waist lest water going down the drain waiting for domestic hot water.
    Click on products
    Click on water conservation
    Check out what they have to offer