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  1. #1
    Join Date
    Jul 2006
    Location
    Cedarville, Ohio
    Posts
    4

    Hot water hook-up for geo-thermal install

    I am in the process of having a Waterfurnace EO60 5 ton installed in our new house. I had previously read on this forum that it is a good idea to have a second water tank (without electric) connected tothe desuperheater for additional water storage capacity. Any comments as to feasability of this setup and specifics, ie; tank size, plumbing configuration, etc, would be appreciated. Also, any other tips or suggestions on installation or setup are welcomed. Tks John

  2. #2
    Join Date
    Feb 2006
    Posts
    91
    We have a system which doesn't have an extra buffer tank and it works well. The tank is gas heated and the gas consumption goes down to near zero in winter. However, we're only two and don't use huge amounts of hot water. The best configuration is to use an unconnected electric tank and connect the cold water input to this first unheated tank. The de-superheater heat exchanger then goes into the bottom of this tank. Connect the output (top) of the buffer tank to the cold water inlet of your normal (heated) tank. As you take water out of your regular tank, the pre-heated water from the buffer tank will enter the bottom of your normal tank. Depending how much water you use and how cold a climate you live in, you could save over 50% in your hot water costs and soon repay the additional cost of the buffer tank. In our case, there wasn't space to install a buffer so we just put the desuperheater loop into the bottom of the regular (gas) tank and it works well for us.

    Hope this helps,

    Paul.

    p.s. gas consumption in our system also goes down during air conditioning season too

  3. #3
    Join Date
    Apr 2005
    Location
    NE PA
    Posts
    698
    All of the units I install use a second 50 gallon electric HW heater. The electric is not connected. It is connected to the cold water line in series with the main HW heater. The desuperheater loop should draw out of the bottom, where the drain valve is connected, and return to a "T" in the cold water inlet.

    Having a buffer tank is a much better solution, since trying to use the normal HW heater, especially a gas model, may not have enough delta T to work well. With the buffer tank you will heat preheated water. Any BTU's and temp rise are heating that the main tank does not need to do.

    paul

  4. #4
    Join Date
    Jan 2007
    Posts
    115
    I'm surprised there's any value to installing one w/o the second tank. In fact, I'd have thought it mildy bad. I'm sure the second tank will pay for itself, and rather quickly so it seems a no brainer to me..

    I'm using an E60 w/a 75 gallon has, not hooked up, feeding a 50 gallon gas, hooked up, feeding another 50 gallon gas, hooked up. I'm fairly confident I can't run out of hot water, and I've certainly tried..

  5. #5
    Join Date
    Jul 2006
    Location
    Cedarville, Ohio
    Posts
    4

    Smile finally, construction is about complete

    After many months, we are finally about ready to fire up the geo-thermal and hook-up the hot water and aux storage tank. Thought I would bump my original post to see if there might be any new idas or suggestions for hooking up the unwired second hot water storage tank. Any suggestions are welcomed. Tks John

  6. #6
    Join Date
    Feb 2008
    Location
    Montreal, Qc, Canada
    Posts
    5

    Hmm

    Just moved in to our new house. The Waterfurnace Premier geothemal pump is running fine to keep the house toasty in the cold Canadian winter... the desuperheater is causing me problems however. My installation is like this:



    - I get hot to warm water at the cold water faucet for a few seconds when turned on ( cold water supply comes from "T" above "cold water in" .
    - I get warm water from the hot water faucet at best and cold when the furnace blower is running. (feels like the water is coming directly from the preheat tank) - household hot water is supplied from the: "hot water out" line .
    - checked the pipes and all is like the diagram.
    - turned off the dwh pump and closed the valves to the preheat tank and the problem is solved: cold water to cold faucet and hot (very hot) to hot water faucet ...

    I'm hoping to have a few clues before calling my installer. Any help will be appreciated !!!
    Last edited by frankspinz; 02-13-2008 at 04:41 PM. Reason: Added some info re. water lines

  7. #7
    Join Date
    Feb 2006
    Posts
    91
    .
    Last edited by pyropaul; 02-13-2008 at 05:04 PM. Reason: saw the error in what I'd written

  8. #8
    Join Date
    Apr 2005
    Location
    NE PA
    Posts
    698
    I have done a number of these, and the only difference is that we pull the cold from the bottom of the tank to the HP and return to the cold inlet of the tank. Reverse flow from what you show.

    What you describe seems almost impossible. Is the main HW tank powered up ? It should be. You are basically feeding warm pre-heated water into your HW heater to reduce the work that it does. No way should the HOT water temp be any different with or w/o the desuperhreater running. The main tank should bring it up to nominal hot temp. As far as warm water from the cold tap, again there should be no reverse flow from the preheat tank line to the cold water. Something is screwed up in the piping somewhere.

    paul

  9. #9
    Join Date
    Feb 2008
    Location
    Montreal, Qc, Canada
    Posts
    5
    I'm thinking maybe the plumber reversed the pipe connections at the HW tank or the preheat tank. There are no markings on the water tanks I can use to verify which pipe should be plugged in where !?

    Model: http://www.giantinc.com/english/prod...c-standard.htm

    I've looked at the documentation and the only way I've seen to differentiate the hot water outlet from the cold water inlet is that the outlet should be on the same side as the drain valve .

  10. #10
    Join Date
    Apr 2005
    Location
    NE PA
    Posts
    698
    Facing the tank (heating elements directly in from of you), normally then cold is to the right, hot to the left. It should have an H and C in the metal near the fittings.

    paul

  11. #11
    Join Date
    Feb 2008
    Location
    Montreal, Qc, Canada
    Posts
    5

    Smile

    Quote Originally Posted by tecman View Post
    Facing the tank (heating elements directly in from of you), normally then cold is to the right, hot to the left. It should have an H and C in the metal near the fittings.

    paul
    Thanks, if that is the case the plumber inverted the preheat tank hook-up. I'll have him reverse the connections in the hopes it solves this issue for me ! I'll post the outcome ...

  12. #12
    Join Date
    Dec 2007
    Location
    oregon
    Posts
    885
    Quote Originally Posted by pyropaul View Post
    We have a system which doesn't have an extra buffer tank and it works well. The tank is gas heated and the gas consumption goes down to near zero in winter. However, we're only two and don't use huge amounts of hot water. The best configuration is to use an unconnected electric tank and connect the cold water input to this first unheated tank. The de-superheater heat exchanger then goes into the bottom of this tank. Connect the output (top) of the buffer tank to the cold water inlet of your normal (heated) tank. As you take water out of your regular tank, the pre-heated water from the buffer tank will enter the bottom of your normal tank. Depending how much water you use and how cold a climate you live in, you could save over 50% in your hot water costs and soon repay the additional cost of the buffer tank. In our case, there wasn't space to install a buffer so we just put the desuperheater loop into the bottom of the regular (gas) tank and it works well for us.

    Hope this helps,

    Paul.

    p.s. gas consumption in our system also goes down during air conditioning season too
    That is not is not a recommended install practice by waterfurnace. The reason is IF the burner lit up,the intake of water from the dip tube will be heated from the burner and possibly turn off the desuperheater pump. When the pump limit sensor sees 120 degrees fahrenheit, it will turn off the pump. Look at the installation instructions. Fossil fueled single tank systems are not recommended.
    Genius = The guy who can do anything...except make a living!

  13. #13
    Join Date
    Dec 2007
    Location
    oregon
    Posts
    885
    Quote Originally Posted by frankspinz View Post
    Just moved in to our new house. The Waterfurnace Premier geothemal pump is running fine to keep the house toasty in the cold Canadian winter... the desuperheater is causing me problems however. My installation is like this:



    - I get hot to warm water at the cold water faucet for a few seconds when turned on ( cold water supply comes from "T" above "cold water in" .
    - I get warm water from the hot water faucet at best and cold when the furnace blower is running. (feels like the water is coming directly from the preheat tank) - household hot water is supplied from the: "hot water out" line .
    - checked the pipes and all is like the diagram.
    - turned off the dwh pump and closed the valves to the preheat tank and the problem is solved: cold water to cold faucet and hot (very hot) to hot water faucet ...

    I'm hoping to have a few clues before calling my installer. Any help will be appreciated !!!
    How old is your unit? There were some units about 6-7 years ago that went out with the DHW IN and DHW out stickers put on backwards. This was on the premier units.
    Genius = The guy who can do anything...except make a living!

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