Arkansas What is this? Help.

Discussion in 'Maintenance and Troubleshooting' started by Mars, Jan 6, 2019.

  1. Mars

    Mars New Member

    Everyone, I am new here. Sorry if this has been posted before. I would search, but I'm really not sure what to look for. Anyway, long story short: I'm replacing my electric water heater and this is what my drain (on the old heater) looks like. The 2 lines are coming from my water furnace. My guess is that some one used the drain as a water supply for the water furnace. Can someone verify this or give me some direction? If this is the case, I'd rather run pex lines to my hot/cold lines. Thanks all and glad to be here.
     

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  2. Mars

    Mars New Member

    *Hello everyone.
     
  3. nc73

    nc73 Member Forum Leader

    looks like a desuperheater hookup. Is this the buffer tank?
     
  4. Mars

    Mars New Member

    NC, sorry for the ignorance, but I'm not sure what a buffer tank is. This is my only tank, if that helps. Here's another pic. The drain came off and as you can see the outside pipe actually extends inward via a copper tube. What do you think?
     

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  5. nc73

    nc73 Member Forum Leader

    The drain is the spigot not the other two. So you have a 1 desuperheater tank setup. Not the best use of a desuperheater. There should only be one pipe going into the water heater, not sure what the other one on the left is. Take a pic of the heat pump unit.
     
  6. nc73

    nc73 Member Forum Leader

    unless the other one is used as a drain? Even so just put it back how you found it when you replace it.
     
  7. Mars

    Mars New Member

    I will get you a pic of the pump. As for putting it back, that's my dilemma, the darn thing is so old it broke. So now I'm trying to find a way to Jerry rig it.
     
  8. nc73

    nc73 Member Forum Leader

    I'd get all new fittings, you don't need the other hose if it's just a drain. You do need the one that goes to the heat pump. A desuperheater makes hot water when the unit is running, that hot water is circulated into the water heater. It supplements your water heater production. Although you should really have 2 water heaters, one as the buffer tank and the other the powered one, called the finishing tank. The buffer would not have power going to it.
     
    Mars likes this.
  9. Mars

    Mars New Member

    Here's where the two lines are coming from. As you can see the white line is at the top and the one that has insulation is the grey line. I didnt realize the 2nd pic didnt load. Ive uploaded it up above. Oh btw NC. Thanks for taking the time to help.
     

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    Last edited: Jan 6, 2019
  10. nc73

    nc73 Member Forum Leader

    No problem. Yeah the only important one is the copper going to the circulation pump. Get a T fitting and you're good.
     
  11. nc73

    nc73 Member Forum Leader

    Also turn that pump off if you're gonna leave the HP running while replacing the water heater.
     
  12. geoxne

    geoxne Active Member Forum Leader

    That is a coaxial or concentric fitting (pipe inside a pipe) that allows the desuperheater loop to pump through the single 3/4 bung at the bottom of the tank. They are rarely used lately because they can clog quickly with sediment from the bottom of the tank. They do have the advantage of being hydraulically separated from the normal flow in the tank. Yours looks homemade. You can try to make one up or repipe the water heater.
     
  13. Mars

    Mars New Member

    Thanks for the replies u 2. Yeah my heat has been off. The wife and kids are cold. Gonna try and wrap this up soon. Thanks again.
     
  14. arkie6

    arkie6 Member Forum Leader

    That is a coaxial drain fitting to connect your geothermal unit desuperheater supply and return lines to the water heater tank. The gap between the inner and outer lines on that fitting is small and prone to plugging up with sediment. Those are rarely used anymore because of this.

    A more common approach is to connect the desuperheater supply line to the water heater drain fitting with a regular "T" and connect the desuperheater return line to the water heater cold water supply line with a "T". To do it this way, you generally need to remove the one-way (in) check valve in the cold water supply dip tube and install a separate check valve in the cold water supply line above the "T" to the desuperheater. This allows water to be pulled up the cold water supply dip tube and sent to the desuperheater for heating. See single-tank diagram below.

    A better more efficient arrangement is to have two hot water tanks; one being a buffer or pre-heat tank heated solely by the desuperheater with no electric power to the tank, and a second finishing tank that is powered to bring the pre-heat tank up to the final desired temperature. See double-tank diagram below.

    Single tank diagram: [​IMG]

    Double tank diagram: [​IMG]
     
  15. arkie6

    arkie6 Member Forum Leader

    If you need to get your heat back up and running quickly, you can just leave the lines to the geothermal unit desuperheater disconnected and turn off or disconnect the power to the desuperheater pump (open a switch, pull a fuse, etc. per owners manual) to keep from burning up the pump. The efficiency gained by the single tank setup is minimal anyway.
     
  16. arkie6

    arkie6 Member Forum Leader

    Another more detailed diagram for the double tank arrangement showing valves and check valves:

    [​IMG]
     
  17. Mars

    Mars New Member

    Thanks arkie, from another arkie!
     

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