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Buderus model 115/21 with a NEW LT300

Pro
Pro Member Posts: 15
Have hooked up but NO DOMESTIC HOT WATER. Help! Have plenty of parts, but I'm missing something.
Pro (homeowner)

Comments

  • Pro
    Pro Member Posts: 15
    Have LOGMATIC controller with a RIELLO 40 burner and a WESTWOOD Ultra 10 filter. Have TIGER LOOP, but not yet installed.
  • Pro
    Pro Member Posts: 15
    Lastly, twin ROTH tanks and a reserve ( 260 gallon )tank). 3 zones, planning a a fourth ( Radiant Heat )
    Canucker
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    What did the installer say? Was domestic hot water enabled?
    steve
  • Pro
    Pro Member Posts: 15
    It was enabled, but no luck. I'm trying to figure it out to see if it's just a glitch or what.
    Thank you
  • HVACNUT
    HVACNUT Member Posts: 5,803
    edited February 2020
    2107 or 2109?
    Is the indirect powered through the Logamatic or a separate relay?
    In the Logamatic, the DHW circ to line volt block Grey 24 and 25. Tank sensor wires to low volt block Grey 1 and 2.
    Is there a faucet displayed on the screen?
    You went through all the prompts?
  • GW
    GW Member Posts: 4,691
    Go to the relay test and make the pump go. That will tell you what’s up. Also when you scroll the big dial can you see the DHW tank temp? Some people can’t deal with the 2107. I dig them a lot
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    gary@wilsonph.com
  • Pro
    Pro Member Posts: 15
    Definitely a 2107.
    Went through all the prompts, but will do again and report.
    Will take input and verify.
    Will use book and set up and report.
    I thank both of you for responding.
  • Pro
    Pro Member Posts: 15
    To HVACNUT,
    Definitely a 2107.
    Powered through the Logamatic.
    Wiring wasn't changed, but appears to be correct.
    There is a faucet (#2) in the icons.
    I went through all the prompts. NO CHANGE.
    To GW,
    How do I test relay?
    GRUNDFOS recirculatory whirrs, get hot, but doesn't push water through.
    The DHW is 55 degrees. That is all.
    Here are the pictures.
    Sorry, I had a medical emergency.
    PRO



  • HVACNUT
    HVACNUT Member Posts: 5,803
    Hope everything is ok.
    Pics didn't come through.
    Seems like the loop is air bound and, or the pump is seized.
  • GW
    GW Member Posts: 4,691
    Pro get well soon. The pump makes noise but doesn’t move heat (water)?. You know how purge the circuit? There’s a specific yet simple process
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    gary@wilsonph.com
  • Pro
    Pro Member Posts: 15
    To HVACNUT,
    Thanks for the well wishes. Will post pics.
    Will bleed system again, but I don't think that is the problem. I've been known to be wrong though.
    To GW, Thank you for your wishes. No, I don't know how to purge system unless bleeding it
    fully is the same. Will attempt today and post with pictures. Perhaps you could give specific instructions to purge, as COLD water is the pits.
    The DHW was on, the Recirculatory pump was on, temp was set to 140 but didn't move past 55, and I have no HOT WATER.
    Thank you,
    PRO
  • HVACNUT
    HVACNUT Member Posts: 5,803
    edited February 2020
    Yes purge and bleed have the same meaning. But to me, you purge a loop, you bleed a radiator. Why? I dunno.

    But yes, post a pic of the system so we can see if you're properly purging, or bleeding, or expelling, or displacing, or even burping.
  • Pro
    Pro Member Posts: 15
    Will DO!Pro
  • Pro
    Pro Member Posts: 15
    I have HOT WATER. The GRUNDFOS recirculatory pump was stuck. I gave it a rap (a couple) and temps started to climb. 6 degrees in 30 minutes. Pictures are enclosed. This is a 76 gallon indirect water heater so I may have to wait awhile.

  • BDR529
    BDR529 Member Posts: 281
    Is that the purge assembly on the vertical pipe? and behind the drip tube on the relief is a fullport ball valve? A purge on the expansion tank? Wonder what the returns look like..

    So, 6 degrees in 30 mins.. Your heat will be off until the domestic is satisfied. Hope the Mrs. is understanding.

    That tank is overkill to say the least.
  • Pro
    Pro Member Posts: 15
    I inherited this...I didn't design it. The back of the Buderus LT300 is plumbed quite natural, although the pictures didn't appear. I can always bypass the operation.
    Pro
  • HVACNUT
    HVACNUT Member Posts: 5,803
    If the Grundfos is a UPS15-58, make sure it's on low speed.
    The sweet spot on the LT300 is 6 GPM at 1 ft head. Even with additional piping and bends, it will flow about 9 GPM.
  • Pro
    Pro Member Posts: 15
    The GRUNFOS was intermittent so I ordered a new one. Mine is a UPS15-58 FRC unit. I was greeted by a DHW ERR message and a whiny pump ( When it worked). I'll put it in Wednesday and let you know. Thanks for the low speed tip.
    Pro
  • Pro
    Pro Member Posts: 15




    I have NO HOT DOMESTIC WATER. Replaced the GRUNDFOS because it was only operating some of the time with a GRUNDFOS UPS15-58 and it works, but NO HOT DOMESTIC WATER. Pictures attached, so what is wrong?
  • HVACNUT
    HVACNUT Member Posts: 5,803
    Did you purge the loop?
    If the circ is running, its gotta be air bound. Or a valve is closed.
  • Pro
    Pro Member Posts: 15
    Purged the loop twice until full water. Will purge, and listen for any tell-tale signs. Will check for valves, but all faucets flow readily. I will check 100% though. Thank you.
  • BDR529
    BDR529 Member Posts: 281
    Is the DHW circ wired the the recirc terminal?
  • BDR529
    BDR529 Member Posts: 281
    Could also have a thermistor and/or burner problem.

    You know, swap the 2107 control out for a standard aqustat and wire accordingly. It would make life easier.

    Will be no change in effcy.
    SuperTech
  • Pro
    Pro Member Posts: 15
    To all, I am back again. The DHW production is GOOD, but I want to be sure I have this plumbed/wired/hooked up correctly. Any suggestions are WELCOME. My health has not been the greatest, but all is fine at the moment .
    Pro
  • HVACNUT
    HVACNUT Member Posts: 5,803
    > @Pro said:
    > To all, I am back again. The DHW production is GOOD, but I want to be sure I have this plumbed/wired/hooked up correctly. Any suggestions are WELCOME. My health has not been the greatest, but all is fine at the moment .
    > Pro

    I don't know if you tried to post pics but they didn't come through if you did.
  • Pro
    Pro Member Posts: 15
    I will post pics later tonight. Thank you.