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Buderus Logan 2107 error meassage

WalshlawWalshlaw Member Posts: 10
I just installed Buderus Boiler G 215 -3 with Riello Oil burner and logamatic 2107 control. Ran fine for 8 days on manual at startup. Now will not fire - error message DHW sensr - but the Indirect (Trangle Tube Phase lll) runs off separate aquastat.  The burner test/manual override does not work either. I turned power  off etc rebooted - nothing. Any advice would be appreciated or should I just install Honeywell aquastat ? 


  • IronmanIronman Member Posts: 5,740
    edited November 2010

    You have to use the sensor that came with the 2107, not the TT aquastat. Just remove the aquastat and insert the sensor all the down into the well. Connect it to the "FW" terminals on the 2107.

    I'll post tomorrow morning on how to reset the 2107. I'm tired right now and would probably mess it up.
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • WalshlawWalshlaw Member Posts: 10
    Logamatic 2107

    I used the buderus supplied chrome well and sensor bundle supplied. TT has separate aquastat. see photo attached. Thanks for your response and happy Thanksgiving weekend..
  • IronmanIronman Member Posts: 5,740
    edited November 2010
    2107 Sensor

    I was not referring to the sensor bundle that goes into the boiler. There is another sensor that came with the 2107 for DHW. Disconnect and remove the aquastat that came on the TT indirect and install the Buderus sensor in the temp. well of the indirect. Once you unscrew the old aquastat, you will see it has a long probe that's inserted deep into the indirect tank. That's where the Buderus sensor goes. Then connect the sensor to the "FW" terminals on the 2107. You can spice the sensor leads with 18 gauge thermostat wire if they're not long enough to reach back to the 2107.

    Also, your pic is of a relay, not an aquastat. The TT's aquastat is the dial on top of it.

    Please post some pics of your near boiler piping, pumps and controls so that I can see what type of setup you have.

    I'll get back later this evening.
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • WalshlawWalshlaw Member Posts: 10
    Buderus Logamatic 2107

    I installed temporary Aquastat to get through the Thanksgiving weekend - getting chilly after 2 days 32 degrees tonight. Pls find photos attached. Thanks again for your advice.
  • IronmanIronman Member Posts: 5,740
    2107 service manual

    Do  you have the manual for the 2107?
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • WalshlawWalshlaw Member Posts: 10
    Buderus 2107 Error Message

    Yes I have service and operating manual.
  • IronmanIronman Member Posts: 5,740
    2107 wiring

    The 2107 is a sophisticated control, but it's not hard to install or setup if you carefully follow the manual. This is assuming you have a fundamental understanding of hydronics and their controls.

    If you could please answer two questions, that would help me to know where to begin:

    1. Are you a pro or diy'er?

    2. Are your controls wired according  the manual?  I'm referring particularly to page 48 that shows the wiring for a Taco pump panel SR504 like you have.

     I realize that you have an aquastat on the indirect. That must be replaced with the Buderus tank sensor.

    The Riello should be wired according to page 45.

    Your low water cut off should have its normally closed contacts connected to terminals # 17 and 18 (orange connector) on the 2107 - remove the jumper from 17 and 18.

    Your indirect pump must be wired to terminals 24 and 25 (gray) on the 2107.

    The reason for the error message is that your tank sensor is not connected, but that is not what's holding the 2107 off. Have you checked the 10amp fuse on the front of the 2107? The black cover unscrews to access it. If it's blown, your circs. are drawing too much amperage and need an isolation relay.

    The high limit could also be tripped under the black nut on the front left. If so, what caused it?

    Please let me know where you're at after checking the above items.
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • WalshlawWalshlaw Member Posts: 10
    Buderus Logamatic 2107

    I am a DIY - but I do not touch electric. I will bring in my electrician and review your list with him - thanks.
  • meplumbermeplumber Member Posts: 678
    You have to turn off DHW in the program.

    You need to go into the program setup.  The procedure is in the manual.  You will need a paper clip to get to the button.

    Scroll to DHW and turn it off.  It will stop looking for the DHW tank and the error message will go away.

    What is holding off the heat is that the control is in DHW priority.  It will not send power to the 63 plug until the call for hot water is met.  If they have taken the 63 plug to the ZC terminals on a circulator relay pack then you have no heat.

    Is the DHW circ wired off the circ pack or 24/25 in the logamatic? 

    It should still fire in the manual position with the knob turned up.

    There seems to be a piece of info that we are missing.
  • IronmanIronman Member Posts: 5,740
    Turning Off DHW

    If you turn off the DHW, you'll create another problem: namely, that the 2107 will not know when there's a DHW call and it will  keep the loop temp in reset and thus not heat the indirect sufficiently or at all during WWSD.

    The tank sensor must be used when there's an indirect with the 2107.


    You need more than an electrician. A competent one may be able to get the wires to the right terminals, but he won't have a clue about what the control should do or how to set it up. The same goes for your "run of the mill" HVAC tech.

    You need someone who is trained and experienced on the 2107. This is a wonderful control that should save you 30% or more if it's setup correctly. It will be well worth the money for you to find a qualified tech who can handle this. I would recommend that you call Buderus and ask them for the name of contractor in your area who is trained and experienced with the 2107. You can also check the "Find a Contractor" tab above.

    Also, that Riello needs to be set up with a combustion analyzer by a trained tech. If you find someone who can do the 2107, chances are they can do this too.

    If you'll post your city/state, maybe someone here on the wall could give help or a recommendation.
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • WalshlawWalshlaw Member Posts: 10
    Buderus 2107

    Good advice - and appreciated. Location is Water Mill NY 11976. If anyone knows a good 2107 Tech please let me know . Thanks.
  • Matthew GrallertMatthew Grallert Member Posts: 109
    2107 is confused

    Your 2107 is confused.  It thinks it's in charge of making domestic hot water and it's not, you've got a separate aquastat and switching relay doing the hot water.  That's OK, not great but OK.  You need to enter NO when prompted regarding domestic hot water and the error mess will go way.  You will lose some nice features though.  What you should do is re control the Hot water with the 2107s probe and get rid of that Honeywell switching relay.


  • WalshlawWalshlaw Member Posts: 10
    Buderus Logamatic 2107 Error Message

    Thanks Matthew - Buderus control will be re installed asap.
  • meplumbermeplumber Member Posts: 678
    Ironman is right. To a point

    When you try and run the DHW off anything other than the 2107 you lose the ability of the boiler to go to high limit on a call for DHW.

    Sorry I had a brain fart.

    It can be done if you are using high temp only, but then why use the 2107 if you aren't using the outdoor reset.
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