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Designstate Member Posts: 1
Hello All, I have searched and couldn't find any posts regarding this. I have a 10 year old Lagano G115 oil fired burner with 2107 Logamatic control. I checked the system today (which is producing heat fine) and noticed the BLR SENSOR ERROR message and no boiler temp showing on the display. I read the book and it said to check the connections and replace the sensor if necessary. I cannot however find documentation that shows me where this sensor is and where to purchase a new one. I don't want to call in a tech as I can replace pretty much anything. Can someone point me in the direction as to where to buy this and how to check it? Also, what is the harm in the system running without that sensor talking to the Logamatic? Is it just not efficient?

Thank you all so much,



  • Gordan
    Gordan Member Posts: 891
    Kyle, don't take this the wrong way

    You have a decently expensive boiler. If you can't search/reconstruct your way to the answer you're seeking, perhaps you should protect your investment by paying for someone qualified to work on it.
  • Design_state
    Design_state Member Posts: 1
    none taken

    Just an update. I contacted Buderus who agreed that they don't have literature on the part I am seeking. No part numbers and the only place to order would be through a HVAC or repair company. I then contacted an authorized Buderus servicer who said they would sell me the part. I did locate the part in question at the top of the unit and traced back where it plugs into the Logamatic. Should be straight forward enough. I have replaced relays when they have gone bad and was able to diagnose that problem with ease and a 3 dollar part. I was hoping someone would have had some advise other than call a tech. I have rebuilt cars, have a masters degree in industrial design, and am an experienced DIY'er if you can call it that and work as a design engineer. I am not the average home owner. I have had 3 service companies in 6 years and no one has shown me confidence in the Buderus unit. I personally don't trust I would have a tech out that would know what they were doing. Let alone have the part with them. I know it would cost me two service calls all for a part that will take 10 minutes to replace. I am the one that has to tell them to check my anode on my indirect tank in order to not void the warranty. I then have to loan them my multimeter cause they don't carry one. (this has happened with all three) I now just check it myself and note the number on the ticket. If anyone has any advise other than call a tech I would be interested in hearing it.

    Sorry for the rant. I was just hoping for a forum with better support. Thank you,
  • Gordan
    Gordan Member Posts: 891
    Sure they have literature

    They have service literature on the control you're trying to service, which includes the resistance curve for the sensor that would tell you what type of thermistor it is and locate the terminals to which it is wired and trace the leads to the part. If I hadn't been able to find it near the top of google search results I would not have written what I wrote. My default answer is definitely NOT "get a tech" but it seemed like good advice in your case.

    So ok, now you have the part and certainly the replacement of the part is comfortably within your skill set. What advice do you need?
  • Big Ed_4
    Big Ed_4 Member Posts: 1,650

    The boiler sensor is the same sensor used on the an indirect hot water heater that came with the control, If it was not used it might be laying around .. Sometimes the stainless well leaks destroying the boiler sensor if you notice corrosion change the well too...
    I have enough experience to know , that I dont know it all
  • Mike262
    Mike262 Member Posts: 1
    Big Ed....thanks...I have Buderus for almost ten years and the BLR sensor has burned out five times. The technician just keeps throwing in the part and I just don't have confidence in the unit. He never tries to troubleshoot......could it be a stainless well leak and if so is this a relatively easy repair? Thanks....My wife is ready to replace the whole unit......
  • MartinStein
    MartinStein Member Posts: 1
    What is the Buderus PN for the BLR Sensor? I have the G115 with Logamatic R2107 also.
  • Kell70
    Kell70 Member Posts: 1
    edited January 2020
    Hello, not sure if anyone is still reading this thread, but I have a Buderus Logamatic/Logano GA244 -it was installed 2006. I have what looks like a BLR sensor error and I have been trying to find an authorized Buderus rep in my area of Massachusetts. I don't think I can attempt to fix this on my own. This is a gas heating system. I will continue my search, but this came up in my search and I figured I would put it out there. I am located North of Boston. Thanks!
    HVACNUT Member Posts: 3,808
    Buderus: 1-800-283-3787
    They should be able to help.
    Does the boiler have the 2107?
  • Big Ed_4
    Big Ed_4 Member Posts: 1,650
    You have two boiler temperure sensors on your Logamatic The thermistor , of it fails , I would check a leaky boiler well and the second wold be connected to the temperture knob and they can just go . I replaced a few of both
    I have enough experience to know , that I dont know it all
  • mattespo
    mattespo Member Posts: 2
    Where did you end up finding the parts ? I’m having the boiler temp error code also.   
  • mattespo
    mattespo Member Posts: 2
    I have the Logano G115 oil fired 
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