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Buderus boiler trouble

I have an oil fired Buderus boiler with a logimatic.  Recently we woke up to a house that was only 45 degrees, We called our present service co. and they came out and told me the boiler thought the outside temp was 105 degreesF. A sensor was evidently not working and the boiler wouldn't send heat because it didn't think we needed it. The outside temp was about 25  degreesF, This first person told me he would have to set the boiler to Manual to override the sensor and he didn't have a sensor and didn't know what one would cost.

We had heat the rest of the day, The next day we all left for 5 days. I made sure all the thermostats were set to 65.  When we came home our house was 80 degreesF, even though the thermostats were all set to 65 and the water temp was 175.  I called the co, again and a tech, who came out, told me that the temp on the boiler was not turned  down so the boiler was just running really hot and ignoring the thermostats, So we were super heating our house and water for 5 days when no one was here.

When I questioned the company they maintained that the first person had turned down the temp. I was never told overheating may happen. I was then told that if the thermostats were set low there was no way the boiler would heat the house to 80.  This was a direct contradiction to what tech #2 told me when he found the temp was set too high.  The office says the boiler must have another problem unrelated to the sensor issue.

I don't know what to think and if this company comes out again they will surely find some problem, real or fabricated, that will prove they are right. It was not their fault the boiler overheated our house and water.

Can someone comment on this scenario- should I just run away from this company and have someone else come to service it and see if they find a problem?


  • R Mannino
    R Mannino Member Posts: 440
    Can You

    post some photos showing the detail of your system? How long have you had the system? It sounds like the outdoor sensor could be bad or maybe just an adjustment to the Logamatic. The house shouldn't overheat unless the main zone is on constant circulation while on manual.
  • alonzoquixano
    alonzoquixano Member Posts: 3
    buderus boiler trouble

    I can post more detailed pictures a little later but I have attached a

    stock photo of what the system looks like.  The system is 5 years old. 

    The outdoor temperature sensor was the problem.  It was not replaced on

    the first visit, the boiler was just set to manual to bypass the

    sensor.  There is a question of if the boiler temp was turned down. It

    was only the main part of the house and the water heater that was


    If it was set to manual would the boiler override the thermostats and overheat the house and water?

    Sorry I did not get back to you last night, I hope we can still continue this conversation.

  • R Mannino
    R Mannino Member Posts: 440
    When The Logamatic

    is set to manual it should only affect a zone on constant circulation. It can't over ride the thermostats. Your supposed to set the aquastat dial to 140 degrees when using the manual over ride. The instruction manual also states overheating may occur when using the manual over ride setting.
  • alonzoquixano
    alonzoquixano Member Posts: 3
    why overheated?

    Thanks for the response.

    If the manual override was set, no matter what the temperature of the boiler, it would not override the thermostats? One heating zone and the hot water were overheated. Could there be another problem with the boiler unrelated to the sensor and manual setting?

    This has never happened before the setting was changed to manual.
  • Ironman
    Ironman Member Posts: 7,379
    Multiple Zones?

    Do you have multiple zones? If so, you may be getting ghost flow in one or more zone. It will become more pronounced as the water gets hotter. It can be caused by a flow check not closing tightly or by the piping arrangement.

    As R mentioned, if the control is setup for constant circulation, that would also do it.

    Some pics of the near boiler piping and circs, or zone valves are needed. A generic pic of the boiler doesn't tell us about your particular system's piping and controls.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
This discussion has been closed.