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Buderus boiler erratic water temps.

I have a Buderus GB142-30 boiler installed in my house for both domestic hot water and radiant heat. The problem that I am having is erratic hot water temps. They vary from warm to scalding hot. There are various sensors on the unit, but I am not sure if that is the problem and/or which one may be faulty. Any ideas?


  • dopey27177
    dopey27177 Member Posts: 872
    To avert the scalding issue you need to install a hot water mixing valve to blend cold water and hot water to a desired water temperature. Do not exceed 120 degrees F as that is near scalding temps.

    I do not know what controls you have on the boiler but to have a constant supply of hot water the aquastat should be set to 180 off and 170 on.

    i am assuming you do not radiant heating.