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Buderus HS 2109

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Dubld
Dubld Member Posts: 7
in Oil Heating

I have an HS 2109 on a G115 Buderus oil fired with indirect DHW tank.

It appears the reostat for adjusting the DHW temperature has been damaged and the DHW is coming out at 160 degrees, too hot for us.

Is there any means of replacing the reostat? Or is this a non-serviceable part of the controller?

Have seen mention of replacing controller with the 2107. Does it do DHW and heat via zone controller?

Freezing in AK

Comments

  • HVACNUT
    HVACNUT Member Posts: 7,329

    What part are you referring to as a reostat? Have you checked the tank sensor?

    Screenshot_20260106_060059_Samsung Notes.jpg

    The 2107 is a nice control but there's not many who can navigate through it. The newer G115 boilers offer the Hydrostat 3250 Plus, or the Beckett Aquasmart. The well would also need to be replaced, and an aquastat installed on the water heater.

    Big Ed_4
  • Big Ed_4
    Big Ed_4 Member Posts: 3,421

    I would check or replace the tank sensor before I chuck the control . Hope this helps

    There was an error rendering this rich post.

  • Dubld
    Dubld Member Posts: 7
    1000005674.jpg
  • Dubld
    Dubld Member Posts: 7

    This is the reostat. The knob on the front of the panel has a dial corresponding to the temperature. It is physically connected to the + pattern seen in pic. Rotates like an old school dimmer switch.

  • HVACNUT
    HVACNUT Member Posts: 7,329

    Is it physically damaged? Has the sensor been tested?

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 11,800

    I don't like the looks of that rheostat.  Wires are askew on the inside of the resistor coil.   Also it does not look like the part is repairable or replaceable.  That control is shot unless you want to store the water in the tank at 160° and use a mixing valve to adjust the water temperature leaving the tank.

    The Americanized boilers from Germany are using the Hydrostat or the Aquasmart controls as @HVACNUT mentioned. That might be the better choice here.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    bjohnhy
  • Dubld
    Dubld Member Posts: 7
    1000005677.jpg
  • Dubld
    Dubld Member Posts: 7

    Thanks Ed and others that have kicked in on this.

    The reostat is definitely damaged and is not functioning properly. An option I was considering, but not quite sure if it will work, is disconnecting the wires from the aquastat at the control and just adding a separate temperature control, thereby bypassing the damaged reostat.

    The aquastat seems to work, it turns the pump on and off, but temp is all or nothing.

    Any ideas on a a temp control mechanism?

    DD

  • Big Ed_4
    Big Ed_4 Member Posts: 3,421

    What tank are you using ? You can bypass with adding a aqua stat to the tank ..

    There was an error rendering this rich post.

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