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Buderus Logamax GB142 Code 0H - not pulling heat despite demand from thermostat

Vipul
Vipul Member Posts: 3
Hello,

I have a Buderus Logamax GB142.

Now that summer's over in Pacific Northwest, I went to turn on the floor heating and while the water aspect were working fine all summer, there seems to be no action when thermostats demand heat.

I see the display code 0H coming up and the temperature displayed remains constant at the temperature of the system/water inside.

Despite all attempts (stopping the entire system and restarting it), it did not start the boiler. So I tried the "chimney sweep" and it immediately lit the Led "Burner Operation" and boiler started working and heating the water up.

The problem with the chimney sweep button is that
(i) When I exit the chimney sweep mode, the boiler stops heating water. The boiler works as long as it is in the chimney sweep mode
(ii) While it seems to work in the chimney sweep mode, I do notice smell of gas which was not there before. I am concerned that the chimney sweep mode is leaking gas, or I am not using it correctly.

I took a video to explain which I have uploaded on YouTube. https://youtu.be/hvKRsNrskbE

I am looking for guidance on what I should do next. Thank you and happy Saturday.

Comments

  • Big Ed_4
    Big Ed_4 Member Posts: 2,762
    Your getting a OH code ? Did you look it up
    I have enough experience to know , that I dont know it all
  • Vipul
    Vipul Member Posts: 3
    Big Ed_4 said:

    Your getting a OH code ? Did you look it up

    Hi Big Ed_4, OH code means no demand signal received for heat and system in a steady state.
  • Big Ed_4
    Big Ed_4 Member Posts: 2,762
    Check the AM10 control program to see if it was set right .Check to see if the outdoor sensor reads the ODT correctly . Check to see if if its getting a signal from the pump relay , Could also be a bad AM10
    I have enough experience to know , that I dont know it all
  • Vipul
    Vipul Member Posts: 3
    Thanks Big Ed_4. I am so stupid. The setting on AM10 was set to not kick off until the external temperature was below 32 and we were at 46 degrees. So silly of me when I mucked with the settings earlier this year to turn of rating heating.

    Appreciate the pointers