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Buderus Pressure

JoeBags Member Posts: 5
Hi. My GB142 system has low pressure. When it was first installed, the installer showed me how to increase the pressure should I ever need to, but I've forgotten. I've attached a picture. Thanks for any help!


  • steve_25
    steve_25 Member Posts: 36
    Low Pressure

    I'm having the same problem. It's not always low but the "H7" or "P13" shows up a lot on the control panel.
  • JoeBags
    JoeBags Member Posts: 5
    Error Code

    My understanding is that the H7 is the error code for low pressure. The P is your current pressure. Yours is 13. Mine is 3 - which is so low the system won't even come on.
  • JStar
    JStar Member Posts: 2,752

    You have a leak. You should never have to fill the system after the installation.
  • JoeBags
    JoeBags Member Posts: 5
    edited September 2012

  • CMadatMe
    CMadatMe Member Posts: 3,086
    Never, Never

    Just add water to the system without determining how it found its way out of the system. It did not just disappear.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • Paul48
    Paul48 Member Posts: 4,469

    Signs of leaks in the photo.
  • Mplsavant
    Mplsavant Member Posts: 20
    There should be a spiket

    fill valve on your line. On my GB142 I have a washer hose attached to one spiket with new water connected to the other spiket on the line running into the boiler.....this is how I fill mine whenever I need to....also, I've had mine for 7 years, it will need an occasional fill....
  • JoeBags
    JoeBags Member Posts: 5
    Mplsavant Correct

    Yes. Plumber said my system has an auto-fill valve that got stuck, so it was just a matter of a manual flick of the valve to over-ride. No, no leaks. Heating system not even on, just hot water. Plumber tested for leaks - none. Touch of condensation here and there, but no leaks.

    Plumber said it is completely normal for any condensing boiler system to very gradually lose pressure over time if it has no auto-fill. No way of knowing, but could have been gradually over 2 years in my case.
  • CMadatMe
    CMadatMe Member Posts: 3,086
    Scratch, Scratch

    If the system is a closed system which this is, where does the water go? Does is evaporate into thin air?
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • JStar
    JStar Member Posts: 2,752

    That is bad information. How did he test for leaks?
  • JoeBags
    JoeBags Member Posts: 5
    edited October 2012
    Reply to JStar "Ugh!"

    Here's a quote from the Buderus website:

    The pressure loss in a heating system is caused by

    air bubbles escaping via fittings and (automatic) air

    vents. The oxygen contained in the fresh heating

    water will also escape from the heating water after

    some time and cause a pressure loss.

    Topping up once a year is normal. If it is necessary

    to top up more frequently, there might be a leak in

    the system or a defective expansion vessel. This

    must be remedied as soon as possible.
  • JStar
    JStar Member Posts: 2,752
    edited October 2012

    That makes sense...if you have a leak every year.

    When you install a boiler, bleed the air, and heat the water, you'll release air from the system one time. After that, how does new water enter the system? It shouldn't, unless there is a leak.
  • Zman
    Zman Member Posts: 7,446
    The answer to the question...

    Somewhere in your system you have fill valve/prv and a back flow preventer. It usually connects between the expansion tank and air eliminator. There is a lever that will allow you to manually add water to your system. If adding water to your system becomes a regular event, you have a leak that should be addressed. Adding a gallon or so a year is not such a big deal. Some mod/cons, especially Buderus, leak a little. I would not "throw the baby out with the bathwater". Just add some water and keep an eye on it.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
This discussion has been closed.