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Budurus GB142 Question

Dave_144
Dave_144 Member Posts: 28
I've done a few searches but can't seem to find out if this boiler uses any water during normal operation?

The reason I ask is we've been getting the H7 low pressure error and have to lift the lever on the feed valve (Watts 1156F) to bring the pressure back up, so that's due for a cleaning or replacement. System loses about 2 psi over a 2-3 week period. Since water is only being fed in manually now, I'm wondering if the use is normal or if it may be an indication of a slow leak somewhere?

Thanks for any input.

Comments

  • Zman
    Zman Member Posts: 6,992
    edited March 2017
    You should not be using water. It sounds like you have a slight leak.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • GW
    GW Member Posts: 4,304
    Heating systems are like car tires, pressure will eventually dissipate. In your case it's possible you have a leak.

    Try popping the cover off the boiler and look for any signs of water or water staining.

    The earlier GBs have less than ideal pipe connections under the boiler, take a look rhere

    If you can't locate a leak in the entire system and you're gonna lose sleep you may want to have someone pressure test the boiler and then the system.
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • Dave_144
    Dave_144 Member Posts: 28
    Thanks for the replies. I suspect it's been happening for a while and the feed valve was compensating until it went south.

    It's a 4 zone system with a indirect DHW tank. Basement is baseboard heat and the other 3 floors are air handlers with hot water coils. I checked all the coils for leaks and the pex connectors on both ends of each run but couldn't see anything wet. The only thing I couldn't check is where the pex connects to the basement baseboards as it's in the wall and the coil inside the hot water tank.

    Gary, you're spot on in terms of the connections under the boiler being a weak point as they look rusted and have been "wet" at some point in the past but are completely dry now. As far as losing sleep, I'm OK with changing out the feed valve which will remedy the low pressure error and leaving it at that. I just remember reading that introducing fresh water, which has a higher oxygen content, can cause corrosion over time. That was my only concern, but not sure how big of a factor it is?
  • GW
    GW Member Posts: 4,304
    edited March 2017
    My opinion, 2 psi every 2 or 3 weeks isn't lots of water. But you're right, probably best to find the leak. What pressure do you raise to? Maybe jack it to 20 and see how long that lasts
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • Dave_144
    Dave_144 Member Posts: 28
    I go to 16 psi and in a few weeks it's down to 14.

    I thought about going higher as you suggest, thinking maybe it would make the leak more obvious but didn't want to cause any unintended issues. Manual says max pressure is 29.

    If it weren't heating season I think could use the shutoffs to isolate the zones and track down which one is the culprit.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 10,317
    Do you have any indication that the relief valve has been leaking? It's possible the expansion tank is on it's way out. If that is what is happening the relief valve would loose water when the pressure builds up. Then the defective feed valve can't replace the water causing low pressure.
  • Dave_144
    Dave_144 Member Posts: 28
    Thanks for the replies. I did a visual inspection and everything looked dry including the relief valve. Did consider the expansion tank as a possibility, but the system pressure doesn't increase all that much when it's hot vs cooler so I suspect the tank is functioning ok?

    In looking at the boiler itself, there does seem to be one or two areas that appear to have leaked in the past but all look dry now.
  • GW
    GW Member Posts: 4,304
    Right Dave of the pressure stays within a few psi your expansion tank is good, presuming the pressure readings are accurate. So you're no longer losing pressure? That's an odd one for sure .
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • Dave_144
    Dave_144 Member Posts: 28
    Thanks Gary. Luckily the system has an analogue gauge which shows both pressure and temp, as well as the digital display on the boiler. The boiler reads 1 PSI lower than the analog, so they're pretty close.

    On 3/2 I set the pressure to 17 PSI and the system temp was 90F (which I suspect is its "resting" temp as its usually that when I look). I checked it again on 3/9 and it was 16 PSI at 90F. So it does appear it's losing about a pound a week still. I'm going to just watch it for a while and not add to see what it does.
  • Dave_144
    Dave_144 Member Posts: 28
    So two weeks ago I set the pressure to 17 PSI and the system temp was 120F. Checked it again today, and the pressure was a little over 15 PSI and the temp was 130F. So it does seem to be leaking slowly.

    When the temp gets warmer and there's no need for heat, would it be OK to manually turn the shutoffs at the start and return of each zone and just leave the DHW open to see if that isolates the leak? Theres a Taco 404 zone control and I could disable that in case one of the thermostats gets turned on accidentally.
  • GW
    GW Member Posts: 4,304
    Yes you can do that, turn your thermostats down in case you get a cold evening

    Did you pop off the cover of the boiler and look for any staining? Yes the leak seems very small
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • CMadatMe
    CMadatMe Member Posts: 3,085
    edited March 2017
    Ummm. A little hint,,,, expansion tank...

    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • Dave_144
    Dave_144 Member Posts: 28
    There were a few places that looked like they had been possibly leaking in the past but were dry when I checked. Does the system need to be full hot when checking?






  • JharrisSeattle
    JharrisSeattle Member Posts: 26
    That air vent needs to be rebuilt. Ive seen many gb air vent float seals that fail over time weeping small amounts of water and drying up. Buderus sells a rebuild kit for these. Check water quality in the system at the same time, it has likely gone south.
  • Dave_144
    Dave_144 Member Posts: 28
    edited March 2017
    Thanks Jharris. I did a quick search and came across this document, do you know if there was a factory program to cover the replacement of the air vent, condensate tank, and gas line as it describes a kit with those parts, covering labor, and return of the gas line along with a water sample?

    bosch-climate.us/files/201204202157500.6720643030_03%20GB142%20Service%20Kit%20Installation%20Instructions_en_12.2011.pdf