fobbing when changing a new keg


cellarbuoy needing primingHi,

I was wondering if you can help this might be a really stupid question/problem I have.I have worked in loads of different pubs over the years but currently the pub i am in now has a problem when changing kegs (beer,larger,cider) every time we hook up a new keg to the line the first pint that gets pulled off its fobbing you get about 3inchs of the alcohol and the rest is just froth this happens for about 2 more pints until the alcohol starts to flow through normal,I have never experienced this before with all the other pubs i have worked in and was wondering if there was a way to prevent it as on average for every keg change we loose two pints from both pumps.

The cellar is always clean the lines cleaned every week there is no kinks in the lines.


  1. hi matey
    check you plunger’s on the bottom of the fob (cellar bouy)it sounds like the plunger’s are left in on the clean position.pull them out and try again if this isnt the problem come back on here we shall try something else.
    good luck

  2. Yes it sounds like the float isn’t sealing the line when the barrel is empty. As TIB says cellar buoys or Fobs have two positions the serve position and the clean position. If you leave it in the clean position when the barrel is empty the line fills up with gas and this would take a couple of pints to flush the gas out of the line.

    If you look at this page and let us know which fob you have we can be more precise.

    There can be a plunger but there can also be a switch depends which type you have.

  3. Thank you i will give it ago and see what happens we have both plungers in the cellar let you know in next few days to see if it works

  4. When the float or ball drops inside the chamber it normally seats on an o ring I have seen this o ring coming out of position at times if this is the cause you will have to call your tech rep out to reposition it.
    all the best.

  5. Hi This happens to me too I have checked the cellar-buoys all look ok could this be happens as the cellar is small and i have to move barrels as they are not stored in the cellar there in a lock up maybe there too warm would this be the issue or maybe there not settled long enough

    • If your containers are stored in a warm place then this can cause problems when you connect up in a chilled cellar. As a container get warmer gas will break out from the liquid causing fobbing, gas pressure would need to be adjusted to compensate for this. However this can cause other problems. The best solution, if possible would be to store it in the cool cellar 24hrs before use.

Do you have a better answer? Leave a reply or an opinion