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Reservoir tank running down quickly

Since putting in a new vacuum breaker and safety valve, I've noticed that the water level in my reservoir has been running down when the machine is idling at a very noticeable rate. I finally got around to looking inside today, and I noticed that water is continually bubbling out of the vacuum breaker. Could that be the cause? Here's what it looks like:

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  • hi matthew

    what pressure is displayed on the gauge?

    kind regards

  • Hi Reiss,
    The pressure is 1.1 bar.
  • hi matthew
    ok, so that rules out the possibility of the boiler having over filled
    im also assuming you've not got water running out from under the machine, or any other obvious sign of leaking
    my next step would be to depress the stem of the anti-vac valve repeatedly in quick succession with the system pressurised so that short bursts of steam are released each time you depress the valve stem
    the objective is to dislodge the small piece of grit that is most likely lodged in the valve and preventing a complete seal
    obviously use a pencil or similar object to keep your hand a sufficient distance away from the steam as it is released, to ensure you do not receive a steam burn
    i would depress it about 10 times in quick succession and repeat if necessary
    if that doesn't solve it then remove the valve and inspect for grit, or worst case a tear, nick, or cut to the o-ring or poor machining in the seat of the ptfe insert that the o-ring needs to seal against
    let me know
    kind regards
  • There's no sign of leaking in or below the machine. I'll go through the processes you outline and let you know the results.

    Best wishes,
  • Yesterday morning, I took the top and side off the machine and found that the safety valve seemed to have cured itself overnight. I left the sides off and checked it every now and then during the rest of the day and evening, but the problem did not return. I'be been busy with other things today, but I have noted that the rate of water loss in the tank seems to have retuned to normal (or at least what I'm used to).

    I suppose everyone who leaves their machine on all day is familiar with hearing the pump occasionally fill the boiler to compensate for water lost from leakage/evaporation. The question is what is the normal rate of depletion. Have you ever measured that?

    Best wishes,

    PS I found your Kafatek Max/EK 43s review very interesting.
  • Hi Matt

    To all intents and purposes there should be zero evapouration from the system

    The pump may very occasionally (once a day at the absolute worst) come on when the machine is idle, but this should only be the result of the boiler level being right on the edge of where the level probe trips; it should not be a response to water losses from the system

    Water leaks are usually easy to spot as you end up with water underneath the machine eventually - check that you haven’t got a slow drip from the portafilter too

    However steam leaks are more difficult to spot as they will not always condense inside the machine and create a visible leak

    To locate a steam leak I like to hold one end of the cardboard former tube used for products like kitchen cling film to the suspected site of a steam leak and the other end to my ear and listen for a hiss. I find this technique simple and effective

    Let me know

  • FWIW, earlier this year I noticed I was having to fill the tank more often than I was accustomed to doing. I finally diagnosed the cause as a steam leak coming from the safety valve. I replaced the valve, and the difference is astonishing.
  • hi matt

    did you use loxeal 55-03 on the threads of the safety valve and anti-vac valve when you replaced them a month or so back?

    use the cardboard tube method, as i describe above, placing it entirely over each valve and listening for hissing


    if you did not use loxeal 55-03 on the threads and one or both are leaking i suggest you take the valve that is leaking off and apply some, or 6 wraps of plumber's thread tape (ptfe) in a clockwise direction so it does not tear up as you turn the valve onto the thread

    kind regards

  • Thanks, Reiss. I will try those suggestions and report back. I'm busy this weekend, but I should be able to work on the machine on Monday. Although I have some Loxeal 55-03, I didn't use any when I installed the new safety and vacuum valves. Should I use that or plumbers tape when I reinsert them?

    Best wises,
  • hi matthew

    personally i hate ptfe tape, but it is inexpensive and many people have some in their tool box from the last plumbing job they did

    if you have the loxeal 55-03 absolutely put some on the threads of both valves

    whilst it is only a 10mL bottle it should last for years and years as you only need to apply one drip of 55-03 on opposite sides of the thread, about 3/4 of the way down the thread; in this way it will not drip off the bottom of the thread into the boiler while it is setting and the loxeal 55-03 will be carried up the thread as you turn the fitting into the boiler

    leave it to dry for at least 30 minutes before turning the machine back on

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