This morning I noticed when I lift the handle the flow out of the group head is drips and not a stream. I removed and cleaned the filter but there’s no difference and, in fact, it still dribbles out of the group with the filter screen off. I regularly run Puly detergent and the blind filter so it should be clean. I use treated distilled water so scaling shouldn’t be the problem. I recently had to remove the cover to replace a plastic T fitting to stop a leak. I took a look around and things seemed to be in order. Maybe the water flow regulator needs replacing?

What’s the best way to determine the problem? Any hints greatly appreciated.

    thusband clean. I use treated distilled water so scaling shouldn’t be the problem.

    What do you remineralise your water with?

    Also, a video of the problem would help with diagnostics quite a bit.

    Welcome to the forum!

    thusband - I remineralise the same way, just at 0.5g per 5l. 😊👍

    As for the machine, very strange. What pressure reading do you get on the pump pressure manometer (not the group)

    Is the flow valve fully open?

    Have you taken the valve off and inspected? Have you being maintaining it, lubricating it etc?

    thusband I will make the assumption the pressure gauge is showing at least 9 bar brewing pressure?

    It’s unlikely that for some reason the valve isn’t opening enough, because there is nothing mechanically that can “slip” and make that happen, unless you’re paddle isn’t properly on the splines.

    I am going to guess that you don’t remove the valve mechanism regularly to lubricate it….I’m also going to assume that the machine is at least 6 months old or older? Based on all those assumptions, I’m going to guess that the jet might be blocked by a bit of shredded O ring. It could of course simply be blocked by something far less terrifying.

    Remove the flow control valve from the top of the group, screw out the central core, photograph everything, including down into the group jet. If 1 or more O rings are shredded, they need replacement. Lubricate the valve and replace it. Use a spanner with jaw protectors, or make some up. You may need a small “socket on a stick” to get the group jet out.

    you may have to remove the group jet itself and clear any blockage…..

    When replacing the valve be super careful to only screw it in with your fingers and not the paddle initially, so check the pin is properly lined up with the hole in the group jet! Watch the videos very carefully. Lubrication maintenance of this valve should be done every 3-6 months….and if fitting one, lube it first as i did (Dow Corning Molykote III, I have shares in this 😉). All the information you need is in the 2 links below.

    https://coffeeequipmentreviews.wordpress.com/2019/07/29/lelit-needle-valve-kit/

    https://coffeeequipmentreviews.wordpress.com/2019/08/30/acs-minima-with-lelit-flow-profiling-kit/

    All your assumptions are correct. I’ve had the Bianca a little over a year and lubed the cam assy once about six months ago but I’ve never lubed the valve assy. Common sense, I guess, would dictate that it be done but I can’t remember seeing anything about it in the literature that came with it. No excuses, though, I screwed up.

    I guess Bella Barista would carry anything any of the parts. First I’ll remove the valve assy and see what I need.

    Many thanks for your detailed explanation. I guess it’ll be Aeropress for a few weeks.

      There is nothing in the handbooks about it…just my recommendations for the valve assembly. I made those after Lelit sent me a flow control valve assembly to have a close look at and try in other machines. I took it apart and examined it, which led me to believe this component requires regular lubrication. I will contact Lelit and see if they will include the process in their hand book, or a link in the handbook to a Lelit insider video..

      If your o rings have degraded, they are penny parts. Link below is free delivery…buy 100 for £6 and share some with your mates. I say 100, because 2 are £3.24 or summat. You will see when you get on the site. Dimensions are 6.07 × 1.78 (EDPM)

      https://simplybearings.co.uk/shop/product_info.php?products_id=80010&vat_inc=true&gclid=Cj0KCQiAk4aOBhCTARIsAFWFP9GV4qZXJh5TzItk9jRuBRQNsAdinH45ovjyLth1dA48ba7kxe5GfTAaAvDFEALw_wcB

      Giphy - the amanda show nicksplat GIF



      ]

      Well I got down to the restrictor (I think that’s what it’s called) but I need a 7mm hex to remove it. I tried an imperial sized socket and it’s close but don’t want to strip it. I can tell, though, it’s really on there very tightly. Haven’t come across any o-rings yet. Heading down to Homebase.
      Here’re some images:
      https://photos.app.goo.gl/E9DMEDBkKBCQUxdy5

        thusband I can see some crud on the pin of the lelit flow control valve (clean it off), that could have been enough. Find some very fine wire or a needle to poke down the jet. Lube the O rings on the Lelit valve, pop it back on and see if it’s removed the blockage…remember fingers no paddle. Then once it’s on, you can probably use your fingers on the spline to open/close and see what the flow is like.

        If it’s OK, adjust the paddle for no flow when it’s not quite touching the case and fully left (off)

        Many, many thanks Dave! We’re back in business. Lesson learned. A little preventative maintenance goes a long way.

        It was pretty simple really.

          thusband Glad it’s now sorted…In a way a blessing, because you now know what needs maintaining in the flow control system and how…..one day you might even have 100 o’rings 😁