My K30 has recently started dumping grinds like crazy, but only intermittently.

What I mean is when I have the timer set to my usual 3.2s or so, that's usually what gets me 18g. But now one time it'll do 18g and the next it'll do something crazy like 29g. It looks like it's just blowing grinds out of the chute, and makes a hell of a mess.

Anybody seen issues like this?

Have you ever taken apart the grinder to clean it? Usually when this happens it's the silicone flapper at fault. It's either stuck open or clogged up. I would would clean the grinder thouroughly and think about replacing the silicone flapper.

How old is your grinder and how many shots have you put through it? I replace the silicone flapper about once every 300lbs in my shop (it's a cheap enough part and easy to replace).

I have taken it apart to clean it, but it's been long enough to do it again. Having a hard time finding the flapper. Are they only available from Mahlkonig directly?

Yes. Contact Brian at MK and he will get you squared away. I don't think anyone sells them. They are pretty cheap. If you plan on keeping your grinder for a while I would order 3-4 of them. I replace mine every few months.

Ellejaycafe wrote:Have you ever taken apart the grinder to clean it? Usually when this happens it's the silicone flapper at fault. It's either stuck open or clogged up. I would would clean the grinder thouroughly and think about replacing the silicone flapper.

How old is your grinder and how many shots have you put through it? I replace the silicone flapper about once every 300lbs in my shop (it's a cheap enough part and easy to replace).

IIRC there is a thread or a video that shows how to replace it.

Edit: Mahlkonig K30 shooting grounds out

Re-upping the conversation as I'm not having dumping, but clumping (rhyme completely intended).

I think the humidity/warm weather is playing a big role in this. I changed the flapper about 2 months ago, and recently (2 weeks ago) deep cleaned it.

Do you guys have experience with humidity, or how to keep the inside of the grind chamber dry/cool?

Thanks!

What coffee are you using? Anything with oils? I only ask because I operate in a giant lobby that's nothing but windows. The ambient temperature in the room is around 82-86 this time of year and the humidity is pretty darn high due to the revolving doors constantly bringing in muggy air. Even with those temps and humidity I experience minimal clumping using our flagship blend, a fully developed medium roast with spots of oil here and there. I would imagine using a darker roast would clump quite a bit more due to oils. I don't have any advice for you per say but the grinder shouldn't be clumping that much despite high temps and humidity. If I don't take it apart and it deep clean it once a week it clumps like crazy though (this is running 50lbs +\- 5lbs over 5 days) I take out the flapper and spin it around everytime I clean it. That way the silicone is constantly switching the direction in which the teeth of the flapper bend and declump. I find that really helps and makes them last longer. Maybe try flipping yours around? The teeth could be getting stuck wide open