Quick answers to the most common Z1 questions about zeroing, alignment, burrs, the auger, retention, cleaning, and grind settings. Each answer links to a full step-by-step guide. These answers are for the Z1. Z2 owners, see Z2 Quick Answers.
User manual and videos
User manual: view the Z1 and Z2 user manuals at https://zerno.co/pages/knowledge-center.
| Video | What it covers |
|---|---|
| Quick set-up guide | Unboxing and first setup |
| What's included with your Z1 | Everything in the box |
| Workflow overview | Daily workflow, RDT, and reducing retention |
| Installing and swapping blind burrs | Burr swaps and setting the zero point (zero point at 18:25) |
| Swapping the prebreaker and auger | Changing the auger |
| False chirp phenomenon | What false chirp is and how to clear it |
How do I set (calibrate) my zero point?
Your Z1 arrives with a set zero point and is ready to use. Zeroing the dial needs to be done after a burr swap, because different burr sets have different dimensions.
- Remove the wood accent piece from your front assembly.
- Loosen the knob by 1 to 2 full turns, then turn the grinder switch on.
- Begin tightening the knob until you hear the first burr chirp, then promptly turn the grinder switch off. Running your grinder for a prolonged amount of time while the burrs are touching can wear out the burrs and damage your grinder.
- Using the 2.5mm screwdriver, hold the knob with one hand and loosen the center screw. 1 to 2 full turns should be enough. Do not remove the screw. The micron dial, located behind the knob, should now move freely and independently of the adjustment knob.
- Set the dial to 0 with one hand while holding the knob with the other, then tighten the center screw until snug (but not overtightened).
- Replace the wood accent piece.
Important: make sure your burrs are not touching before turning the grinder on. We recommend turning the dial a full turn coarser before turning on and verifying your zero point calibration.
Video: see 18:25 of the blind burr install video. Full guide: Setting the Zero Point on Your Z1.
Do you calibrate the Z1 based on first chirp or burr lock?
For safety, we calibrate based on first chirp.
What is the false chirp phenomenon?
Sometimes grind accumulation on the surface of the burrs causes a false chirp: a sound that mimics the burrs touching, along with noticeable dial resistance when you try to make a grind adjustment. It is most noticeable in burr sets that have polishing flats, such as the SSP HU blind burrs. Watch the false chirp phenomenon video for visual instructions. Full guide: Troubleshooting: False Chirp and Zero Point Shift on the Z1.
How do I swap between burr sets?
Our blind burr design allows for easy swapping using the Magnetic Burr Removal Tools. After using the removal tools to remove the installed burr set, use the cleaning brush to remove any leftover grounds before installing the new burr set. These tools are both included with your Z1.
Traditional burrs: remove the 3 blind burr screws from behind the burr carrier to make room for the traditional burr set screws.
Set screws: older versions of the Z1 use radial set screws to secure the blind burrs in the burr carrier. Z1 models delivered after July 2024 include upgraded burr carrier magnets and no longer need the radial set screws.
Video: blind burr install. Full guide: Changing Burrs on Your Z1. Burr stuck? See Troubleshooting: Stuck Burr on the Z1. Need a replacement screw? See Replacement Screws for Your Z1.
How do I swap the auger on the Z1?
- Use the 2.5mm Wera screwdriver included with your Z1 kit to remove the two front assembly screws.
- Pull out the prebreaker assembly.
- Remove the three 2mm screws on the back face of the assembly to free the prebreaker (auger).
- After swapping, replace the 3 screws and put the prebreaker assembly back in the grinder.
- Return the front assembly to its original position.
Video: auger replacement. Full guide: Changing the Auger on Your Z1.
How much retention is expected, and how do I minimize it?
It is normal to see about 0.1 to 0.3g of retention on any given grind.
Retention can be caused by many factors, the two most common being environment and beans. To minimize it:
- Before grinding: use your RDT bottle to spray your beans with water 1 to 2 times.
- After grinding: firmly tap the top of the open funnel with the palm of your hand while the grinder is on to clear leftover grounds from the chute. Here is a video that shows the process.
Note: you should not need to remove the chute, and we do not recommend using the Z1 chute as a knocker, as it can scratch or damage the chute and dosing cup.
Full guide: Z1 Grind Settings, RDT, and Retention.
How do I adjust my grind settings?
As a general best practice, make adjustments while the grinder is running so no particles get caught between the burrs. You may hear short chirps while adjusting (see the false chirp answer above).
Recommended starting points: espresso 200µm, pour over 625µm. Full ranges and dialing-in tips: Z1 Grind Settings, RDT, and Retention.
Are there maintenance tips for prolonging the life of my grinder?
We recommend disassembling and cleaning the grinder about every 50 uses, or as needed. This includes brushing the burr carrier to remove loose grounds, reseating the burrs, and resetting your zero point. We recommend hand-washing all accessories and removable grinder components to protect the materials, especially the magnetic components.
How do I clean the grinder?
Cleaning is best done by removing the internal components of the grind chamber and using the brush included with your order. Removable components include the front assembly, burrs, prebreaker, chute, and funnel.
During reassembly, push the prebreaker fully back onto the grind shaft and make sure the prebreaker key is engaged. When it is done correctly, you will feel a spring action providing resistance.
Full guide: Opening, Cleaning, and Closing Your Z1.
What should I do if my grinder is making unusual noises?
First check Troubleshooting: Vibration or Unusual Noise on the Z1 and Troubleshooting: Z1 Stalls, Struggles, or Stops With a Loud Noise. If these steps do not work, please contact support at info@zerno.co with a short video of the sound.
More Z1 guides
Z1 Will Not Turn On (Replacing the Fuse)
Small Fixes and Common Z1 Questions
Z1 Specs