1. Confirm the symptom
Watch filament during loading and extrusion. Inconsistent flow, curling and sticking to the nozzle, gaps or missing layers and loud extruder clicking can indicate a clog. A light click may indicate gearing, so do not diagnose from sound alone.
2. Match the procedure to the nozzle
Confirm whether the included high-flow nozzle or a standard nozzle is installed. Prusa's needle route is only for non-high-flow nozzles. Use only the applicable official branch; heated parts can cause severe burns. Stop if you cannot keep hands and tools within the stated safety conditions.
Prusa Research · www.prusa3d.comPrusa Knowledge Base · help.prusa3d.com
FAQ
Original Prusa MK4S frequently asked questions
Each answer stays within the facts and sources shown on this page.
01What are common MK4S nozzle-clog signs?
Prusa lists inconsistent extrusion, filament curling and sticking to the nozzle, gaps or missing layers, and extruder clicking. A light click may indicate gearing instead, so a symptom is not a complete diagnosis.
02Should I use an acupuncture needle on the MK4S included high-flow nozzle?
No. Prusa says its acupuncture-needle steps do not apply to high-flow nozzles because of their internal geometry. Use the official branch for the installed nozzle; heated parts can cause severe burns, so stop if you cannot maintain the stated safety conditions.