Choose the correct maintenance branch
A replacement nozzle may change which official cleaning route applies. Check the installed component rather than relying only on the printer’s name or factory specification. Do not put a needle through a high-flow nozzle by copying instructions for a standard nozzle.
A faint extruder click alone is not enough to establish a clog; Prusa notes that gearing can also produce a light click. If the actual problem is extrusion or missing layers, use the separate clogged-nozzle diagnosis before choosing a cleaning intervention.
Prusa Research · www.prusa3d.comPrusa Knowledge Base · help.prusa3d.com
Respect the procedure’s temperature and power state
The specification does not tell you when to heat, cool or switch off during a particular procedure. Follow the ordered Prusa instructions for the nozzle you have. Heated parts can cause severe burns; do not replace that sequence with a blanket “heat to maximum” instruction.
Stop if the nozzle type is uncertain or the prescribed handling cannot be done safely. Give support the installed nozzle type and the observed symptom. Neither these ratings nor this page authorize disassembly beyond the applicable official procedure.
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.
01Which included MK4S nozzle should maintenance instructions be matched to?
Match the instructions to the included 0.4 mm high-flow brass CHT nozzle, unless it has been replaced. Prusa’s clog guidance excludes the acupuncture-needle method for a high-flow nozzle; do not borrow that branch from a standard-nozzle procedure.