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SUNLU Filament Dryer S2

SUNLU Filament Dryer S2

By SUNLU · Filament Dryers · 3D Printing · More from SUNLU

  • Maximum drying temperature 70C
  • Dual 360-degree PTC heating plates with bottom circulation fan
  • 48W max power
  • 4.6-inch LCD display with real-time humidity readout
  • 265x274x118mm, 1109g

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Summary

A compact single-spool filament dryer and storage box for FDM 3D printing, running from 35 to 70 °C with a 4.6-inch touch screen that shows chamber temperature and humidity. The one thing to check before buying is the sealed chamber: with the lid shut, owners report humidity stalling near 40%, so plan to prop the lid or print a spacer.

Strengths

  • Heats from 35 to 70 °C, enough for PLA, PETG, ABS, TPU, PA and PC.
  • Curved upper and lower heating plates cover most of the spool surface.
  • It doubles as a storage box and feeds filament to the printer while drying.
  • One-touch presets and a compact footprint suit a single-spool bench.

Weaknesses

  • The chamber has no active vent, and owners report humidity stalling near 40% with the lid shut.
  • One owner measured humidity rising from 51% to 70% while heating, then falling only after propping the lid.
  • Default drying is a fixed 6-hour cycle; continuous drying needs the 99:00 timer trick.
  • It handles one spool at a time, and SUNLU says it is not for high-temperature engineering filaments.
  • No spare-parts channel, service manual or user-replaceable parts were found.
  • Warranty duration is not stated in the manual, and using a non-spec adapter voids cover.

Verified specifications

ModelSUNLU FilaDryer S2; US store model SLUS-FD-S2-BK-US-NEW.
Temperature range35–70 °C, adjustable.
Default run50 °C for 6 hours on PLA with the LED off.
Timerfixed-time drying, adjustable across manual mirrors to 0–99 h or 1–99 h; setting Time to 99:00 disables the countdown for continuous drying.
Display4.6-inch LCD touch screen showing measured temperature, measured humidity, set temperature, drying time and material selection.
Heatingdual upper and lower heating plates plus a bottom circulation fan.
Chamber capacityspools up to 210 mm diameter and 85 mm width.
Filament diameters1.75 and 2.85 mm per the official manual; SUNLU store pages add 3.00 mm.
Power24 V, 2 A adapter; 48 W maximum draw, 0.05 W standby.
Working environmentambient 20–35 °C, relative humidity up to 90%.
Presetsone-touch profiles for PLA, PETG, ABS, TPU, PA and PC.
Dimensions265 × 274 × 118 mm; carton 275 × 285 × 122 mm.
Weightthree conflicting published numbers — 1109 g net (manufacturer), 1190 g including adapter (manual), 3.42 lb (retail mirror).
CertificationsCE-LVD, CE, FCC, PSE, ROHS, UKCA.
In the boxdryer unit, 48 W power adapter, user manual and PTFE tube spares.
Full research notes and sources

How it dries

The S2 heats with dual upper and lower plates and a bottom circulation fan, and a specialist hands-on test measured the chamber at 72 °C, slightly above the 70 °C spec ceiling. At the top of the range SUNLU warns that the spool must tolerate above 70 °C or it can deform.

The chamber is the weak point. It has no dedicated vent, so moisture escapes only through the lid seam and outlet holes. One owner reports humidity rising from 51% to 70% while heating and being unable to get below 40%; another new owner hit the same floor. A forum measurement on a SUNLU dryer found that propping the front a few millimetres dropped humidity about 10% in 30 minutes, and the same owner cut vent holes. All3DP’s drying guide says to leave the S2 lid ajar, Hackaday gives the same advice for Sunlu-type dryers, and a purpose-built spacer on Printables exists to do it hands-free.

Owners on the S2

Owners on r/3Dprinting generally like the hardware. One was pleasantly surprised by the curved top and bottom heating elements covering most of the spool, and others call out the compact footprint and one-touch operation. The recurring criticism is the sealed chamber, described above, and one owner reports a PETG feed problem into a Prusa Mk3S after six months of ownership.

Running costs and upkeep

There are no consumables: the only running cost is electricity. At 48 W maximum, a 6-hour cycle at full draw is about 0.29 kWh, and standby draws 0.05 W. Keep the lid on while drying to avoid heat loss, place the unit on a heat-resistant surface, and do not block the outlet holes. The manual’s troubleshooting covers a temperature that will not rise (replace an under-spec adapter, close the lid, reconnect the temperature probe) and fault code ER1 for poor probe contact.

Warranty cover is the open question: the manual lists void conditions but no duration, and no spare-parts channel, service manual or user-replaceable components were found. Below 10 °C ambient the unit heats slowly and the chamber can read below the display, which SUNLU calls normal.

Is it worth it?

SUNLU’s own store lists the S2 at $44.99, against a $79.99 compare-at, as of 2026-10-17. At that price it is reasonable for a single-spool PLA, PETG, TPU or ABS drying-plus-storage box; the 70 °C ceiling also spans PA and PC profiles. Between $50 and $65 it is fair value, and above $75 its fixed limits — one spool, sealed chamber, 70 °C cap and thin documentation — make it hard to justify.

Which model this is

This page covers the SUNLU FilaDryer S2, a single-spool dryer and storage box; the US store model is SLUS-FD-S2-BK-US-NEW and manual aggregators list EAN 6933582304379. The Amazon listing is ASIN B09XMT9SVX. Do not merge it with the S1 or S1 Plus (55 °C, 24 h timer), the S4 (4 spools, 320–350 W), the SP2 (modular, 250 W) or the E2 (110 °C).

Sources

Manufacturer:

Independent reviews:

Owner reports:

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