SUNLU FilaDryer S1 Plus: problems, parts and running costs

Checked: 2026-10-19

Summary

Owners report the S1 Plus can read 55°C while chamber air measures 46–48°C, fan noise after about two years of use, and moisture that seems to stall despite heating. There are no manufacturer-required consumables, and SUNLU lists no spare parts for this model. At $39.99 direct from SUNLU it is a fair buy for PLA, PETG and TPU; above $50 for the dryer alone it is poor value.

Common problems and fixes

Temperature undershoots set point — a November 2025 owner reported 46–48°C chamber air while the display read 55°C, blaming thermistor placement; do not modify the heater, and contact SUNLU under the 12-month warranty instead. [8][4]
Fan noise after long use — December 2025 owners reported loud fan startup after about two years; that thread mixed fanless and fan-equipped S1 units, so the S1 Plus failure rate is unverified. [9]
Moisture may stall — the fan circulates internal air with no quantified outdoor exchange; some owners report RH stalling despite heating. Open and close the outlets per the manual; do not drill the box or cover vents. [6][7][10]
RH reading is not strand moisture — displayed 20–25% RH depends on temperature and sensor accuracy, and entry-level sensors can be inaccurate at very low RH, so a 20% reading does not prove a saturated spool is dry. [3][11]
Roller friction and fit — large, eccentric or cardboard flanges can turn poorly on the rim rollers, especially while feeding flexible filament; check dimensions and free movement. [2][7]
One spool and a 55°C ceiling — only one standard spool dries at a time and 55°C is too cool for nylon and polycarbonate; the S2 reaches 70°C. [1][13]

Parts and consumables

Heater, probes, LCD/control PCB, lid, rollers and feed-outlet plugs — no verified SUNLU US spare listings or standardized replacement schedule. [4]
Filament — not a dryer consumable; optional SUNLU store PLA additions are separate from the base item. [2]

Yearly running cost

A 6-hour cycle at the full 48 W draws 0.288 kWh; at an assumed $0.20/kWh that is $0.058 per cycle, and twelve cycles a month would be 41.472 kWh, about $8.29 a year at that assumed rate. No filters, refills or subscriptions are required: $0 per year in scheduled supplies. Spreading the $39.99 purchase over a hypothetical three years is $13.33 per year, excluding power and repairs. [1][2][9]

When it is a good buy

SUNLU direct, US plug, no filament: $39.99 on October 11, 2026, marked down from a crossed-out $59.99; site tiles sometimes show from $38.99. [2][14]
Newegg third-party: $74.49 from seller Nexus Drive, with a second indexed merchant at $93.99; neither is SUNLU-direct nor confirmed authorized. [15][16]
SUNLU S2: from $44.99 in the category listing, one page showed $45.99 with EU plug selected; confirm US-plug checkout. [13]
SUNLU SP2: from $49.99 for two 1-kg reels or one larger reel. [12]
Creality Space Pi Plus: $79.99 at Best Buy ($89.99 regular) for two spools. [17]
Editorial levels: under $35 new, authorized and returnable is unusually attractive; $35–$42 is good; $42–$50 is where you should compare the hotter S2; over $50 for the dryer alone is relatively poor value. [2][13]
Alternatives: choose the S2 for higher-temperature polymers, the SP2 for multiple spools, or the Creality Space Pi Plus for two spools at once.