Comgrow 3D Printer Filament Dryer Box: problems, parts and running costs

Checked: 2026-10-17

Summary

The first-generation Comgrow dry box takes two 1 kg spools and heats to a hard 50 °C in 40/45/50 °C steps, with a 6–12 h timer and a real-time temperature/humidity display. Its running cost is small on paper — about $7.99 a year of electricity at the 48 W nameplate rating plus optional desiccant — but the 50 °C ceiling rules out PETG, ABS, nylon and TPU. It is a good buy only for PLA-dominant shops that vent the lid and find it near its historical under-$50 price.

Common problems and fixes

50 °C ceiling excludes higher-temperature materials — owners call 50 °C workable for PLA, marginal for PETG and not high enough for ABS, nylon or TPU; Sovol’s own guide lists 65 °C for PETG and ABS, 55 °C for TPU and 75 °C for nylon, all above this ceiling. Fix: use it only for PLA; for anything hotter, move to a dryer rated above 50 °C. [5][18]
Slow moisture removal in a sealed box — one owner measured only about 1% humidity reduction after 12 h and had to prop the lid open. Fix: vent the PTFE outlet plugs or crack the lid while heating, then close up after the spool and air cool. [6][15]
Display reads optimistic — after 1.5 h one owner logged 41 °C and 33% RH on an external sensor against 50 °C and 26% on the dryer’s own screen; the successor SH02 shows a similar ~5 °C offset. Fix: treat the screen as a rough guide and rotate spools for even heating. [7][9]
Heat radiates downward — the underside gets hot enough that a community member designed 3D-printed spacer feet to lift the unit. Fix: raise it off the desk on spacer feet. [10]
12 h maximum timer — long drying jobs must be restarted manually, unlike unattended 24–48 h conditioning on some dryers. Fix: restart the cycle for long jobs. [1]
Discontinued and undocumented warranty — Comgrow no longer lists this SKU and its current 1-year warranty and 30-day return policy apply to the current lineup; no dryer parts catalog or part numbers exist for this model. Fix: buy from a seller that confirms return terms in writing. [2][12]

Parts and consumables

Silica-gel packets (optional) — Dry & Dry indicating rechargeable silica packets, 10-pack at $8.99 at Walmart (October 2026); they can be recharged and reused and have no fixed replacement schedule. [17]

Yearly running cost

Using the manual’s 48 W rated figure as if the draw held for every minute, drying 8 hours twice a week (832 hours a year) would use about 39.94 kWh, or $7.99 at $0.20 per kWh; one 8-hour cycle is about 0.384 kWh, roughly $0.08. Add the optional desiccant at $8.99 and a first-year budget under these assumptions is about $17, exclusive of sales tax. This is an illustration from the nameplate rating, not a wall-meter test, and it excludes parts, failed prints and the filament itself. [19][17]

When it is a good buy

Under $50 — the historical position: community threads show the Comgrow chosen at about $47 over a $45 single-spool alternative, and it makes sense for a PLA-dominant shop that vents the lid and treats the display as approximate. [14]
Newegg marketplace — lists a Comgrow-branded 40–50 °C two-spool dryer at $81.88–$86.99 depending on the seller (October 2026). [13]
Sovol SH01 — a comparable 50 °C two-spool machine at $39.99 manufacturer-direct; the better buy when its support and shipping are equivalent. [14]
Sovol SH02 — $59.99, heating to 70 °C with a 150 W PTC heater; the better choice for PETG or TPU that need above 50 °C. [15]
Creality Space Pi — $66.00 single-spool, 45–70 °C with a 0–48 h timer; the better choice when only one spool is active. [16]