W-3301A Digital Thermostat Timer Switch DC 5-24V NTC Probe

W-3301A Digital Thermostat Timer Switch — Precise Temperature Control, Anytime

Take full command of your heating and cooling setups with the W-3301A Line Controlled Digital Thermostat Timer Switch. Whether you're managing an incubation chamber, fermentation vessel, aquarium heater, terrarium, or any DC-powered temperature-sensitive system, this compact controller delivers intelligent dual-mode temperature management with a built-in countdown timer — all in a plug-and-play USB package.

Key Features

• Dual-Mode Temperature Control: Easily toggle between Heating Mode and Cooling Mode for automatic constant-temperature maintenance — no constant manual adjustments needed.
• High-Precision NTC Waterproof Probe: Accurately senses ambient or liquid temperature across a wide range of -20°C to 120°C (-4°F to 248°F), making it suitable for demanding environments.
• 999-Minute Countdown Timer: Set a timed shutdown of up to 999 minutes with a single button press — ideal for incubation, fermentation, brewing, or scheduled heating/cooling cycles.
• Wide Voltage USB Power Supply: Operates on DC 5–24V input via USB interface for straightforward plug-and-play installation with no complex wiring required.
• Child Lock Safety Protection: After 30 seconds of inactivity, the device automatically activates child lock mode to prevent accidental setting changes. Unlock with a long press of the power button.

Specifications

Ideal Use Cases

• Egg incubators & reptile terrariums
• Home brewing & fermentation chambers
• Aquarium heaters & fish tank controllers
• DIY heating pads & seedling mats
• Small greenhouse or grow tent temperature management
• 3D printer enclosure temperature regulation

What's in the Box

• 1× W-3301A Thermostat Timer Switch (with NTC probe)

Made in Mainland China.

Note: Due to lighting and display differences, the item's color may vary slightly from product images. Please allow 1 mm–1 cm differences due to manual measurement.

For general guidance on electrical safety standards for consumer electronics, visit the U.S. Consumer Product Safety Commission (CPSC).

Frequently Asked Questions

Q: What power source does the W-3301A digital thermostat timer switch require?

A: The W-3301A operates on a wide input voltage range of DC 5–24V via a standard USB interface. This makes it compatible with USB power banks, USB wall adapters, and DC power supplies within that voltage range — no complex wiring or special installation needed.

Q: Can I use this thermostat timer switch for both heating and cooling applications?

A: Yes! The W-3301A features selectable Heating Mode and Cooling Mode, allowing it to automatically maintain a set target temperature by switching your connected device on or off as needed. It's suitable for heaters, cooling fans, Peltier modules, and similar DC-powered devices.

Q: How accurate is the NTC probe temperature measurement?

A: The included NTC waterproof probe provides high-precision temperature sensing across a range of -20°C to 120°C. The waterproof design makes it safe for use in humid or liquid-adjacent environments such as aquariums, fermentation vessels, and incubators.

Q: What does the 999-minute timer function do?

A: The built-in countdown timer lets you set an automatic shutdown duration of up to 999 minutes (over 16 hours). Once the timer expires, the connected device is switched off automatically — perfect for timed fermentation cycles, incubation stages, or scheduled temperature control sessions.

Q: How does the child lock feature work on this thermostat switch?

A: If the device is left untouched for 30 seconds, it automatically enters child lock mode, disabling the buttons to prevent accidental changes to your settings. To deactivate the child lock, simply hold the power button for a few seconds until the lock icon disappears.