ThermoWorks, the brand behind professional cooking tools like the ThermaPen MK4 and the ThermoWorks Smoke, has launched a new accessory called Billows.
Billows is a charcoal airflow management fan that gives you reliable temperature control for grills and smokers without constant attention to the coals. It integrates with ThermoWorks’ Signals thermometer system to create a practical, easy-to-use temperature monitoring and control solution for slow-and-low cooks.
ThermoWorks Signals is a four-channel digital thermometer that monitors up to four temperatures simultaneously. The splash-resistant Signals unit pairs with the Billows fan and the free ThermoWorks app, so you can view readings and adjust settings from a smartphone or tablet, or run the Signals unit in standalone mode without wireless connectivity.
Billows attaches directly to charcoal grills and smokers and is compatible with existing and new Signals units as a dedicated accessory. While pit controllers are not a new concept, adding automated airflow control to a trusted thermometer makes long cooks more convenient and reduces the risk of temperature drift.
The Signals system includes four high-temperature, commercial-grade probes with color-coded rings: three meat probes and one grate probe with a clip for measuring cooking surface temperature. The package also contains a 12-volt charger and a USB-C cable to recharge the built-in battery or keep the unit powered during long cooks. Strong magnets on the back let you mount the device securely to metal surfaces.
Signals connects to mobile devices via Bluetooth or Wi‑Fi for remote monitoring, but it can operate independently. The ThermoWorks app is straightforward and includes data logging and graphing features that track temperature over the course of a cook. The Signals housing is sealed and splash-resistant, though not submersible, and the rechargeable battery lasts up to about 16 hours. The display is backlit and six buttons allow full control in standalone mode.
The Billows fan plugs into a USB-C port on the side of the Signals device. Note that when the Billows fan is in use, the Signals unit needs to be powered via the included adapter.
In hands-on testing we used hardwood lump charcoal in a Kamado-style cooker to see how the fan and controller handled varied charcoal sizes and dust. Lighting the charcoal in several spots and engaging the Billows fan brought the cooker up to temperature faster than a passive fire, and grate temperature stabilized within about 30 minutes. We observed steady, blue-tinged smoke with controlled airflow through the vents.
We tested an overnight pork butt cook. The meat probe was positioned in the thickest part of the shoulder and the grate probe clipped near the meat. After initial monitoring, we left the controller to maintain the cook overnight. The Signals app’s graphing showed temperature trends through the night. Despite a mix of uneven lump pieces and an overnight weather shift that might have reduced airflow, the Billows and Signals adjusted and held the set temperature with acceptable stability.
Over the course of the cook, the controller held a 220°F set point within roughly ±10°F, which is practical for low-and-slow barbecue. Connectivity to the app and cloud remained stable, allowing remote checks while away from the grill.
Signals™ 4-Channel Wi‑Fi/Bluetooth BBQ Alarm Thermometer — Key Specs
- Probe Range: -58 to 572°F (-50 to 300°C)
- Cable Max Temp: 700°F (370°C)
- Accuracy: ±1.8°F (±1.0°C) from -4 to 248°F (-20 to 120°C); ±3.6°F (±2.0°C) outside that range to 392°F; ±5.4°F (±3.0°C) up to 572°F
- Max Sound Volume: 90 dB
- Wireless: Wi‑Fi 802.11b/g/n (2.4 GHz)
- Bluetooth: Version 4.2, line-of-sight up to about 95 feet (device dependent)
- Approvals: FCC, IC, CE, RCM
- Water Resistance: IP66 splash-proof
- Operating Range: 32 to 122°F (0 to 50°C)
- Battery Life: Rechargeable, about 16 hours; Charging time ≈12 hours
- Charger: USB-C cable and 12V adapter included
- Display Size: 1.88 H x 3.97 W inches
- Product Size: 3.26 H x 5.19 W x 1.92 D inches
*Manufacturer specifications.
Test Data
- Probe 1: boil 211.5°F | ice 32°F
- Probe 2: boil 211.7°F | ice 31.5°F
- Probe 3: boil 211.2°F | ice 31.8°F
- Probe 4 (Grate): boil 211.5°F | ice 32.1°F
Billows Fan Accessory — Key Specs
- Airflow: 46 CFM
- Operating Temperature: Rated to 500°F (260°C)
- Opening Size: 1.18 x 1.57 inches (30 x 40 mm)
- Weather Resistance: Weatherproof
- Power: 12V supply
- Controller Temperature Accuracy: ±1.8°F
- Stability: ±10°F typical
**Manufacturer specifications.
What We Liked
ThermoWorks continues its tradition of thoughtful design and reliable performance. For Signals owners, adding the Billows fan converts the thermometer into a full temperature control system, offering an economical and well-engineered upgrade. The USB-C connections are practical and serviceable, and the Billows housing uses heat-resistant plastic that won’t rust. Its 46 CFM fan manages challenging airflow situations, and there’s even an optional connection kit to run two Billows from a single controller for very large cookers.
What Could Improve
Our beta unit had a spring that was fiddly to attach to the adapter, though this may be resolved in production units. An optional external 12V battery pack that could power the Billows for extended periods would be a useful accessory for remote or off-grid cooks.
Who Should Consider It
Billows and Signals are well suited for anyone cooking with charcoal in ceramic, stick burners, drum cookers, or barrel smokers. Backyard pitmasters, competitive cooks, and professional caterers will all benefit from the automated airflow control and accurate temperature monitoring.
Final Thoughts
ThermoWorks designs products in-house with a focus on accuracy, build quality, and user experience. Billows is an affordable add-on—priced at $59.00 at launch—that pairs neatly with the Signals thermometer to create a dependable pit controller system. If you already own Signals and want automated airflow control, Billows is a straightforward, practical upgrade that simplifies long cooks and helps maintain consistent temperatures.
