The most common question I hear about cooking with charcoal grills is how to control temperature. How do you keep a charcoal grill at the ideal temperature without large swings? How do you prevent the temperature from rising or dropping during a long cook? There’s good news: Thermoworks now offers a device that addresses these concerns—the Thermoworks Billows Temperature Controller.
Enter the Thermoworks Billows
Thermoworks is a well-established name in temperature monitoring. Their products are used across multiple industries, and their best-known items include the Thermapen Mk4 instant-read thermometer and the Smoke and Signals wireless monitoring systems. Building on that reputation, Thermoworks introduced the Billows, a fan-based controller designed to regulate airflow to charcoal grills.
It’s important to note that the Billows is a fan that requires an external controller to operate. At present, the compatible controller is the Thermoworks Signals, a four-channel temperature monitor. That means the Billows (retail $59.99) must be paired with the Signals (retail $229.99), bringing the combined cost to about $289.98. This price point is comparable to other temperature-control solutions, and you also gain a versatile Signals unit that works independently for monitoring multiple probes.
The Billows is molded from hard plastic and designed to clip into the air intake of a charcoal grill. For example, on a Big Green Egg it clips to the bottom vent. It connects to the Signals controller with a supplied, custom cable. The Signals controller requires an AC power connection via the included adapter when the Billows is attached, which is standard for fan-equipped systems on the market.
The Signals package includes a grate-temperature probe that clips to the grill grate and plugs into the controller. With the Billows clipped to the grill, the Signals plugged in, and the grate probe connected, the system is ready to run.
There is no special pairing required—once connected via the provided cable, the Signals controller automatically recognizes the Billows fan. You set your target temperature on the Signals device, and the Billows adjusts fan speed to maintain that temperature using the grate probe as its primary input.
Online and Remote Connectivity
Operating the system from the Signals device is straightforward, but Thermoworks also offers a mobile app for remote control. The app, available for Apple and Android, lets you view temperatures, change set points and receive alerts from a distance.
The app supports both Wi‑Fi and Bluetooth connections, making it flexible for backyard cooks and mobile caterers alike. It displays the grate temperature and the set temperature, and it also shows readings from the other three channels of the Signals controller. Remember that the Signals is a four-channel unit—three channels are typically used for internal food probes and the fourth for the grate or ambient temperature.
Once connected, you can change grill temperature settings from your phone and configure high and low alarms. If charcoal runs low or a temperature spike occurs, the app will notify you—especially helpful during long smokes that can run 12 hours or more.
Real-World Performance
I tested the Billows on a Big Green Egg during several cooks. Here are the practical takeaways from those sessions.
What I liked
Setup and installation are simple: clip the Billows to the vent, connect the cable to Signals, attach the grate probe, and plug in the Signals power adapter. Pairing Signals with a phone was quick and intuitive—the instructions are clear and the app is user-friendly.
The fan helps reduce warm-up time because it actively pushes air into the grill. Thermoworks states the system will hold your grill within 10°F of the set temperature; in my trials the grill rarely fluctuated more than 7–8°F around a 275°F target, which is excellent stability for charcoal cooking.
Keep in mind that this type of controller is intended for low-and-slow, indirect cooking. It’s not designed to maintain extremely high temps (500–600°F), which could damage the grate probe and exceed the fan’s practical output.
What I didn’t like
The main drawback is the need to plug the Signals into mains power when the Billows is connected. While Signals can run from its internal battery by itself, the fan requires external power. An optional external battery pack would improve portability and allow use farther from outlets.
Another limitation is that Billows works only with the Signals controller. Some users may prefer a simpler, less expensive controller; compatibility with the two-channel Smoke would be a welcome option in my view, but currently Billows is tied to Signals.
Overall
Overall, the Thermoworks Billows paired with the Signals controller makes charcoal grilling and smoking much easier to manage. For cooks who want automatic temperature control while preserving charcoal flavor, the combo delivers precise, reliable performance and convenient mobile monitoring.
The Signals controller adds value with four-channel monitoring and Wi‑Fi/Bluetooth connectivity, though the combined cost and the need for mains power with the fan attached are factors to consider. For many enthusiasts, the improved temperature stability and the convenience of remote alerts will justify the investment.
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