The ThermoWorks Billows is the company’s first entry into the barbecue thermostatic controller market. It is designed to work in conjunction with the ThermoWorks’ Signals wireless thermometer. If you own an earlier version of the Signals, its firmware will be updated through the revised app and will work seamlessly with the Billows fan assembly.
Billows plugs into an adapter that connects the 12 V power supply and the Signals together. When connected, and a temperature probe is inserted into channel 4 of the Signals, the unit switches over automatically to thermostatic controller mode. The remaining three channels can be used to monitor food temps, and each has its own alarm settings. The user can set the cooker’s target temp either on the Signals itself or via the app. In fact, the Signals/Billows pair can operate independently of the phone app without any loss of functionality, a plus if you’re somewhere without an internet connection. In the absence of internet, the Signals can still communicate with your smart phone via Bluetooth, but you’ll have to stay within its rather limited range to monitor the progress of the cook. If you’ve configured your Signals to talk to your router, you can monitor and control the unit anywhere an internet connection is available.
This test was conducted using an 18.5” Weber Smokey Mountain smoker as the test platform. I used Kingsford charcoal briquettes as the fuel. Ambient temperatures were in the upper 60s Fahrenheit, and there was negligible wind. The Billows attached to the Weber using a hairpin spring that went through the vent opening. Heat resistant tape was supplied to close off the unused vents.
The fan is a high-output unit that brings the cooker up to operating temperature quickly. ThermoWorks suggests opening the upper exhaust vent only a fraction, and this worked well.
The initial target temperature for the cooker was set to 225°F. When the cooker’s target temperature is set, the unit automatically sets alarm limits 25° above and below the target, and this window is not adjustable by the user. When first fired up, the low temp alarm will sound, but it is easily silenced with the push of a button on either the hardware or in the app.
The graph below shows how well the product regulated the Weber’s temperature. After about 5.5 hours, the temperature began to fluctuate. This is a sign that the charcoal needs to be jostled to knock off its ash buildup. After knocking off the ash, the temp settled down again. At 2 p.m., I raised the target temp from 225° to 250°, and the temperature rose quickly. At 3:45 p.m., I again raised the temperature, this time to 275°, and the temperature responded quickly again. Overall, the temperature regulation was excellent. (Click on the graph to see a larger version.)
The feature set for the Signals/Billows pair is pretty basic compared to other thermostatic controllers on the market. There is no provision to create multiple programmed steps that respond to either an elapsed time or a food temperature. This feature may come in a future app release. There is no open-lid sensing, a feature meant to prevent temperature spikes after opening the lid. However, I did not observe any spikes after adding the food or opening the smoker to jostle the fuel or to add additional charcoal, so perhaps this functionality isn’t required. Using the app, you can view the temperature vs. time for any probe, but you can’t view multiple probes on a single screen. You have to switch back and forth to view their plots, a process that requires several steps. The app doesn’t provide any feedback on the duty cycle of the fan, a feature that can give the user an indication that the ash needs to be dislodged or that fuel is running low. The app itself, running on a Samsung Galaxy S6, gets sluggish after hours of data collection, a problem that the manufacturer is addressing.
Overall, performance of the Signals/Billows pair is very good. Construction is robust and installation is easy. If you already own a Signals, the Billows is a way to add thermostatic control to your wood- or charcoal-fired smoker/cooker for only $59 – a real bargain. The lack of some features might be a problem for some users, but is likely to be a non-issue for many others. I would recommend this unit to anyone who doesn’t demand advanced features but wants a solid, well-made controller at a good price.
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Bill McGrath - Bill McGrath is AmazingRibs.com's Thermometer Maven. He has sophisticated equipment, an electrical engineering degree from Cornell University, and an MBA (almost) from UC Berkeley. Despite being mostly retired, he is still the person responsible for developing and updating all of ExxonMobil's training modules.