If you run a bright tank, you already know what a thermowell is: the sleeve that lets a temperature sensor sit inside the tank without beer getting at the electronics. What matters for carbonation is that the FizzWizz needs its own thermowell.
Why a dedicated well
FizzWizz calculates finished pressure from temperature. Accurate temperature in, accurate pressure out. If it shares a thermowell with your glycol control sensor, you’re stacking two instruments where one belongs, and you lose the clean reading the pressure calculation depends on.
Why a degree matters
CO2 dissolves more readily as temperature falls, so the pressure FizzWizz aims for depends on the temperature it reads. As a guide, water held at 10 psig carries about 2.69 volumes of CO2 at 0°C but only about 2.30 volumes at 5°C (University of Florida IFAS). That’s roughly 0.08 volumes per degree, so a sensor that reads even one degree off moves your finished carbonation noticeably. (Those figures are calculated for water; sugar and alcohol shift the exact values.)
Three ways to get one
- A spare thermowell already in the tank.
- A thermowell adapter fitted to your sample port, such as the Sample Port Thermowell Adaptor.
- The WizzStone-Combo, which has a built-in thermowell that carries both the ceramic diffuser and the WizzTemp temperature sensor in one assembly. See the WizzStone-Combo assembly guide.
Will your existing well work?
Two things to check. First, length: on the tank in the video, both wells reach at least a foot into the tank, and that length works fine. Second, position: the well in the back of the tank where the glycol sensor lives is spoken for, so use the other port. If you’re not sure what you’re looking at, send us a photo of your tank fittings and we’ll tell you which port to use.
Not sure which port is right? Contact us with a photo of your tank.