Understanding Your Readings
What each FizzWizz metric means — CO₂ reg psi, Brite psi, and temperature — and what good values look like during carbonation and packaging.
Understanding your readings
The dashboard and the FizzWizz display show three core values. Understanding what each one represents makes it much easier to tell a normal run from a problem.
The three core readings
| Reading | What it measures | Where it comes from |
|---|---|---|
| CO₂ reg psi | Pressure at the CO₂ inlet port | CO₂_In pressure transducer |
| Brite psi | Pressure in the arm/head transfer circuit — the tank head space pressure | Brite pressure transducer |
| Temperature | Product temperature | WizzTemp sensor |
All three are visible on the FizzWizz display, in Test Mode, and on the dashboard.
CO₂ reg psi
What it should be: 30–40 psi, matching your regulator setting, and steady.
This is your supply pressure. It tells you how much CO₂ is available to push into the tank.
| Value | Meaning |
|---|---|
| Steady 30–40 psi | Normal |
| Slowly declining | CO₂ supply running low — plan a cylinder change |
| Well below the regulator setting | Regulator problem, or a failed CO₂_In transducer |
| Not matching the regulator at all | Ident A — By Symptom |
A declining CO₂ reg psi is one of the alerts the FizzWizz raises. Running out mid-batch stalls carbonation, and the batch then has to be rested so CO₂ can re-dissolve at the right equilibrium pressure.
Brite psi
What it should be: climbing steadily toward the finish pressure during carbonation, then holding.
This is the pressure in the tank head space — the pressure actually driving CO₂ into solution.
| Value | Meaning |
|---|---|
| Not near zero at rest | Brite transducer issue, or fluid inside the unit — Ident B |
| Climbing steadily toward target | Normal carbonation in progress |
| Flat, never climbing | A leak — see Carbonation & Brite Pressure |
| Climbing unusually fast | Leaking Head_Transfer solenoid, or a broken stone — Ident U |
| Not matching CO₂ reg psi when expected to | Brite transducer, or fluid inside the unit — Ident S |
Why Brite psi alone is not the whole story
Carbonation depends on both pressure and temperature. The FizzWizz calculates the finish pressure required for your target at the current temperature — so the same Brite psi means different carbonation at different temperatures.
This is why the unit recalculates continuously, and why a temperature error causes systematic carbonation error even when pressure looks perfect.
Temperature
What it should be: stable, and accurate.
| Value | Meaning |
|---|---|
| Stable at the product setpoint | Normal |
| Drifting or stepping | Probe, loom, or glycol system — Ident C / T |
| Implausible (impossibly low or high) | Faulty probe or internal loom |
| Plausible but inaccurate | Causes systematic under- or over-carbonation — run the Slushy WizzTemp Test |
Carbonation volumes are calculated from temperature. A probe that reads warm makes the FizzWizz calculate less CO₂ than needed, and the beer is systematically under-carbonated — while every pressure reading looks correct. This is one of the hardest faults to spot from the dashboard alone, and one of the most common causes of persistent under-carbonation.
During packaging
During kegging, canning, or bottling, the important reading is the pressure the packaging line sees. If you have a Foot Pressure Sensor fitted at the tank foot, that is the value to watch.
The foot pressure must stay at or above the finish pressure, or CO₂ starts coming out of solution. Once breakout starts it tends to run away and is difficult to stop.
Minimum foot pressure = (product depth in ft × 0.43 psi) + finish pressure
See Choosing a foot pressure for worked examples.
Quick reference
| Reading | Normal | Warning sign | Go to |
|---|---|---|---|
| CO₂ reg psi | Steady 30–40 psi | Declining, or not matching regulator | Responding to Alerts |
| Brite psi | Climbing, then holding | Flat, or climbing too fast | Carbonation & Brite Pressure |
| Temperature | Stable and accurate | Drifting or inaccurate | Slushy WizzTemp Test |
| Health badge | Online | Stale or Offline | Device Offline |