# Manual Operation with the Digital Controller
## Using the Digital Controller
The Digital Controller has 6 buttons which serve different functions depending on context
**Cycle/Back - navigation between On Screen options. Exit without saving. Hold when prompted to advance Profile steps**
**Select - Select the current option. Enter a Selection. Confirm a choice**
**Up - Increase hightlighted variable (Power, Temperature etc)**
**Down - Decrease hightlighted variable (Power, Temperature etc)**
 **Play/Pause - Turn Heating On or Off**
**Pump - Turns the Pump On or Off**
The Gen 4.0 BrewZilla can be controlled using the buttons on the digital controller or through the RAPT Portal.
### Using the BrewZilla without Connecting to WiFi
If you do not intend to connect your device to the RAPT Portal and hence do not want to utilise the Wi-Fi functionality of the controller you can choose to control the brewery using only the digital controller.
To remove the prompt requesting you to register your device to the RAPT Portal you will need to disable Wi-Fi in the settings. To do this press **Select** to enter the menu, then select **Settings**, then navigate using the arrows to the **Disable Wi-Fi** setting. Press **Select** to disable the Wi-Fi and the controller will then restart automatically.
If you decide you don’t want to register your RAPT Gen 4 BrewZilla to the RAPT portal and hence not use the Wi-Fi functionality of the brewery you will in turn lose a lot of the functionality of the brewerywhich is offered through the RAPT Portal. This includes features such as setting up complex mashing/brewing profiles, logging brews etc.
### Display Icons Legend
ICON
MODE
FUNCTION
Heating Relay On
WiFi Connected
Bluetooth Enabled
PID Enabled
Profile Running
Pump Enabled
### Setting the Target Temperature Manually
At the home screen Use the **Select** button until the **Target** Temperature is highlighted then press the **Up** or **Down** buttons to adjust the target temperature. The BrewZilla will only begin heating once the device has been energised by pressing the **Play**  button.
**Warning**: Do not press **Play**  to energise the device if there is no liquid in the vessel.
### Turning the Pump On or Off
Press the **Pump** button to turn the pump on/off. The Pump text will be coloured light blue when the pump is set to ON and coloured grey when set to OFF.
**Warning: Do not press Pump** **to energise the device if there is no liquid in the vessel. This will result in the pump running dry which can damage the pump.**
#### Adjusting the Pump Duty Cycle (Percentage)
For greater repeatability of your mash schedule, you can control the pump output by adjusting the duty cycle of the pump rather than using the ball valve on the recirculation arm to adjust the output of the recirculating wort.
To adjust the duty cycle of the pump, press the **Select** button until the **Pump** Percentage is highlighted then use the Up or Down buttons to change the pump percentage. If the pump percentage is reduced then the pump will cycle on/off to reduce the output.
Alternatively, you can hold the pump button while pressing the up or down arrows to adjust the duty cycle.
**Important: to minimise the risk of blocking the pump, always have the top screen in place when recirculating wort during the mash**
### Adjusting the Heating Power
Press the **Select** button until the **Heat** Percentage is highlighted then use the Up or Down buttons to change the heating power.
If you have PID disabled then it is best to set the heating power to between 30-40% during the mash to stop the temperature overshooting your set temperature.
Note: If **Distillation Mode** is enabled then the Heating power percentages will be locked to only power output using the elements -relay switching of elements is disabled in this mode.
### Temperature Probe Calibration
**NOTE**: In most cases calibration is not required. Only calibrate if temperature reading is inaccurate.
If you find that your temperature probe is not reading the correct temperature for example if is reading over or under 100°C when boiling at sea level then a 2-point calibration can be performed.
To calibrate the built in probe
1. Enter the menu by pressing **Select**
2. Use the Up or Down arrows to navigate to Settings and press **Select**
3. Navigate to **Calibration Point 1** and hit **Select**
**Calibration Point 1**
FIll your boiler with at least 5L ice water and measure the temperature of the water using a calibration thermometer such as a [KL23320 Digital Instant Read Thermometer.](https://kegland.com.au/products/digital-instant-read-thermometer-with-folding-probe?_pos=3&_sid=3794753ee&_ss=r) Wait for the temperature reading on both the RAPT Gen 4 BrewZilla and the external calibrated thermometer to stabilise as much as possible.
Then adjust the temperature shown on the RAPT Gen 4 BrewZilla (Calibration Point 1) to match the temperature measured on the external calibrated thermometer.
Press Select to lock in **Calibration point 1** and move on to **Calibration point 2**.
**Calibration Point 2**
Empty the boiler and fill with hot or boiling water. Alternatively bring the water already in the boiler to boiling point by setting the temperature to above 100C and the power to 100%. When the water in the boiler is visibly boiling measure the temperature of the water using a calibration thermometer such as a [KL23320 Digital Instant Read Thermometer.](https://kegland.com.au/products/digital-instant-read-thermometer-with-folding-probe?_pos=3&_sid=3794753ee&_ss=r) At sea level this will be 100°C.
Then adjust the temperature shown on the RAPT Gen 4 BrewZilla to match the temperature measured on the external calibrated thermometer.
Press **Select** to lock in this calibration point 2
Your RAPT Gen 4 BrewZilla is now calibrated.
**Pro Tip**: Instead of using ice water and boiling water to calibrate (which will give the greatest accuracy across the widest temeprature range) you can calibrate Point 1 at 65°C (Using a calibrated thermoemter and bringing the water to this temperature using the elements) and Calibrate Point 2 at boiling point (100C). This can give better accuracy in the mashing temperature range.
### Reset Temperature Probe Calibration
You can manually reset the temperature probe to the default settings.
1. NTC beta: 3950
2. NTC ref. temperature: 298.2
3. NTC ref. resistance: 100000
You can also select **Forget Calibration** in **Settings**. This will revert any saved calibration settings to default.
### PID Temperature Control
The Gen 4 BrewZilla includes a setting to enable **PID Heating**. The default settings for the PID coefficients are shown in the Default Settings table. These coefficients should be considered a baseline and will need to be adjusted in most cases to acheive a reasonable result during brewing.
Note that due to the nature of PID temperature control, for ideal results you will need to manually adjust the PID setings for every batch, to compensate for variables such as water volume, desired temeprature range, grain quantity etc.
For example, when brewing larger or smaller batches, or creating wort of higher o lower gravities the PID settings will typically need to be adjusted in order to acheive the desired result.
PID can allow for precise temperature control. However, real world limitations as outlined bove mean that it is typically easier to acheive highly accurate, responsive and stable temperature control using a Bonded [RAPT Bluetooth Probe](https://kegland.com.au/products/rapt-bluetooth-thermometer-20-to-300c-20cm-htc-probe). Refer to the [Bluetooth Operation](https://app.gitbook.com/o/wlVNEjFt3UiW0iKxpA2G/s/UqN4sW0x2s4yh6iiT8NN/~/changes/129/equipment/rapt-brewzilla/bluetooth-operation) section for a detailed guide.
For a guide to PID settings David Heath has a fantastic video:
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**Select - Select the current option. Enter a Selection. Confirm a choice**
**Up - Increase hightlighted variable (Power, Temperature etc)**
**Down - Decrease hightlighted variable (Power, Temperature etc)**
 **Play/Pause - Turn Heating On or Off**
or Down 
arrows to navigate to Settings and press **Select**