Add factory reset process for water drivers

docs/Guides/calibration/Water sensors.md

@@ -251,6 +251,16 @@ control conductivity com cal,high,80000
 
 After this steps the **two point calibration is complete** and the readings **will change**.
 
+!!! warning "Values always at 0 for EC?"
+    If you see 0 values, no matter what you do with the probe, it might be that you need to follow the [factory reset procedure](#factory-reset-procedure)
+    ```
+    control conductivity com r
+    0,0,0.00,1.000
+    control conductivity com r
+    0,0,0.00,1.000
+    ...
+    ```
+
 ### Atlas DO
 
 You have two options for this calibration:
@@ -440,4 +450,53 @@ You only need to perform a single point calibration. This process is only necess
 
     ```
     control atlas temp com cal,[value of temperature from reference probe or temperature]
-    ```
+    ```
+
+### Factory reset procedure
+
+!!! info "Why is this needed?"
+    You may need to do a factory reset for water sensors for different reasons. However, the most common case is a wrong calibration process and it's very much related to a wrongful automatic temperature compensation of the sensor while calibrating the sensor.
+
+    To explain further: EC, DO and pH sensor readings are automatically compensated by temperature readings. If there is an existing temperature correction in the EZO driver, or there is a correction in the middle of the calibration process, the data available for the calibration process will be invalid. Follow the steps below to be make sure there is no correction while you calibrate the probes.
+
+Each EZO driver has it's independent calibration and status. This process needs to be done per **_driver_** (i.e. per EZO metric). To make a factory reset procedure for the EZO drivers follow the steps below:
+
+1. Make sure that the [Smart Citizen Data](/Components/boards/Data%20Board/) board will not take any readings while you follow the calibration process. The best option is to reset the configuration to the defaults. Make sure you [back-up your information](/Guides/firmware/Update%20the%20firmware/?h=bac#make-a-back-up-of-your-info) before:
+
+    - The config command will output your current configuration. Copy it and keep it safe:
+
+    ```
+    config
+    ```
+
+    - Then issue the default configuration:
+
+    ```
+    config -defaults
+    ```
+
+    - The LED should be red now (the Data Board is in [Setup mode](/Smart%20Citizen%20Kit/?h=setup#setup-mode))
+
+2. Issue the factory reset command to the _driver_ in question. For instance, for the _conductivity_ one:
+
+    ```
+    control cond com factory
+    0
+    ```
+
+3. Now you can check what the status of the device is:
+
+    ```
+    control cond com cal,?
+    ?CAL,0
+    ```
+
+4. Reset the kit
+
+5. Follow the calibration process as you would normally would. Remember that for _conductivity_ you may need to [re-issue the probe type](#set-probe-type)
+
+6. Reconfigure the kit using the `config` command, by putting back the information you backed-up before:
+
+    ```
+    config -mode ...
+    ```