Even though the boiler serial and Gas Council numbers for an appliance don't appear on any records, it's an easy process to locate these fields within the software.
On the web portal
Head to the Job Addresses tab on the website and select the property.
Tap on the "Gas Appliances" button to show all appliances at this address
Click the appliance to show its information. Serial and Gas Council numbers will be found under the "More Info" section:
On the App
Tap "Job Addresses" from the main menu, find and select the address.
Scroll to the bottom of the page and tap on "Appliances", then tap on the appliance itself to show its information: