Head to your preferences and check your custom boil is set to match the corresponding boiling point for your elevation.

If you're not sure what your boiling point is - you can simply Google the altitude of your location and then Google the corresponding boiling point for that altitude.

There could be a few factors as to why the boiler is only reaching 99°C (210°F) such as ambient temperature, altitude and the thickness of the sugars in the boiling wort. 

Please change the boiling temperature to 99°C (210°F) as explained below. This will then allow the boiling stage to kick in once the desired temperature is reached.

Note: For every 500 feet above sea level, your boil temperature will decrease by 0.5°C (1°F). 

To change it on your app - see below:

1. Go to the 3 dots on the bottom right of the screen.	2. Then choose Preferences.	3. Then simply click on the Boil Temperature field and change the number.