The button on the mash tun stays lit when the control box heating socket is providing the mash tun with full power. In this case, the heating status bar on the control box screen will show 100%.
What you're seeing
While your G30 is heating, the switch on the mash tun sometimes stays solidly lit, and other times flashes orange. Both are normal — they just mean different things.
Solid light = full power
When your control box needs to deliver full power to heat the mash tun, the switch stays lit continuously. You'll also see the heating status bar on the control box screen read 100%.
Flashing light = fine-tuning near your target
Once the temperature gets close to your target — within about 2 degrees — the control box eases off full power to avoid overshooting past your set point. Instead of sending a constant blast of energy, it starts pulsing the power on and off rapidly, delivering smaller bursts rather than one steady stream.
That rapid pulsing is exactly what causes the switch to flash orange. It's a visual cue that the control box is actively fine-tuning the heat to land right on your target temperature, rather than overshooting it.
Why it does this
This pulsing method gives the G30 much finer control over temperature as you approach your set point — instead of a blunt "full power or nothing" approach, it can nudge the temperature up in small, controlled steps. The result is more accurate, more consistent temperature holds during your mash.
Bottom line
If your G30 is flashing orange as it nears your target temperature, that's the system working exactly as designed — not a fault. Nothing to troubleshoot here.