2011 Chevrolet Volt - Heater burns out every two years

my heater element burns out every 2 years. why?

If you’re referring to the heater in the O2 sensor, those usually burn out due to thermal shock.

Tester

Or are you referring to the electric heater for the ventilation system?

Here’s a discussion on it - have you posted this on Volt forums?
https://gm-volt.com/forum/archive/index.php/t-225450.html