Thank you for back flushing the heater core on my 2012 CTS, I had taken it to two different places to to flush the heater core, to fix the drivers side with low heat. None of them back flushed the heater core by itself, so it didn't fix the problem. Their recommendation was to replace the heater core at a cost of $2600. Your cost was $394.28 to back flush the heater core, drain the radiator and refill Heater working like new. Great job...thank you!