Air carrier Captain reported a flight deck window anti ice failure followed by a cracked window during climb out.

Narrative

I was tasked with flying an aircraft from storage to heavy maintenance. The flight was operated on a ferry permit due to overdue maintenance items. I added several MEL items before we departed. Climbing through around 10;000 feet; we encountered a cloud layer and received an ICE caution message. At approximately 12;000 feet we received a L WSHLD HEAT caution message. I announced that I had the aircraft and the radios; and called for the QRC/QRH checklists. I glanced up to see if the windshield was accumulating ice and noticed a crack running from the bottom of the windshield to the center. I stopped the climb and began slowing. We relayed to ZZZ Center that we had an issue with our windshield and would be stopping the climb and returning to ZZZ. They issued a heading to the airport and told us to report the field in sight. No emergency was declared; and the remainder of the flight continued normally.Upon landing; we discovered the crack had grown in length since first noticed; and a second crack was observed from the center post moving towards the center of the windshield.