Ex-Bradford City and Derby County prospect returns to full-time football with move to National League outfit
The 24-year-old began his career at Valley Parade, although failed to break into the first-team.
Spells with Derby County and Boston United followed before he established himself between the sticks at Avenue.
York boss Neal Ardley said: “George is a player who I did a lot of work on during the summer, and he was somebody that when I crushed the data and watched with my own eyes, was a goalkeeper who impressed me a lot.
“We’ve had him watched live twice now by the goalkeeping department, and with the way we want to move forward, we believe he will be an exciting addition to this team.”
The stopper has joined the Minstermen for an undisclosed fee and Avenue boss Bower has insisted the sale will allow for investment in strengthening his side.
He said: “George has been superb for us over the past two years and whilst we are disappointed to lose him, there is no doubt that he deserves the chance to move back in to full time football having shown an outstanding level of consistency and maturity whilst with us.
“I am pleased that we have been able to help another young player get back into the professional game and we wish him the best of luck.
“We have secured a transfer fee for George and that, along with his wages will be available to us to invest in strengthening the team. “