The wires have to be rated for 20A which means they would be 12 guage (bigger for long runs) instead of the usual 14, all the way back to the panel. You shouldn't just replace a 15A breaker with a 20A breaker.
You must have a verified phone number and physical address in order to post in the Audiogon Forums. Please return to Audiogon.com and complete this step. If you have any questions please contact Support.