On my job I am installing exhaust fans with heaters in every bathroom, so far I have installed 12 of them. When I started, I read the paperwork and they called for a 15 amp ckt and when I looked at the nameplate in the unit it reads 11.9 amps, everything is cool...Today I was looking at the actual box in came in and on the back it reads "20 amp ckt required"......With all the info am I Ok with it on a 15a breaker or does it need a 20?