I have an 18 year old AC/Furnace unit. It has never given me any issues until today. I will note, however, that the condenser (the fan unit that rests outside) makes a loud noise when the AC is turned on, almost like it is struggling to turn on. This has gone on for about 3 years now. Anyhow, today, after arriving home, I noticed the AC was off. I checked the thermostat and it said it was on, but the unit was clearly off. I checked the breakers and noticed all but one breaker was in the off position. The one that was in the off position had a tag with the word "heater" next to it. I manually turned it on and could hear the condenser unit start up, but then the breaker tripped again. So, I went inside, turned the AC thermostat off, then went back outside, turned the breaker for the AC off and then back on, and then turned the heater breaker back on. I then went back inside my house and turned on the AC. To my surprise, the AC came on. I went back outside to the breaker box, and none of the breakers tripped. Should I be worried about this? I have never had a breaker trip in the past. I am a little more worried because I had my dryer break down this week. The cause is unknown, but I had to replace the heating element due to it cracking. I am wondering if there is an electrical problem, or if this is just something I should forget about. Any input is appreciated. Thanks.