View Full Version : Air conditioning unit turns on and off
sean1010
Jul 15, 2014, 12:30 PM
Hi I'm new and I know it's summer time but our ac will kick on for 20 minutes and then shut off for 10. We have it set to 76. We have fans turned on through out the house and room darkening curtains but it doesn't seem to help. I don't remember this being normal last year. Could we have an issue or do you have any tips on what to do? All I can think about is how high our ac bill will be.
ma0641
Jul 15, 2014, 01:39 PM
That doesn't sound too bad, mine is about the same depending on heat and solar load. 76 is a bit low, 77-78 will save you money, particularly with ceiling fans. You save 1-3% for every degree above 72. You are better to have the AC running longer as it also dehumidifies. Running too short will ramp up the humidity and makes you feel hotter.
sean1010
Jul 15, 2014, 01:41 PM
Thank you.. That makes me feel better. I'll bump it up to 77
Studs ad
Jul 15, 2014, 06:14 PM
Raising your thermostat should help with the energy consumption, but if the air conditioner is cycling and it hasn't reached the temperature set point, you could have issues. Do you notice any white ice(frost) forming on the larger of the two lines either at the compressor outside or the evaporator inside on the furnace?
sean1010
Jul 15, 2014, 06:29 PM
No I haven't. The pipe inside was a little warm. I did notice when I put it on 77 the outside unit stopped. I cleaned around the unit. And it started back up again. I put it back to 76. Not sure if too much debri caused it (grass was mowed today.)
Studs ad
Jul 15, 2014, 07:59 PM
Any debris covering the cooling fins will decrease the effectiveness of the air conditioner. It may not be your issue, but it is a place most techs would certainly check. Sometimes it isn't enough to actually notice, or cause problems but the better the heat exchange the more efficient and capable the air conditioner is, so cleaner is better. If your coils ice over, it has the same affect as being dirty because it restricts air flow through the coils. That's why I asked about the ice on the line.
You didn't make it clear if the unit is cooling and reaching set point and shutting off and then restarting in 10 minutes, or if the unit is not reaching set point and shutting the compressor off for 10 minutes. One is normal and the other may not be.