1. My indoor  unit is leaking oil on the floor.  The outdoor condensing unit will not turn on, but the indoor fan does blow air (hot air). What could be potential causes of the indoor oil leak on the floor?
The oil leak means that your unit has a refrigerant leakage problem.  Where the oil is leaking, you can cut out the insulation foam from the copper tube and open the case coil to find out where the leak is located and fix it.
2. My AC seems to work fine until the temp goes over about 92 and the humidity goes up.
There may be several possible causes:
  1. The evaporator coil is somehow restricted, which causes high head pressure during the hot day, therefore the coil needs to be replaced.
  2. The AC unit needs refrigerant charge.
  3. The outdoor unit is too dirty, so needs to be cleaned up.  ​​
3. The heater keeps turning on at random times during summer and start blowing warm/hot air.  How do I fix it?
You can shut off the power for the heater since it is not needed during the summer.  If you want to fix it, the thermostat needs to be replaced.
4. Do I have to get new home ac unit when the unit has refrigerant leak? Can’t I just fix the leak?
This depends on where the leaking is located.  If the AC’s copper pipe is leaking, you can fix the crack, which will stop the leak.  If the evaporator coil or condenser coil is leaking, and you have a R22 system (obsolete), the whole AC unit needs to be replaced.
​5. Does refrigerant leak when AC is off?
Refrigerant is not supposed to leak regardless of AC run or stop. If it leaks, you will have to find out where the leak is and fix it.
6. Why is it that my AC keeps turning on and off in a very short period of time?
The outdoor unit (AC) has low refrigerant pressure or has very high pressure. You will have to call for service on this.
7. There is frost inside my air handler unit, The pipes that go into the unit are very frosty. Is it normal? Or should I just let it defrost?
It is not normal, it could be caused by:
  • Dirty filter. 
  • Defective blower motor.
  • Low refrigerant pressure.
8. When I turned on AC, I noticed a short humming noise that lasted about 2 seconds. It repeats itself about every 3-5 minutes. The lights dims during this humming noise (2 seconds) and I heard the hum at the breaker in the panel during the "surge".
The compressor may have a problem starting. The system may also have refrigerant pressure problem.
9. I have heat pump system, sometimes ac runs fine and sometimes it will take a long time to run during night time. Repairman has replaced the thermostat, and charged the refrigerant for “low refrigerant problem”, but it hasn’t fixed the problem
Your heat pump may have the following problems:
1.  The refrigerant has been improperly charged.
2.  The defrost thermostat was defective and has caused the heat and AC to run at the same time.
3.  Your house has bad insulation, where the house absorbs heat in the daytime and radiates heat in the night time, forcing the AC to work longer to cool down the whole house
10. There is a click sound from thermostat, but nothing starts after the sound
Your indoor unit power maybe off or fuse burn out
11. heat pump unit shuts down when it is raining (both sprinkles and heavy rain). The thermostat is also blinking (which means that the compressor is not working properly). What is the cause and how do I fix it? 
If the rain stops your heat pump from working, then there’s something wrong with the outdoor unit. 
  • ​It may be water leaking into the control board.
  • contactor relays or wires have short out the electricity.
​You will need go to the outdoor unit to disconnect power, open the outdoor unit cover, and carefully check to see if water has gotten in there. ​
12. Why does my central air conditioner unit shuts off every evening? It cuts off and will not restart until late at night, when the outside temp cools down - with no changes to the thermostat.
There are two possible causes:
  1. Your power company may have your system set on the “efficiency program”, where they usually install a control box by the outdoor unit.  The box will shut your AC unit off during peak time of power consumption.  After peak time the box will restart the AC unit, which should save your consumption of electricity, but may not be comfortable to you since the AC is shutting off.
  2. Reset your thermostat according to your manual to run during the evening time.​​
13. The central ac unit is blowing warm instead of cool air. The blower is working and the outside fan is running also. But I can hear something trying to kick on while outdoor is running.​
Your ac unit capacitor is no good, a capacitor replacement and a hard start kit are needed.
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14. Why is my ac system freezing up?​
You may have:
  1. A dirty air filter.
  2. A dirty evaporator coil.
  3. Low on Freon.
15. ​The circuit breaker tripped after a storm so the breaker was reset, but the system starts and shuts off after 5 seconds
First replace the capacitor.  Turn on and test again, and if system shuts off again then the compressor needs to be replaced.
16. ​When I turn on cool air, the outdoor unit runs but the indoor unit makes a high whining sound and no air comes out of the vent.
Your indoor blower motor and blower wheel need to be replaced.
17. When I turn on the AC, it will run for 10 minutes, but it won’t restart again so I have to manually turn it off and on from the thermostat. How to I fix it?
There can be a couple of reasons:
  1. If the indoor unit is not running, the blower motor or circuit board might be defective.
  2. If the outdoor unit is not running, the thermostat wire does not have good contact, or the contactor or the circuit board is defective.​
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18. ​I noticed the AC wires were chewed through and bare wires are touching each other.  The control panels both work, but when commanded to blow air out, there is no heat and no AC. Is there a breaker?
You need turn the power off the unit and replace the wires.  There should be a breaker on the unit or close to the unit.
19. condenser unit is making a clicking sound.  I changed the capacitor, but it is still making a clicking sound, which seems to be coming from the fan motor.  What could be the problem?
You may have:
  1. A loose thermostat wire.
  2. Broken thermostat wire.
  3. Bad contactor.
  4. Freon low in charge.
20. ​My compressor is making an incredibly loud screeching noise.  Is it dangerous and why?
Your compressor may have:
  1. Mechanical problem.
  2. System is over charged.
  3. No Freon at all.
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