Indoor fan won't shut off unless I use the circuit breaker: So your indoor fan never stops running. You've checked the obvious... The fan switch on the thermostat is in the auto position, not the on position. You tried turning the thermostat to the off position, nothing works. The only way to get that pesky fan to stop running is to shut it off at the breaker or the Emergency Shut-off switch. Well, if you are going to have a problem with your heating or air conditioning system, this is the one to have! Although your fan never shuts off, your heating and air conditioning still works fine. And if you have allergies, it's better to have your fan running continuosly to filter more air anyway. And keep in mind, it really doesn't hurt the motor or cost more money, running all the time. And lastly, fixing this problem, usually isn't an expensive repair. But having said that, do not ignore the problem and let it linger, call for service. So What Causes This? Usually Only Three Things...

A fan relay that is stuck closed A shorted thermostat cable That is about all there is to this problem. So if your fan doesn't shut off, don't panic - just schedule a service call and have it repaired. The Blower motor on my AC unit turns off at random times while the outside unit continues to run which is causing the coil to freeze up. The blower won't come on for 30-45 minutes after the AC has been turned off, but after that it seems to turn back on fine. I have been trying to track the problem down for the last couple months, but it literally only happens every 2 or 3 weeks. Last night it stopped again and I tried to just turn the fan (from the thermostat) on without luck. I took a look at the blower and it seemed to turn just fine. I put my hand on the back of the fan motor and it wasn't hot to the touch. About 45 minutes after it turned off the blower came back and it was working normally. What could be causing this problem? I ended up calling a buddy of mine who is an HVAC tech and he pointed me in the right direction to check the fan wire on the back of the thermostat.

I checked the wire and it was just hanging in the terminal. I'm pretty sure that was the cause of the problem. It makes sense because there wasn't anything wrong with the blower motor itself. The fan wire on the thermostat was in fact the problem. I fixed the connection and it has worked fine for the last 3 years. I have a ruud rheem heat pump, I had this same issue. The unit was installed in 2006. After going through the typical steps of checking air filters and electrical components on the unit, I found the wiring from the thermostat for the blower control to the control board was rusted in the wire nut. I cut the wires and stripped them back and reconnected the wires and the AC unit is running with out any trouble now. Remember to keep it simple. HVAC service companies love these type of calls that an experienced tech can track down quickly. If you have a basic understanding of how circuits work you can fix this easily and save a bunch of cash. My central AC unit decided to stop on the hottest day of the year.

It would start and run normally for a few minutes and then the blower would shut off. After checking the breakers, thermostat and overflow shut off (did not have one) I saw something about a blower motor capacitor. This was easy to get to and replace and my last hope before waiting for someone to come fix it. The capacitor cost $4.04 with tax and had my AC working again. Needless to say I was beyond happy. ac unit uses waterI hope this can help others with a similar problem.window ac unit with no window Check your drain lines for water run off. window ac repair shopsMake sure they are clear and then check the float for the excess water shut down reset them Also check your ground. I just ran across an intermittent blower issue (cycling on and off constantly during call for heat from the thermostat) that was due to a poor ground connection on my 120 volt to 24 volt transformer on an old Janitrol furnace.

The ground side of the 24 volt half of the transformer had 2 wires connected to it. The good one went to the mounting screw of the transformer. The bad wire went to the circuit board. It was bent over perpendicular just above the connecter, and many of the strands were broken. There was also some minor corrosion. Replacing these ground connections resulted in satisfactory operation. This was difficult to troubleshoot because operation was okay if the air filter was not in place, and the issue showed up only when an air filter was installed on the supply side (dirty or clean filters both had the intermittent problem). Thank you for asking. Your thermostat 24V wire line is lose, interrupted, broken or oxidized. Solution : disconnect old 24V line, and run new line, if this restores your blower motor function the old one was defective. Thank you and have a nice day.Staying on top of your central air conditioner can save you big money on repair bills. Any number of small items can render your air conditioner inoperable.

Before calling a repair service, troubleshoot some of the common air conditioning issues that cause a unit to fail. You can fix many of these items on your own, without the help of an HVAC professional. Check the Thermostat Check your thermostat to begin your central air conditioning troubleshooting. Make sure the thermostat switch is in the "on" position, and it's set to "cool." If the thermostat is a digital model, replace the batteries if applicable. Verify the temperature setting on the thermostat is lower than your room’s current temperature. Many times, thermostat settings cause the trouble. If the inside unit fails to come on once you've checked the thermostat setting, check the fan switch. The fan switch should be set to "auto" and not "off." If the switch is set to "auto," move the switch to the "on" position. If the fan does not come on, check the circuit breakers. Replace the Air Filters Check the air filter inside your unit if it still doesn’t produce cool air. Pull out the filter and inspect both sides.

If the filter appears dirty and clogged, you must replace it. You should clean or replace your air filter once a month to keep the unit working properly. A clogged air filter will cause the unit to work harder, overheat and not cool as efficiently. Check the Circuit Breakers Your air conditioning unit has two breakers; one operates the outside unit while the other operates the inside. If the breakers appear tripped, turn the breakers off and then back on to reset them. If the unit comes on briefly once you reset the breakers, but they trip once again, call an air conditioning service provider to check the electrical wiring. Check the Condensate Drain If resetting the breakers turns the unit back on, but the unit still won’t cool, check the condensate drain line. A float-switch safety device sits inside the drain. Should the line clog, the float-switch turns off the unit. This stops the creation of condensate that could overflow, damaging the unit and your home. Attach a wet/dry vacuum to the condensate drain line outside your home to ensure it is free from clogs.

Check the condensate drain line inside your home while running the vacuum. You should hear air rushing through the line. This means the vacuum has removed all excess water and gunk built up inside the drain. Once you've completed the inside central air conditioning troubleshooting, check the outside unit. Check the Outside Safety Disconnect If the inside unit is operating, but the outside unit is not, check the disconnect switch on the exterior wall. This separate safety shut-off switch allows an air conditioning service provider to interrupt the power to the unit when making repairs. If the disconnect switch is in the "off" position, turn it on to see if the outside unit starts. If it doesn't start, check the switch fuses. Test the fuses with a continuity tester if you feel comfortable working with electricity; if not, you may need to call a professional. If the fuses are good, and the disconnect switch is in the "on" position, it may be the dual capacitor or the fan motor. Check the Outside Unit The outside unit requires both the fan motor and a dual capacitor to operate the condenser.