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. www.portable air conditioning unitThe unit was installed in 2006.how much is a 2 ton ac unit installed 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. average cost of a 2 ton ac unitI 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. I hope this can help others with a similar problem. Check your drain lines for water run off. Make 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.Common Air Conditioning Problems Common Air Conditioning Problems Air conditioners can fail at any time without warning.

If you live in a climate that’s as hot and humid as Atlanta’s, you are asking a lot of your air conditioner!  You probably know since living in this warm climate that any air conditioner outages can result in significant discomfort rather quickly. Many air conditioning problems are a result of insufficient maintenance.  The easiest repair is one that’s avoided altogether by keeping up on regular maintenance check-ups.  In fact, if you haven’t been keeping up on your maintenance and notice your air conditioner starting to slack, a maintenance check-up may be just what you need to get your air conditioner back up to speed.  Some common problems homeowners experience that go beyond regular maintenance and should have checked out include: the compressor failing to turn on, the air not coming out cool enough, low airflow, and leaks. Below are some ways you can diagnose air conditioning problems, descriptions of some common problems your air conditioning system may experience, and some special issues you should know about the refrigerant (freon) in your system.

Ways to diagnose a problem: Check fuse box or circuit breaker.  First thing to do if your air conditioner is not functioning properly is to check the fuse box or circuit breaker that services the unit.  The fuse may need to be replaced or the circuit breaker reset. Air conditioner turns on and off frequently.  The compressor and fan controls may be worn out. Unit turning on but not cooling.  If your unit is turning on, but the air isn’t cooling efficiently, your refrigerant may be low.  You may also need to clean off the evaporator or condenser coils by brushing them off or vacuuming them.  In addition, the filter may need to be replaced.  Clogged, dirty filters block normal airflow and reduce a system’s efficiency considerably.Dirty air filters and/or closed or obstructed supply-air and return-air grilles may cause insufficient airflow through your system.These are usually associated with low refrigerant or a clogged drain pipe.  Clogs can be fixed by clearing out the clogged pipe within the evaporator coil pan. 

Leaks should always be handled by a professional HVAC contractor. Common air conditioning problems:If your air conditioner is low on refrigerant, either it was undercharged at installation or it leaks.  If it leaks, simply adding refrigerant is not a solution.  A trained AC technician should fix any leak, test the repair and then charge the system with the correct amount of refrigerant.  Remember that the performance and efficiency of your air conditioner is greatest when the refrigerant charge exactly matches the manufacturer’s specification, and is neither undercharged nor overcharged.  In addition, refrigerant leaks can be harmful to the environment.If you allow filters and air conditioning coils to become dirty, the air conditioner will not work properly, and the compressor or fans are likely to fail prematurely. Electronic Controls and Sensors Failure.  The electronic controls and sensor that cause your air conditioner, fan and condenser to kick off and on properly are often the first components to go. 

Sometimes these sensors are merely knocked out of position causing the air conditioner to cycle constantly or behave erratically.  Fortunately, problems of this nature are easy to address compared to larger mechanical failures, and won’t cost you nearly as much. Fan and Condenser Failure.  Fan and condenser failure, on the other hand, can add up to some pretty pricey repairs.  Replacing burnt-out fan motors is usually worth the expense in order to get your air conditioner up and running again, though a failed condenser can be a different story.  A new condenser is the most expensive AC repair in the books, and depending on the age and efficiency of your current air conditioner, it might be a smarter investment to just upgrade to a newer unit. Special Note About Air Conditioner Refrigerant (Freon): Contrary to popular belief, air conditioners do not consume refrigerant (freon) as a car consumes oil, so under ideal conditions it would never need changing or filling.  Therefore, a low freon level indicates a leak which should be repaired before adding more. 

While most new system connections are welded to minimize leaks, many older units (8+ years) were connected with mechanical flared fittings, which can vibrate loose over the years, causing leaks. Problems with freon leaks: Low freon levels reduce efficiency of the air conditioner. They can freeze the evaporator coil, causing it to literally ice up. Freon is an Environmental Protection Agency (EPA) controlled substance, deemed hazardous if released into the environment. The heart of the unit is the compressor, which is cooled by the refrigerant.  Over time, low freon levels can cause overheating and premature failure of the compressor, often requiring complete replacement of the compressor or the entire condensing unit.  As mentioned earlier this is a very expensive proposition. Always contact a HVAC professional when dealing with refrigerant (freon). Join our email newsletter Get up-to-date current news, promotions and industry tips. Didn't find what you're looking for?