Air Conditioning • HVAC A central air-conditioner is an elaborate system that involves parts such as an evaporator, a compressor, a condenser, fans, and refrigerant to run through the unit. Like many household appliances, each of these components does their job both independently, but also in unison with the connecting parts and when one section of the system goes down, the entire performance falters. While each component in a central air-conditioner is critical, quite simply the unit will not work if the fan is not running. Fans in the central A/C both pull air out of the room to be conditioned and have humidity removed and also push chilled air through the vents throughout the house. When the fan goes down there is no way to cycle the air and thus the system is essentially stalled. It’s important to get the fan up and running ASAP or else the home will get uncomfortable in a hurry and you could end up damaging the compressor. There are a few ways to tell if your A/C fan is temporarily or permanently out of order.

The first is an inspection of the outdoor unit to physically see if the fan is turning. The condenser lines should be cold and the air inside the home should be cool. how do i know what size ac unit i needIf the fan isn’t running at all or there is warm air blowing it’s time to troubleshoot:first ac unit in a car If the fan doesn’t start up at all it could be something as simple as a setting on the thermostat. best ac window unit 2013Make sure that the power is turned on and that the settings are calling for ‘cooling’. If all the settings are correct but the fan doesn’t start it could be an overheated or damaged fan motor. In some cases, you can give the fan a ‘kick start’ by pushing it with a stick and if this occurs there is likely an issue with the capacitor.

Similarly, if a fan won’t turn when the power is on but will rotate freely when shut off it could be the sign of a bad motor bearing. Trouble with the bearing will also result in wobbly or lopsided turning if the fan does run. The fan needs to run at an optimal speed for the system to function properly. If the blade turns noticeably slower there may be low voltage running to the unit caused by issues with the control board or problems with the circuits. Also, the fan blade may have come loose from the motor shaft and is simply moving slowly because of a breeze or the turning of the shaft. Once again a capacitor may also be causing issues with the slow moving fan. If your Central A/C fan is acting unpredictably, starting on and off at random and shutting down in the middle of a cycle it could be a sign there’s an issue with the wiring or some loose components somewhere. It’s normal for a fan to keep running for a short time after an A/C cycle while the compressor motor stops but a fan that keeps winding excessively there are likely problems in the circuit board or with the wiring.

As long as the A/C unit is running properly some homeowners may be willing to ignore a ticking, rattling, or buzzing coming from the fan area. In reality, it’s best to diagnose these sounds to make sure they aren’t leading to serious problems down the line. The first thing to check is that an obstruction isn’t hitting the fan blades as they turn or that the blades aren’t bent. Buzzing and humming are somewhat more sinister as they could present a problem with the motor or the bearings turning the blades. The common denominator with all these problems is that, although a visual inspection might locate the problem, the fix should almost always be done by a professional HVAC technician. It’s better to spend money for a service call and be guaranteed you fix the problem rather than buy unnecessary parts or do incomplete fixes that could end up costing more in the long run. Are you in Pennsylvania and need help with your HVAC system? Contact us today for a free quote!

Is the thermostat the problem? When we have our central air fan set to "on," it runs fine, but when we set it to "auto," the fan does not come on even though the AC compressor kicks in.  (The AC unit is working fine...It comes on and produces cool air). This means that we have to keep the fan on constantly when we want the AC on.  Do we need to replace the thermostat? It didn't seem to have this problem throughout the winter when we had the heat on and the fan set to "auto." Ultimately, you may have to replace the thermostat. But before you do, try these steps: 1) Thermostat switches make electrical contact across two very small conductors that carry a very low energy signal. This means a low-energy battery, without enough energy to create the required signal, can result in problems like you're experiencing. First step ... purchase a fresh battery and replace the old one. Move the temperature and fan switches to the "Off" position and then return to your preferred settings.

Allow several minutes for the thermostat to "cycle." Then determine if the compressor and fan have come on; 2) Because the thermostat conductors are very small, if the switches are slightly out of position and they will not conduct the required energy to transmit a signal to the fan and compressor. Try simply wiggling the switch back and forth gently across the "Auto" position and allow it to stop as you feel it click into the "Auto" position. Allow several minutes for the thermostat to "cycle" and determine if the compressor and fan have come on. These are two easy steps that may allow your system to work. Since you report the thermostat working fine in the "Heat" position, I would expect it to work just as well in the "Cool" position. I hope one of these simple fixes works! However, if these steps do not work, thermostats are relatively inexpensive and the included instructions make it fairly easy to install. Make certain you purchase a thermostat for the type system you have (ex. heat pumps often take a different thermostat that compressor systems).

Then, pay attention as you remove the old thermostat and reinstall the new thermostat following the color codes on the instructions. Finally, if none of these steps work, have a reputable licensed AC contractor service the unit. Most units that are serviced regularly provide efficient service for many years. I have taken these steps many times in the transition between heating and cooling seasons, and I'm always pleased that I didn't turn a small repair into an unnecessary, much larger repair bill. NOTE: This is a great time to change your air filter. Check the size and purchase a replacement while you're at The Home Depot. A Plumbing Associate will be happy to discuss your options. Relays/capacitors are commonly damaged by power surge ... lightning is a common enemy of this part! The visible indicator is the canister swells like it wants to burst. Relays are beyond most DIYer's desire or ability, so I didn't include it in my earlier list. If you were able to identify the item, a local A/C supply house would likely stock the part and may or may not sell it to you ... some require licensure to sell any of their parts while others will sell non-regulated supplies to anyone.

Unless you are particularly handy with electrical, I would save my resources for that reputable, licensed repair shop. You may find the solution another way, but having your annual service and including this repair is likely a good idea. I really like to "Fix It" when I can, but there are times when you just have to let go and call a pro! This may be one of those times. A Quick Warning: "Start Relays/capacitors" build up energy and discharge that energy to help start electric motors. This discharge can give you a very real shock!!! Be very cautious if you decide to proceed on your own. You are soo welcome, Jennie! When you resolve the problem, take time to come back and explain what you found and how you resolved the problem. I'm certain you'll be adding very useful information to the body of knowledge here on The Community. I have a Carrier Gas Furnace and a Hunter Fan Thermostat 41110. The thermostat will not let me set date or time and/or move button up and down to set temperature.