Air Conditioner Repair Concord, CA; Top ten most common A/C problems

air conditioner not working

Jim Jones, 11-24-2020, Stars 5/5

No. 1 - Bad Capacitor
The top 10 most common air conditioner problems in Concord, CA. Coming in with an overwhelming first place is a bad capacitor; when the capacitor goes bad, it'll bulge out on the top. Sometimes it's rare, but sometimes the whole top will pop off, and you'll have that dielectric grease all over your electrical section.

There are other times when the capacitor looks good. However, it's still dead, and the only way to check that is to use a meter, or you can blindly replace it because that is the most common fix. Over time capacitors die, that's normal, but their death is sped up by a filthy condenser coil. It would be best if you cleaned that frequently.

No. 2 -Low On Freon
The second most common problem is the air conditioning unit is low on refrigerant or freon. Here's something you should understand that an A/C system is a permanently sealed system meaning whatever freon is in there stays in there for the unit's life. It's not like gasoline where you pour some in occasionally, so if some is missing, that guarantees the leak is somewhere either the outside unit or the coil that's on top of your furnace or the line set in-between or at one of the braze joints.

You could call a technician and get your freon refilled but keep in mind that it will inevitably leak back out with time. Usually, it only lasts one season because it's a pressurized system, so even during the winter, it slowly leaks out.

Eighty percent of the time, the leak is found in the coil, on top of the furnace, and typically cannot be repaired. You have to replace the whole coil because the solder joints are so close to each other when you start melting one of them; the one right next to it melts as well.

Replacing the coil is expensive, so most people spend a couple of hundred bucks every year refilling it, or they replace the whole thing altogether. Often when you're low on freon, the coil that's inside on top of the furnace will freeze over. Suppose you come outside and see your suction line frozen and look inside. You see your compressor frozen, which means that the coil on top of the furnace is just a solid block of ice because it starts freezing up from inside and then goes outside.

If you see a lot of ice, you might as well turn your A/C off because it's not doing much cooling anyway; just set it to off and turn your fan from automatic to on so the fan inside of the furnace will keep running to thaw that ice out. When that block of ice does melt, a lot of it will run down the sides of your furnace, and it'll pull up on the bottom like you have a big leak coming from your furnace.

It might be a good idea to put some towels around it. If you have some boxes or carpeting around your furnace, you might want to move those away when you turn the fan on to defrost the ice because there will be a lot of water coming down.

No. 3 - Clogged Condensate Drain
The third most common is a clogged condensate drain. If you're finding water leaking all over the furnace, but the air conditioner is working correctly, sometimes the culprit is the hose coming from the drain fitting on the A/C evaporator coil sitting on top of the furnace.

Most of the time, it'll be the fitting that's plugged up, and you can either blow that through or take the hose off and take the fitting off and clean it all out. Chemical tablets can be another alternative; also, installing a larger hose will help.

No. 4- Bad Control Board
Fourth place is a bad control board. A common problem with the control board is that it's not sending power to the outside unit when the thermostat calls for cooling. Sometimes, it'll be doing wacky stuff like turning on the furnace at the same time the air conditioner is running. It could have a bad fan relay on it, so it's not sending power to the blower motor, so the A/C turns on, but the blower motor and the furnace does not.

When that happens, there's no airflow. Your coil that's on top of the furnace will freeze over in like a minute, and the longer you run it, the thicker that ice layer will be on that coil and the longer it will take to thaw that thing back out. The fix for that is replacing the control board.

No. 5 - Burnt-Out Condenser Fan Motor
Coming in at fifth place is a burnt-out condenser fan motor. So what that will look like usually after the air conditioner is turned on is the compressor will start running, but the fan will not. Eventually, you'll feel a lot of hot air coming out because that compressor is overheating, and it'll probably trip a breaker.

Usually, if you take a screwdriver and try to spin that fan blade, you will notice that it's really stuck, and it does not spin freely. You can try to take the motor out and oil it, but oiling it does not do much good from what I've seen in the past. In like a week or two, it will cease back up again. So the fix for that is replacing the whole motor. Generally, when we replace the motor, we always replace the capacitor as well.

No. 6 - Burnt-Out Blower Motor
In sixth place is a burnt-out blower motor inside the furnace; that one's pretty simple many times because it'll smell like a burnt electrical smell. Take out the bottom door of your furnace and reach in there and try to spin that blower wheel. Usually, it'll be all seized up, or it's humming, and if you give it a spin, it'll turn on. What that means is that the capacitor for that blower motor is dead. You can replace that capacitor and get it to work. Still, a lot of times, it only lasts like two weeks because the blower motor is burnt generally if the capacitor is entirely dead for a blower motor. In that case, we replace the motor because it doesn't have much life left in it.

No. 7 - Compressor Shorting Out
Coming in seventh place is a compressor that has been shorted to ground. Usually, the air conditioner circuit breaker keeps tripping, so you go to the breaker and reset it, turn the AC on, and bam, right away, it trips the breaker again.

My next step is to check for any broken or burnt wiring and then take the top off, take the wire connectors off of the compressor pins, and then check those compressor pins to the actual casing of the compressor to see if the windings are shorted to the case of that compressor. If they are, then the compressor is shot and needs to be replaced; that is also a costly repair, so many people choose to get a new unit.

No. 8 - Dirty Furnace Filter
A filter is a very easy thing to forget about. Concord residents forget about them for a long time, like a year or two. When you pull that filter out, it's like black. When airflow is restricted that much, it's like the blower motor isn't even running, so the coil on top of the furnace will freeze over. So don't forget to change your furnace filters regularly. The worst one I've seen was so plugged that the blower motor sucked the whole filter in and got wrapped all-around the shaft and was hard prying that filter off.

And by the way, the filters are directional; usually, there's an arrow on the filter that says airflow "this way" that arrow should be pointing towards the furnace or the blower motor because usually, that side will have a net on it to prevent it from being sucked down.

When people ask us what the best filter to use is, our general recommendation is a medium grade pleated filter. the premium accordion types are too closely knit together and tend to be a little too restrictive; also, the ones that are fiberglass, either blue or green they tend to let everything through, so a technicians choice is a medium grade pleated filter

No. 9 - Dirty Condenser Coil
The air conditioning unit is not cooling the house well, or the breaker keeps tripping. After inspecting the coil, there'll be half an inch to an inch of leaves and whatever else is plastering the coil. Usually, the coil's dirtiest side will be the one closest to the house because that's where it sucks in most air. To clean that, all you need is a water hose. The best way is to take the top off and spray it from the inside out but from what I've seen, spraying it from the outside gets the job done almost as well.

No. 10 - Bad Contactor
The contactor is the electrical switch that closes the circuit to allow your system's power when you set your thermostat to cool or heat your home. Usually, when the contactor is bad, it'll be something obvious where half of it is melted off, or when you look at the coil, it's all warped. Sometimes the contractor will have no visible damage but will make a humming or chattering sound. If the contactor's points are dirty or corroded, you can spray them with some contact cleaner. Other than that, it's best to replace it with a new one.

AC Repair Team offers expert air conditioning repair, tune-ups, air quality checks and maintenance. Give us a call to set up an appointment at (925) 808-3141.