DIY Air Conditioner Repair

Your air conditioner is a very important installation in your home. It helps maintain a comfortable indoor temperature and the indoor air quality too. It’s normal for us to get flustered and stressed when something goes wrong with our HVAC system and in most cases, we simply call in a professional to inspect the system and fix the problem. While that is always the best approach, there are some basic air conditioner repairs you can easily handle yourself.

DIY AC Repair Tips

All you need are some tools; an understanding about the things that can go wrong and what the standard troubleshooting steps are. Here is a guide on DIY air conditioning repair. Following these can help you save some money on a service call and the associated expenses. Here we talk about common “no cooling” and “low cooling” issues.

Central AC Systems- the failures and how to fix them

If your replacement AC fails, and are comfortable with doing a few basic repairs and are okay with spending under $100 or less on any spares you may require, all it will take you is a couple of hours to fix your air conditioner. The steps to follow are:

1. Ensure the problem isn’t due to the furnace

    Set the thermostat into A/C mode & then reduce the temperature setting. If the furnace’s fan starts up the problem doesn’t lie there. However if the fan doesn’t kick-in, you should try to re-set the furnace’s circuit breaker. If that doesn’t work, you’d have to call in a professional to fix the system.

2. Check the condensing unit located outdoors

The fan and the compressor (that sounds very much like a refrigerator) should be running. If it isn’t, go through these steps:

    Turn off the system’s power at the main electrical panel. Use a voltage tester on the wires coming into the contactor to make sure the power is really off. The start/run capacitor & contactor (relay) are the ones that fail most commonly and are quite inexpensive to replace. If your wholesale air conditioner is over 5 years old, it’s a good idea to simply replace these components. While the condenser’s fan motor can fail as well, it can cost up to $150, so it’s best to defer purchasing it unless you are sure it’s the real culprit. Ensure you are buying compatible parts based on the model and make of AC unit you have.

3. Other checks for no cold air/little cold air problems

    • Look for the electrical box adjacent to the AC condensing unit; pull & disconnect its block. Use a voltage sniffer to ensure there is no current in it. Ensure that all the registers within the house are fully open. Make sure the furnace filter is completely clean. Go outside and thoroughly clean the

condenser coil

    s. If many registers were shut or if the filter had gotten clogged with dirt and debris, the reduced flow of air can cause the coil to get iced-up; this can impact the cooling in your home. If you’ve replaced the filter & ensured that all the registers are open, but still can get any air-flow started, you would have to de-ice the system’s A-coil. Change the thermostat’s mode switch from the “Cooling” function to the “Off” position and turn the fan’s switch from the “Auto” function to “On.” Next, allow the blower to run for a minimum of 30 minutes or until the point you detect a good airflow at all the registers. Then turn the air conditioner back on and test it. If it works consistently and without problems for the following 12 hours, you’ve solved the unit’s problem.

Condenser coil fixes

    • Clean the

condenser coil

    • s (even if you find they are already clean). Now turn off the power. Turn the furnace and A/C’s circuit breakers in the main electrical panel into the “Off” position. Turn off the main power switch located in the air-handler/furnace. Yank the disconnect block out & clean the

condenser coil


If the unit still doesn’t function well after you’ve thoroughly cleaned the condenser coils, replaced the filter & opened all the registers, these are the steps to follow:

    Test the fuses located in the disconnect block. When you use the millimeter multimeter, a zero/ infinity symbol (∞)/ minus symbol indicates a blown fuse. Some disconnect blocks have 2 cartridge fuses. Check these before you proceed with any repairs. A blown fuse is typically a sign of some failing part within the condensing unit

Don’t simply replace it and sit pretty thinking the problem’s been solved. Instead, replace the components mentioned below. After that install new fuses and start-up the unit; if the fuse blows again, you would have to call in a professional, as the issue is too severe for you to handle.

Before you replace any of the components, check for evidence of chewing on electrical connectors/wires and for rodents’ nests.

    If you find any chewed insulation or broken wires or can safely handle basic electrical repairs, first discharge the capacitor first. Repair the wires & then clean out the rodent’s nest. Replace the start/run capacitor(s) Replace the air conditioner contactor

4. Replace the Fan Motor

The final DIY air conditioner repair that might be required to fix the system is a fan motor replacement. The steps to follow are:

    • Mark the blade to indicate which side is up. Next loosen the fan blade’s setscrew. Carefully pull it off the motor’s shaft. Swap in the new motor. The motor wires should be routed through the older conduit and secured with zip ties where required. Affix zip ties or the fan blade could sever the wires. Reinstall the disconnect block and access panel. Turn on the system’s circuit breaker & the furnace switch. Set the thermostat to a much lower temperature and then wait for the A/C to start. The


    •  should start & the condenser’s fan should spin. If you find that the


     runs but the fan doesn’t, the latter’s motor is most likely shot. Turn off the power & remove the condenser cover screws. Lift the cover & remove the motor and the fan blade and motor. Now, reinstall the blade & then secure the cover. Repower the system and see if the fan runs (they have a built –in delay function and it can take up to 10 minutes after you have restarted the system for the thermostat to get started up)

If the wholesale AC still doesn’t start up, you would have to call in a technician to handle the job.