Air conditioning is a crucial part of any home, especially during the hot summer months. However, like any mechanical system, your air conditioning unit can break down or stop working efficiently, leaving you in need of costly repairs. Fortunately, there are some simple DIY air conditioning service and repair tasks you can perform to keep your AC running smoothly and save money on repairs.
Troubleshooting Common AC Problems
If your air conditioner is not cooling your house, there are a few things you can check before calling in a professional. First, make sure the problem isn't in the furnace. Set your thermostat to AC mode and lower the temperature setting. If the furnace fan kicks in, the problem isn't in the furnace. If the fan doesn't run, try resetting the furnace circuit breaker. If the fan still won't start, call a pro—the fixes shown here won't work.
Next, check the outside condensing unit. The compressor (which sounds like a refrigerator) and fan should be running. If not, follow the troubleshooting and repair procedures shown below.
Caution: Turn off the power. Turn off the A/C and furnace breakers in the main electrical panel before pulling the outdoor disconnect or removing the condensing unit's access panel. Then use a voltage tester on the wires coming into the contactor to make sure the power is really off.
AC Service and Repair Parts
The AC contactor (relay) and start/run capacitor(s) fail most often and are inexpensive. So it's a safe bet to buy and install those parts right away, especially if your air conditioning service unit is older than five years. The condenser fan motor can also fail, but it runs about $150—hold off buying that unless you're sure that's the culprit.
To buy replacement parts, find the nameplate on the condensing unit (not your furnace). Jot down the make, model, and serial number (or take a photo). Get the parts at an appliance store, furnace dealer, or online.
Anatomy of a Central Home Air Conditioner
Central home air conditioner service systems consist of two major components: a condenser that sits outside your house and the evaporator coil (often referred to as an A-coil) that sits in the plenum of your furnace or air handler. The refrigerant in the A-coil picks up the heat from your home and moves it to the outdoor condensing unit. The condensing unit fan blows outside air through the condensing coil to remove the heat. The condensing unit houses the three parts replaceable by a DIYer: the AC contactor, the start/run capacitor(s), and the condenser fan motor. The condensing unit also houses the compressor, but only a pro can replace that. The A-coil has no parts that can be serviced by a DIYer.
Shut off the power. Open the electrical box next to the condensing unit and pull the disconnect block straight out. Check inside the box with a voltage sniffer to make sure the power is really off.
Cleaning the Condenser Coils
It's really easy to clean an air conditioner condenser, and it's one of the regular maintenance tasks that will extend the life of your unit. First, turn off the power to the unit. Then:
- Aim your garden nozzle upward into the top of the condenser coil to remove the crud buildup under the lid.
- Work all the way around the coil. Then aim the nozzle down and flush the debris down the coil fins.
- Adjust the nozzle to a gentler stream and shoot water directly into the coils to flush out any remaining debris.
Testing the Fuses
Many disconnect blocks contain two cartridge fuses. Check them before you proceed with repairs. A blown fuse is a sign of a failing part inside the condensing unit. So don't just replace it and think you've solved the problem. Instead, replace the parts, install new fuses, and fire up the unit. If it blows again, call a pro—you may have a more serious issue.
When to Call a Professional
While some air conditioning repairs can be done by a DIYer, others should be left to a professional. For example, if your AC unit is making unusual noises, emitting strange odors, or not cooling effectively even after performing the DIY service and repair tasks mentioned above, it's time to call in a professional. Additionally, working with electrical components can be dangerous, so it's important to follow safety precautions and turn off the power before working on your air conditioning system. Finally, regular maintenance and inspections by a professional can help prevent breakdowns and extend the life of your HVAC system.
Conclusion
By following these DIY air conditioning service and repair tips, you can keep your AC running smoothly and avoid costly repairs. Regular maintenance and cleaning of the condenser coils, testing the fuses, and replacing common parts such as the AC contactor and start/run capacitor can all help prolong the life of your air conditioning unit. However, it's important to know when to call in a professional for more complex repairs or issues that cannot be resolved with DIY service and repair.
Remember to always follow safety precautions when working with electrical components and turn off the power before attempting any repairs. With a little bit of knowledge and effort, you can keep your air conditioning system running efficiently and ensure your home stays cool and comfortable all summer long.