AC Repair: How to Troubleshoot and Fix an Air Conditioner

Air conditioners may experience a multitude of problems ranging from a lack of cooling efficiency, and blower motor problems to refrigerant leaks, and even warm air coming out of the AC. Repairs will cost you a considerable sum, which is why some homeowners with a penchant for DIYs take it upon themselves to repair their air conditioners themselves.

In this article, we present the step-by-step guide to AC repairs that you can do at home. Fix that malfunctioning air conditioner, and enjoy the cool air! Here's what you'll need to get your AC fixed at home:

What You'll Need

Power Drill
Screwdriver
Needle-nose Pliers - for replacements
Adjustable wrench - for replacements
Multimeter
Compressed Air
Replacement Parts - Capacitor, Compressor, Fan Motor, Fuses, etc.

Before Starting

Before you start, it is a good idea to know what you're getting into. Aircon repairs are hazardous, as they contain coolant which can be irritating to the skin and respiratory system when exposed to the gas. Dirty ACs will have all sorts of dust and allergens, including roach and rodent feces, which is harmful to the health.

We recommend wearing protective gear and clothing when attempting to repair your own air conditioner. Rubber gloves will protect against electric shocks, which may happen as you tinker through switches and wires of your AC unit. Glasses will protect from flying debris, and a mask should filter out potentially hazardous inhalants.

Step-by-step Guide

Step 1: Check the Error Code

First, check if your air conditioning unit is flashing an error code. Air conditioning systems often have a self-diagnosing feature that tells you exactly what the problem is. Identifying the error code will make it easier for you to troubleshoot and do an air conditioning repair as you won't need to do trial and error to figure out the problem.

Each AC system would have a different set of codes, which may be alphabetical, numerical, combination, or simply flashing lights. For a central air conditioner, the error code would be displayed on the LED screen of the control board instead of the unit. Wall-mounted AC systems may show their error code on the remote control.

Step 2: Cross-reference with Your Owner's Manual

Dig out your owner's manual and guidebook from when you first purchased and installed the air conditioner. Here, you will find sections for troubleshooting and repair as well as a list of error codes, including Mitsubishi aircon error codes, that you can use to cross-reference with the error code flashed on your AC system. Identify what the error code indicates before moving onto the next step.

Step 3: Turn Off Your Unit and Unplug it from the Socket

Now that you know the problem with your unit, turn off your unit, and unplug it from its socket before you do any sort of repair. For a central air conditioner, you may need to shut the power off from your main power switch for your own safety.

Step 4: Clean the AC Unit

Clean your unit by washing the filter with soap and water. Clean the evaporator coil with some compressed air, and do the same for the condenser coils. You may have to use a power drill or screwdriver to crack open the housing where the condenser is located. Do so with caution to prevent damaging the unit, and to prevent accidents.

You may use your garden hose to clean the condenser coil as it is part of the outdoor unit, which allows most parts to be washed with water. Use a steady stream, and avoid using the power wash mode on your garden hose when cleaning your AC unit.

Unclog the drain line by running water through it. Debris should flow right out of the drain, but if the debris is stuck, use a stick to gently nudge the blockage out.

Step 5: Test the Fuses

Check the disconnect blocks. You should find two cartridge fuses that would normally look bright and new. Any sign of a blown fuse would indicate a failing condenser, which you will need to replace before it completely falls apart.

Test the fuses using your multimeter on the lowest Ohms scale. Connect the red lead to one end of the fuse, and the black lead on the opposite end. You should see a numerical value on your multimeter indicating a working fuse. If there is no number, 0, or an infinity symbol (∞), you have a blown fuse that you need to replace.

Step 6: Inspect the Access Panel

Next, inspect the access panel which is located by the electrical conduit of your home. Use an insulated screwdriver to carefully remove each screw from the panel box, and take note of all the screws so you can place them back onto the proper sockets later on.

Check for any signs of damage: chewed wires from pests, rodent and roach nests, burnt or exposed wires, or broken electricity connectors. Clean and replace any broken parts as necessary. Discharge the capacitor, then work on rewiring the access panel. It is best to call one of our technicians at Luce Aircon for this if you have little experience with wiring.

Step 7: Replace Any Broken Parts

Replace any broken or faulty parts. Based on the error code from your air conditioning unit, you should have a guess at which part of your air conditioner has been damaged, worn down, or is faulty. Replace these parts to get your AC unit up and running again.

Step 6: Test The Result

Screw everything back into place, and plug your unit to power it on. Check if your repairs have fixed the issue, and if not, check for a different faulty component instead. When all else fails, contact one of our technicians at Luce SG for all your aircon maintenance and repair needs! We're sure to get to the bottom of the problem, and get you your air conditioning!

Repairing Air Conditioners by Brand

Price Range Guide

Service	Average Cost
Aircon General Cleaning	SGD40/Unit
Air Conditioner Chemical Overhaul	SGD150/Unit
Repairs for Refrigerant Leak	SGD750
Repairs for Aircon Fan Motor	SGD400 for Replacement
Repairs for Aircon Thermistor	SGD70 - SGD200
Repairs for Aircon Condenser	SGD700
Repairs for Aircon PCB	SGD350 - SGD900

Solve the Problem - The Hassle-free Way!

Repairing an aircon unit yourself requires some knowledge of the anatomy of HVAC systems across different models and brands. Repairing your own AC is highly dangerous, as you risk potentially damaging your unit, or injuring yourself through sharp parts or electrical shocks. Instead, repair your unit the hassle-free way: with Luce SG!

Our technicians are licensed to inspect, clean, and repair cooling systems across several brands, models, and types of ACs across Singapore. Not only will we find out the underlying problem for you, but we'll repair your AC unit to be as good as new!

Contact us today to schedule your AC repair!