What’s That Noise? Troubleshooting Your Central Air Conditioner

If your central A/C isn’t working as it should, it’s important to get it dealt with as soon as possible. Waiting too long when you know the system is not performing can lead to other, more expensive problems very quickly.

However, before you pick up the phone to make that service call, there are a few things you can try to see if you can resolve the matter yourself. Sometimes, it is a simple matter of changing a setting or something similar and you might be able to save yourself some money on that service call – and get the problem handled more quickly.

Here is a checklist to help you troubleshoot some of the most common central air conditioning problems:

If your central A/C does not work at all:

1.    Check that the unit is getting power

Check your breaker panel and reset the system’s switches to see if it comes on. Sometimes a power surge will flip your breakers and it’s a simple task to get it going again. Keep in mind that your unit outdoors has its own breaker and switch separate from your main home panel.

2.    Check your thermostat settings

Be sure that your thermostat is set to a couple of degrees below the ambient temperature. If it is set even a degree above, the unit will not come on.

3.    Check the condensate float switch and pump

A/C units have a drain pipe which, when it gets clogged, will activate the float switch and shut off the unit. This will also happen if the drain tube has come apart from the pump. If this is the case, reattach the pipe, clear the drain, and try to restart the unit.

If your fan is running but the system is not cooling, it could be due to a number of things:

The condenser is dirty or blocked

Check the condition of the condenser. Clean the coil and clean and straighten the fins, if needed. If there is anything blocking the condenser, like leaves, weeds or debris, remove them. If your unit still isn’t cooling, your compressor may be faulty. In this case, you will need to call an HVAC technician

Unit needs refrigerant

Another common reason that a central air system ceases to work is a lack of refrigerant. This is another case where you will want to call a professional – do not attempt to do this yourself as you run the risk of damaging the equipment.

If your central A/C unit turns on and off repeatedly and is not maintaining the temperature in your home:

Check the condenser. It could be blocked or dirty – in which case, unblocking it and cleaning the coils and fins may help. Remove any debris that may be blocking the condenser.

Your evaporator may also be dirty. If you know where it is and it is accessible, you can attempt to clean it yourself. However, on some systems, the evaporator is more difficult to access. In this case, you will want to call an HVAC specialist.

These are the most common reasons your central air conditioning may not be working as it should. To keep your systems working in tip-top shape, seasonal, twice-yearly maintenance is always recommended. This will ensure you always stay cool when the weather is hot and that you get the maximum value from your home comfort investment.