Blocked filters are one of the most common problems we find when responding to domestic air conditioner faults. With standard washable filters, a yearly clean is a minimum to ensure the correct operation of your air conditioner.

If you find the filters are caked in dust and dirt every time they are cleaned, it would be worth doing 3-6 monthly. We recommend cleaning your air conditioner filters before Summer and Winter to ensure they will not cause your air conditioner to run inefficiently.

If your air conditioner faults or just stops working, it may have faulted on a safety lockout. These are designed to prevent irreversible damage to the unit if operating incorrectly. Although it is best to get your unit checked by a professional if your air conditioning unit faults, resetting the unit may rectify small issues such as a power failure fault or overtemperature fault. To reset the unit, simply find the air con or a/c circuit breaker in the fuse box and switch it off. Leave this off for 5 minutes and then switch the circuit breaker back on. Return to the control panel and switch the air conditioner back on.

If the problem recurs soon after resetting, record the fault displayed on the controller (if visible) and call the specialist air conditioning technician in your area. If you are not sure who specialises in your brand, contact the manufacturer and ask for their approved service provider in your local area.

A common cause of noisy ducted air conditioner operation is due to a blocked return air filter. If the filter is blocked, air will struggle to pass through creating noise during operation. Another common problem is the grille not fitting properly allowing air to bypass the grille and ’whistle’ when the fan is running. First, clean the filter with a hose and allow it to dry. Second, install the filter back into the grille and ensure it is centred to prevent air gaps which can cause the filter to whistle.

Noisy indoor units can also be caused due to incorrect sizing of the return air grille for the unit. Ensuring the return air grille is large enough to allow the correct amount airflow is important to keep noise levels low during operation. With an undersized return air grille, your air conditioner will be ‘sucking’ harder than it should and cause the unit to become noisy. This is exaggerated when the filter becomes blocked.

If the noise from your air conditioner is a banging or grinding noise, turn it off immediately. There is a good chance the indoor fan motor or fan motor mounts have failed and a qualified technician will need to attend and rectify the fault. Call the specialist air conditioning technician in your area for assistance. If you are not sure who specialises in your brand, contact the manufacturer and ask for their approved service provider in your local area.

Melted fan motor mount

During the cooling cycle, most air conditioning units will blow air the entire time the unit is operating. During the heating cycle, this is not the case as the unit shuts the fan off when heat is not required. If your unit is only blowing air and it is not cold, ensure you have the unit set to ‘cooling’ mode on your controller. This is generally shown as a snowflake symbol or the words ‘cool’ or ‘cold’. If your controller is set to cooling then ensure the temperature is set low enough so the air conditioning unit knows you want it to cool, on a hot day 16℃ is low enough to test operation. If the unit is still not producing cold air, try resetting the entire air conditioning system by switching off the power for 5 minutes at the fuse box.

If the problem recurs soon after resetting, record the fault displayed on the controller (if visible) and call the specialist air conditioning technician in your area. If you are not sure who specialises in your brand, contact the manufacturer of your air conditioning product and ask for their approved service provider in your local area.

During the heating cycle, most domestic air conditioning units are designed to shut off the indoor fan operation when heat is no longer required. For example, if the air conditioner is set to 25℃ and the temperature in the room is 27℃, the a/c unit does not require any heating and the indoor fan should stop. If the fan is still operating, you will feel a cold breeze coming from your air conditioning vents. Here are a few reasons for this happening listed below:

1 – During the defrost cycle, your air conditioning unit will switch to ‘cooling’ to allow the outdoor unit to heat up and defrost. If the unit is set up correctly, the indoor fan should not operate during this cycle. If your indoor fan is still operational during a defrost cycle, there may be settings within the controller that prevent the fan motor from shutting down correctly. Consult the manual for setting options or contact the manufacturer to get the details of your local repair specialist.

2 – If the fan speed setting is set to constant, the indoor fan will operate regardless of the mode of operation or room temperature. On some air conditioning controllers, you can set the fan motor to constant operation (instead of the ac unit determining when to run the fan). This means the fan motor will blow air regardless of the temperature, mode setting or defrost cycle. Ensure the fan setting on your controller is not set to constant, especially with a HanL-62 style controller common on Temperzone or Bradway a/c units.

Steam from your outdoor unit is pretty common during winter when your air conditioner is set to ‘heating’. The steam you can see is from the defrost cycle which is the frozen condensation melting and evaporating to the atmosphere. This is necessary to ensure the outdoor unit doesn’t freeze into a block of ice and prevent airflow over the radiator coil. If the steam smells like burning plastic or rubber, switch off the air conditioning unit immediately and contact your local specialist to investigate the cause. If you are not sure who specialises in your brand, contact the manufacturer and ask for their approved service provider in your local area.

Refrigerated air conditioning units are designed to remove moisture from the air on both the heating and cooling cycles. On the heating cycle, your air conditioner will draw moisture from the outdoor air and on the cooling cycle it will draw moisture from the inside air. When operating your air conditioner on heating, water will be visible on the ground near your outdoor unit unless the unit has been drained to a downpipe or garden bed. During the cooling operation in Summer, the water is drained out from the roof space and generally drains into the gutters.

Most air conditioning systems use similar shapes and logos to show which operation you have set. The Snowflake is the most widely used symbol for Cooling.

Think Snow → Cold → Cooling!

The universal setting for Heating is the sun. Although some controllers have a pretty poor picture of the sun, generally it’s a circle with dashes around the outside.

Think Sun → Hot → Heating!

Dry operation setting on your air conditioning controller (the drip symbol) is not often used in Adelaide, South Australia. Adelaide is mostly dry during Summer and does not suffer high humidity like our friends in the North. The dry setting on your air conditioner is designed to remove moisture from the air without lowering the room temperature. This setting will allow the unit to run on cooling but will limit the fan speed to a minimum, helping to keep the temperature from dropping too much. If you have a very humid day, the dry mode may be useful but generally, the cooling mode will be required as it removes moisture and drops the room temperature.

Temperature is a very personal preference! Everyone is different and it is often difficult to find the right temperature to please everyone. Generally, women require a higher room temperature whereas men like it slightly cooler (nothing sexist here, just observations!). The industry standard is 22℃ and around 50% humidity and this is what we try to achieve in commercial applications. In your own home, it is really up to personal preference. If your air conditioner is correctly sized and the airflow is balanced properly, it should be easy to experiment with the temperature setting of your ducted air conditioning system. Start by setting your air conditioner to 23℃ and let it run for an afternoon. If you find it is too hot, drop the temperature down to 21℃ and see how you feel. If it becomes too cold, set the temperature up to 22℃ and you may’ve just found your ideal temperature. Once you find your ideal comfort level write it down for next year.

The other factor to remember is energy consumption and cost. The lower the temperature is set on cooling, say 16℃, the more your air conditioning system will cost to operate. In the same fashion, if you run your air conditioner on heating at 30℃ it will also chew through your power bill. 28℃ is a lot more pleasant than 45℃ at the end of the day…. And will save a few dollars!