How to know it is time to replace your air conditioner

Why air conditioners wear out

An air conditioner has a working life like any other appliance. A regularly serviced system usually lasts longer, but how long depends on the unit itself, the climate where you live and how often you run it. Some wear is normal even on a well maintained system.

Systems that are only switched on when the weather turns hot and never serviced tend to go past the point where a repair makes sense. Regular servicing puts that off. Our guide to what a service should include covers the basics.

The signs below are the common ones. If several of them sound familiar, it is worth pricing a replacement before the system fails on a hot day.

It no longer holds the set temperature

Older systems often keep pushing out air at the usual rate, but the air is not as cold or as warm as the setting asks for. You might feel warm air on a cool setting, or cool air on a warm setting.

Sometimes this comes down to low refrigerant. Warm air on a cool setting more often points to something more serious, such as a damaged compressor.

Inconsistent temperatures are a sign the system is on the way out. You can check the filters, drains and coils for anything blocking airflow, but if the problem persists a new system will stop the energy loss and bring running costs down.

Weak airflow from the vents

Little or no cool air coming from the vents while the system is running is a sign that the compressor may be failing. If the house is uncomfortably hot and a running system cannot bring the temperature down, it is not working as it should.

Check the filters first. A blocked filter is the cheapest fix there is, and our filters guide explains how to clean them. If clean filters make no difference, be prepared for the possibility that it is time for a new unit.

New noises or unusual smells

A working system should be quiet, with the occasional sound as it cycles. Any noise outside the norm means something is off. A small change might only need a repair, perhaps a fan fault or a part that has come loose. Persistent rattling, buzzing, screeching, grinding or ticking usually means a more serious problem and often warrants replacement.

The same goes for smells. A bad smell from the unit is not just a nuisance. It can point to problems with the insulation, or to mould. Dirt, mould or mildew inside the unit is a health concern, because the system circulates that air through your home. It can trigger allergies or worse, especially for small children and older people. Have it looked at straight away.

Leaks or excess moisture

A small amount of condensation dripping from the outdoor side of the system is normal. The rest of the unit should stay dry, whether or not it is running. Moisture inside the house, a sudden increase in condensation or a leak all mean it may be time to replace the system.

Have a technician inspect it straight away. The sooner the better, because water and electrical components do not mix. Once the source of the leak is found, you will know whether a repair or a replacement is the sensible spend.

Higher power bills and frequent repairs

A spike in your power use is more than a nuisance. Even if the system seems to be running normally, a jump in running costs can mean it is drawing extra power to hold the set temperature. A struggling system works harder and costs more.

Sometimes a vent clean or a filter change fixes it. Sometimes it is the end of the unit's working life. Have a technician find out why it has become less efficient.

Age catches up with every system too. Parts wear, newer technology is more efficient, and at some point replacing parts to keep an old unit going is no longer cost effective. Older units also tend to need more repairs, year after year. If you are calling someone out more than twice a year, it is probably time for a newer model.

Other reasons to upgrade before it fails

Some people hold onto an old system because it still works, an upgrade seems expensive, or they simply do not notice it. There are still good reasons to look at a replacement:

• Your house is bigger. If you have added living space, the old system may not be sized for it. See how big a system do I need.
• You are renovating. If the system is over ten years old and you are planning major work, include the air conditioning in the plan.
• You are selling. A tired system is something buyers will weigh up, so price an upgrade before you list.
• A new system is simply better. Newer systems cool more consistently, run more quietly and cost less to run. Past ten years of age, it is time to consider one.

Get quotes from several dealers, and pay attention to the warranty. Our guides on comparing quotes and warranties and the guarantee explain what to look for. To have your current system assessed, find an accredited dealer.

Signs it is time to replace

• Warm air on a cool setting, or cool air on a warm setting
• Weak airflow even with clean filters
• New rattling, buzzing, grinding or screeching noises
• A bad smell when the system runs
• Moisture inside the house, or a new leak
• A jump in the power bill with no change in use
• Repairs more than twice a year
• System over ten years old and a renovation or sale coming up

Deciding between a repair and a replacement needs an honest assessment. An ACDA accredited member runs a service department as well as sales, so they can tell you plainly which is the better spend.