How to Plan a Replacement, Including What Happens to the Old Unit

 Replacement quotes concentrate on the new system. The old one gets a line at the bottom, if it's mentioned at all, and that's where the surprises live.

Removing an air conditioner properly is regulated work with real steps attached. Knowing what those steps are tells you whether a quote is complete and whether the person doing it is the right person.

Decide whether you're replacing like for like

The cheapest replacement is a new unit of the same capacity in the same position using the same pipework. That's often the right answer and sometimes it isn't.

Ask whether the original system was correctly sized, since replacing an undersized unit with another undersized unit just resets the clock on the same complaint. Ask whether the position still suits the room, because layouts change. If the house has been extended, insulated or reglazed since the original install, the load has changed too.

Have the room reassessed rather than matching the sticker on the old machine.

Check how the room is used now as well. A spare bedroom that's become a home office has a different load and a different schedule from the one the original system was chosen for.

Find out whether the existing pipework can be reused

Reusing refrigerant pipework saves money and it isn't always appropriate.

Older pipe sized for a different refrigerant, pipe that's been in place a long time, or pipe with signs of corrosion may need replacing. Some manufacturers have requirements about flushing or replacing lines when changing refrigerant type, and ignoring that can affect the warranty on the new equipment.

Ask directly whether the quote includes new pipework or reuses the existing run, and what the installer's view is on whether it should be reused.

Know who can legally remove the old refrigerant

This is the part homeowners rarely think about, and it's not optional.

The refrigerant in the old system has to be recovered rather than released. The Australian Refrigeration Council issues different types of Refrigerant Handling Licence depending on the work being carried out, and recovery from existing equipment is licensed work.

If someone offers to pull the old unit off the wall cheaply, that's the question to ask. A scrap metal collector is not licensed to recover refrigerant.

Ask what actually happens to the old unit

Once the refrigerant is recovered, the hardware is metal and electronics.

Most reputable installers remove the old equipment as part of the job and dispose of it appropriately. Some charge for it, some include it, and a few leave it in your yard. Clarify which, because an outdoor unit sitting beside the house for three weeks is a surprisingly common outcome.

If you're disposing of it yourself, check what your council accepts and whether it goes to e-waste or scrap metal.

Don't leave it on the kerb on the assumption someone will take it. An outdoor unit that still holds refrigerant isn't general hard waste, and the gas has to come out before the metal goes anywhere.

Budget for the things that only appear once it's off the wall

A replacement often exposes what was behind the old unit.

Damaged render or brickwork around the core hole. A wall plate hiding a larger hole than the new unit covers. Perished sealant. A bracket that's rusted into the wall. Electrical work that was acceptable years ago and isn't now.

A good installer flags the likely ones at quote stage. Ask what happens if they find something, and whether making good is included.

Check the electrical side hasn't moved on

A new system may draw differently from the old one, and standards change over time.

The existing circuit may be adequate or it may need upgrading, and if the switchboard is older this is the moment that gets discovered. Ask whether an electrician is included in the quote and whether an electrical certificate will be issued.

Think about timing

Replacing a system in February means living without cooling during the worst of it, often at the busiest time for contractors.

Winter and early spring are easier on every count. Better availability, more time to order the right equipment, and no pressure to accept the first thing available.

Get the handover you didn't get last time

Most people inherit a system with no paperwork. A replacement is your chance to fix that.

Ask for the manual, the warranty documents, the electrical certificate, the licence details and a note of the model and serial numbers before the air conditioning experts in Brisbane doing the work leave the site. Put it all in one folder while you're thinking about it, because in three years you won't remember any of it.

 

Frequently asked questions

Can I reuse the existing pipework for a new system? 

Sometimes, depending on its age, size, condition and the refrigerant involved. Ask the installer to assess it rather than assuming either way.

Who removes the old air conditioner?

Usually the installer as part of the job, though whether it's included or charged varies. Refrigerant recovery is licensed work regardless of who does it.

What happens to the refrigerant in the old unit? 

It must be recovered by someone appropriately licensed rather than released. Ask how this is handled if the quote doesn't mention it.

Will the new unit cover the old wall marks? 

Not always. Different models have different footprints, and making good around the old position may be extra. Raise it before work starts.

When is the best time to replace?

Winter or early spring. Availability is better, there's time to get the right equipment, and you're not without cooling in the heat.