Replacing a Split System: What to Check First
Before you replace a split system, four things need to be checked: the existing power supply, the diameter of the existing line set (the refrigerant pipes), the refrigerant type the old system used and the cabling between the indoor and outdoor units. Getting these right decides whether the old pipes and cabling can be reused safely, or need to be replaced, before a new system goes in.
- Existing power supply
- Existing line set diameter
- Existing refrigerant type
- Existing communication cabling
1. Existing power supply
Before replacing a split system, the existing power supply must be checked to make sure there is no risk of fire or electrocution. Specifically:
- The correct size cabling to the air conditioner must be confirmed.
- The correct size circuit breaker serving the air conditioner must be confirmed.
- The correct size cabling between the indoor and outdoor units must be confirmed.
- Whether the power supply goes to the indoor unit or the outdoor unit must be confirmed.
2. Line set diameter
Two insulated copper pipes connect the indoor unit to the outdoor unit. Line sets are not uniform. Their size is specific to the brand, capacity and refrigerant of each split system.
If you are replacing a split system and reusing the line set, the new split system needs the same line set diameter. If the pipes are larger than required, there will be an abrupt pressure loss. If they are smaller than required, high pressure refrigerant can flood the evaporator.
Both problems reduce performance, can void the manufacturer's warranty and can create a safety risk.
3. Existing refrigerant type
Three refrigerants are commonly found in split systems in Australia: R-32, R-410A and R-22. Each has a different chemical make up, performance and thermodynamic behaviour. R-22 was the first generation, R-410A the second and R-32 is the third.
If you plan to reuse the line set, it is important to either choose an air conditioner that uses the same refrigerant, or carry out a complete line set flush to remove any particles, oil or acid that has built up inside the pipes before a new refrigerant is introduced.
If a different refrigerant is introduced without the correct recovery, purging, flushing and filtering, contaminants and incompatible oil left in the pipes can break down the oil that lubricates the compressor, and the compressor can quickly fail.
Replacing an R-22 system? New R-22 air conditioning equipment has not been allowed to be imported or manufactured in Australia since 2010, and imports of R-22 refrigerant will be banned entirely from 1 January 2030, after which servicing will rely on reclaimed refrigerant. Read more in our guide to split system refrigerants.
4. Communication cabling
In many modern split systems the power supply goes to the outdoor unit, which then powers the indoor unit. In many older split systems it was the opposite, with power going to the indoor unit, which powered the outdoor unit.
When replacing a split system, it is important to make sure the power supply is not incorrectly used as communication cabling, the wiring sequence is correct and the cable is the right size, so there is no risk of thermal overload or fire.
Reusing your existing line set
In 2007, EZYAIR introduced a specific technique that allows us to reuse a suitable existing line set without cutting it out and replacing it with new, backed by our 5 year installation warranty.
What happens to your old system
The refrigerant in your old system needs to be recovered by a licensed technician before the unit is removed. See our decommissioning and removal service, or read more about replacing an air conditioner with EZYAIR.
If you are replacing an old heater as well as cooling, you may also be eligible for a Victorian Energy Upgrades (VEU) discount. EZYAIR is an accredited provider under the VEU program (accreditation A2261).
Frequently asked questions
Can I reuse the pipes from my old split system?
Often, yes, if the line set is the right diameter for the new system and either uses the same refrigerant or is properly flushed before a new refrigerant is introduced. The pipes and cabling need to be checked first.
Can I replace an R-22 split system with an R-32 one?
Yes, but the existing line set must be assessed and, if it is reused, properly recovered, purged, flushed and filtered so old oil and contaminants do not damage the new compressor.
Why does the power supply need checking when I replace a split system?
The cabling, circuit breaker and connection point must suit the new system to avoid any risk of fire, electrocution or thermal overload.
What happens to my old air conditioner?
The refrigerant must be recovered by a licensed technician before the old unit is removed. EZYAIR offers decommissioning and removal as part of a replacement.
Related guides
Keep reading with these related EZYAIR guides:
- Split System Refrigerants: R-32, R-410A and R-22 Explained
- What Is a Split System Air Conditioner?
- BTU, Kilowatts or Horsepower? Air Conditioner Sizes Explained
- Correct Termination of Air Conditioner Condensate Drains
- VEU Accredited Provider and Air Conditioning Licences in Victoria
Talk to EZYAIR
Ezy Air Conditioning & Heating Pty Ltd (EZYAIR) has been helping Melbourne homes and businesses with heating and cooling since 2007. If you have a question about replacing your split system or would like a quote, contact our team or call 1300 399 247, Monday to Friday, 9am to 5pm.
Our head office and display centre is at 49 Huntingdale Rd, Burwood VIC 3125.
