Replacing at a high floor: why we staged it by system
The quote covered both systems in the flat, replaced together in one visit. Only one had actually failed. At a high floor the access cost pushes toward doing everything at once, which is exactly when the sequencing needs checking.
By Team Snowflake | Reviewed 25 Jul 2026
Case summary
Mitsubishi Electric Multi-split15 years oldCondoNewton, Singapore
- Concern
- A single price had been put forward for both systems, indoor and outdoor units together. The reasoning was that ledge access at this height is the expensive part.
- Found
- One system had reached the end of its working life while the second still performed within its original range
- Key check
- Measuring cooling output and running power on each system separately instead of judging both by their shared age
- Result
- Half the equipment in the flat stayed where it was. The living area went back to full cooling on the new system, and the bedroom system is still in service on its own schedule.
What we were told
The living and dining area had gone warm and stayed warm, while the bedrooms still cooled fine. Both sets of equipment went in with the original fit-out and had never been replaced. A contractor had been up to look and came back with one price covering everything in the flat.
What we checked
Each system was tested on its own terms. Two units of the same age can sit in very different condition, and the ledge at this height does not treat them equally. We ran both through a full cooling check, then measured what each drew to hold the same room temperature. The living area system was the one under question. The bedroom system needed a verdict of its own.
The living area outdoor unit held almost no pressure and the coil face was corroded through in places.
Its compressor drew heavy power for weak output, so the running cost had climbed with no cooling to show for it.
The bedroom outdoor unit cooled to within range and drew close to its original figures.
What we found
The living area system was worn out. The coil had lost surface to corrosion and the compressor no longer moved enough gas to cool the space. Nothing about that argued for the bedroom system. It sat on a shaded part of the ledge, ran fewer hours, and still tested close to where it started. Age was the only thing the two shared.
What fixed it
We recommended replacing the living area system now and leaving the bedroom system in service. Doing both at once would have scrapped working equipment to save one round of ledge access, and that access is a modest line next to the price of a second system. We set a review point instead. When the bedroom system starts losing output or drawing more power, it gets replaced then, on its own timing.
Outcome
Half the equipment in the flat stayed where it was. The living area went back to full cooling on the new system, and the bedroom system is still in service on its own schedule.
What this case teaches us
Shared age is not shared condition
- Two systems bought at the same time rarely wear at the same rate. Room use, sun exposure, and ledge position all pull them apart.
- Ask for cooling output and running power on each system separately. A single quote for the whole flat hides which unit is actually finished.
- Access cost at a high floor is real, but it is a small share of a full replacement. It rarely justifies scrapping a system that still works.
Questions this case answers
Do I need to replace every aircon unit at the same time?
Is it cheaper to replace both aircon systems in one visit?
Which unit should be replaced first if both are the same age?
What happens to the older unit I decided to keep?
Ready to get started?
Tell us what’s going on. Symptoms, setup, photos, anything we should know. We’ll assess and come back with the right next step.