Told a Near-New Unit Needed a Wash: Dust on the Filter
A two-year-old system is quoted for chemical washing throughout. What settles whether any of that work is needed yet.
By Team Snowflake | Updated 24 Aug 2026
Teaching case based on recurring Snowflake service patterns; identifying details are combined.
How this presents
Cooling strong since installation with nothing gone wrong, on units around two years old. At the first booked service the filters were rinsed and a quote followed covering chemical washing on all three rooms. No symptom was described and no fin condition was shown.
- Setup
- LG Wall-mounted7-9 yearsHDBPunggol
- Misread as
- Every unit due for chemical washing, on a system barely two years into service.
- Check first
- The fin face under torchlight, for colour change and blocked gaps
What else produces this
Age sets an expectation that can be checked directly rather than argued about. A young unit in a bedroom with closed windows should hold dust on its filters and very little past them, because that is what filters are for. So the question is not whether a wash is ever justified but whether these fins show the deposit that justifies one, and a torch answers that in seconds.
Filters holding a normal grey dust mat that rinses clean under a tap, with no staining left behind, is filters working.
Fin faces still bright metal with clear gaps, and a torch shining straight through the block, show nothing to dissolve.
Supply air properly cold with airflow reaching the far wall means nothing is restricting the coil.
No symptom described and no fin condition shown means the recommendation rested on age alone.
Why it happens
A chemical wash exists to remove what mechanical cleaning cannot reach: deposits bound into the fin depth, hardened or biological. A young unit in dry indoor air has not had the time or the exposure to build any. Setting a wash by years in service rather than by fin condition puts the price ahead of the inspection, and on these fins there was nothing for a solution to do.
What resolution involves
A routine service covers it: filters washed and dried, fin face brushed and vacuumed, drain pan wiped, pipe flushed, condenser rinsed. No solution used, and the scope stays inside a normal visit. What is worth recording is the point at which a wash does become correct here, so the next decision has something to test against rather than another year on the clock.
How to tell it worked
Ask to see the fin face before agreeing to a wash. A torch through the block settles it in seconds, and a bright coil with clear gaps has nothing a chemical can remove that a brush cannot.
Before you approve a quote
A wash is a condition, not a service interval
- Ask what on the fins justifies it. A wash removes bound deposit, and bound deposit is visible.
- Filters holding dust is filters working, not a symptom. What matters is what got past them.
- Strong cooling and clear airflow are evidence, and they are evidence against. Say so.
Related diagnostics
Questions this case answers
Is a chemical wash worth it on an aircon that is only a year or two old?
Servicing crew says every unit needs chemical washing, is that normal?
When does a chemical wash actually become necessary?
Can strong cooling be a reason to say no to a wash?
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.