General Service vs Chemical Wash — What Is the Difference?
Two services, two very different jobs. One is maintenance. One is recovery. Knowing which you need stops you from paying for the wrong fix.
What a General Service Covers
A general service is routine maintenance. It clears the buildup that accumulates with normal use.
The technician cleans the air filter, wipes down the evaporator coil surface, flushes the condensate drain line, checks that the drain pan is clear, and runs a basic check on refrigerant pressure.
Homes that service on a regular schedule need this type of visit. It keeps the unit running at its designed efficiency and prevents the buildup that leads to leaks and weak cooling.
What a Chemical Wash Does
A chemical wash goes deeper. The technician uses a cleaning solution to dissolve grime from inside the coil — the kind of buildup that wiping cannot reach.
The indoor unit is partially or fully disassembled. The coil is soaked or sprayed with the cleaning agent, which breaks down oil residue, mould, and compacted dust. The drain system is also flushed thoroughly.
This is a recovery service. It restores a unit that has been neglected or has not responded to general servicing.
When Each One Is the Right Call
General service is right for units on a regular schedule. If the unit cools well and has been serviced recently, general service is all you need.
Chemical wash is right when the unit has gone a long time without a clean, when a recent general service did not restore cooling, or when there is a persistent mould smell that does not clear after servicing.
It is not an upgrade to general service. It is a step you take when general service is not enough.
| Situation | Right Service |
|---|---|
| Routine maintenance, unit on schedule | General service |
| Unit not serviced for a long time | Chemical wash |
| General service done, cooling still weak | Chemical wash |
| Persistent mould smell after servicing | Chemical wash |
| New unit, first service | General service |
| Pre-tenancy or post-renovation | Chemical wash |
When Chemical Wash Is Being Oversold
Chemical wash costs more than a general service. That creates an incentive to recommend it when it is not needed.
If a technician recommends a chemical wash on a recently serviced unit that is cooling normally, ask what specifically they found that general service cannot fix. If there is no clear answer, general service is the right call.
Chemical wash on a well-maintained unit does not extend its life. It just costs more.
What Happens After a Chemical Wash
The unit should cool better within the first run after the wash. Airflow should feel stronger and the room should reach temperature faster.
If it does not improve, the problem is not buildup — it is something else. Weak cooling that persists after a chemical wash points to refrigerant issues, a failing compressor, or an oversized room for the unit's capacity.
A chemical wash that does not improve performance is a signal to assess the unit properly, not to book another wash.