- Check 1
- Filter
- Check 2
- Indoor coil
- Check 3
- Outdoor condenser
- Check 4
- Gas leak, then electricals
The diagnostic order
| Order | Check | Fix | Aerosure product |
|---|---|---|---|
| 1 | Filter blocked with dust | Wash or replace the filter | None |
| 2 | Indoor coil dirty or greasy | Foam clean the coil | Aerosure AC Foam Cleaner |
| 3 | Outdoor condenser blocked by dust and fluff | Clean the condenser coil | Aerosure AC Coil Shining Concentrate |
| 4 | Low gas | Find the leak first, repair, then recharge | Aerosure AC Leak Detector |
| 5 | Electrical fault | Check capacitor, fan motor and PCB | Aerosure Contact & Electronic Cleaner for dirty contacts |
What dirty coils do to performance
The US Department of Energy explains that dirt on coils reduces airflow and insulates the coil, cutting its ability to absorb heat [1]. Berkeley Lab found typical efficiency and capacity losses from coil fouling of under 5%, but much larger losses for marginal systems or extreme conditions [2]. In Indian summers, with dust and long running hours, a fouled coil is often the difference between a cold room and a complaint.
Prove the fix to the customer
Measure the air temperature at the grille before and after the service, photograph the coil before and after, and note it on a service checklist.
Products used
Quick answers
Why is my split AC not cooling after service?
Common reasons are a coil that was only rinsed on the surface, a dirty outdoor condenser, a gas leak that was recharged without repair, or a filter refitted wet and blocked. Check the condenser and look for leaks before recharging again.
Does a dirty coil reduce AC cooling?
Yes. Dirt reduces airflow and insulates the coil, so it absorbs less heat. The effect is larger on older or marginal units.
What should I check first when an AC is not cooling?
Check the filter, the indoor coil and the outdoor coil for dirt, then the thermostat setting and the outdoor fan. Dirt is the most common cause before any gas or electrical fault.
Does a low star rating AC cool less?
Star rating measures efficiency, not capacity. Check the BEE star label and ISEER when comparing running costs.