Most Central Coast cafe AC problems trace back to one of the same six causes. The good news is that four of them are fixable in an hour and don't need parts. Here they are in rough order of how often they come up on a Long Jetty service round.
1. Undersized for kitchen heat
The most common issue, and the hardest one to fix cheaply. The previous owner installed a system sized for an empty office and now you're running a kitchen that puts out 5 kW of heat through the cooktop alone. The system runs constantly, never quite reaches set point, and the room stays at 26°C through summer. The right answer is usually adding a second unit or upgrading capacity — but it's worth checking the cheaper causes first.
2. Blocked filters
In a cafe environment — cooking oils, flour, dust — AC filters need cleaning monthly, not yearly. A blocked filter forces the unit to work harder for less cooling, and over time it pulls grime through the indoor coil too, which is much harder to clean. Pull the filter out, vacuum or rinse, dry, replace. Five minutes a month.
3. Refrigerant leaks
A hissing noise near the indoor unit, or a system that's steadily losing cooling capacity, points to a refrigerant leak. Refrigerant doesn't get used up in normal operation — if the levels are dropping, gas is escaping somewhere. Leak detection and repair is a technician job, not a DIY one, but catching it early stops the compressor from running dry and burning out.
4. Thermostat in the wrong spot
A thermostat installed near the kitchen reads 28°C and tells the AC to keep going long after the dining room has reached 21°C. A thermostat in direct afternoon sun reads warmer than the rest of the room. A thermostat next to the front door gets blasted with hot air every time it opens. Each of these makes the AC behave erratically and run far longer than necessary. Relocating the thermostat is usually a one-hour job and fixes a surprising number of comfort complaints.
5. Drainage problems
AC units produce condensate — water pulled out of the air — and that water has to drain away. A blocked condensate drain (algae, dust, or a kinked hose) means water backs up, drips through the ceiling or shorts out a sensor. The fix is a drain flush, usually included in any proper service.
6. Central Coast humidity
It's not a fault as such, but it's an aggravating factor that surprises people. Central Coast summer humidity (which the Bureau of Meteorology data shows regularly sitting above 80% on hot days) makes every AC system work harder than the same unit would inland. A system that just copes in February in Sydney's western suburbs can struggle on the Coast. Sizing assessments need to allow for this, which is one of the reasons online calculators consistently undersize Central Coast cafes.
Pre-summer servicing catches most of these before the heat hits. Read about my commercial refrigeration servicing or local coverage on the Long Jetty area page.