Quick answer
- Before the storm: shut off power to the outdoor condenser at the disconnect — not just the thermostat.
- Cover the outdoor unit only AFTER you shut off power, and only with breathable material.
- Secure or move loose outdoor objects that could become projectiles (lawn chairs, grills) — they damage condenser coils.
- If your home floods: do NOT power the system back on. Salt-water contact on electrical components requires professional inspection.
- Post-storm: visual check for debris in the condenser, then a professional check before restarting if any flooding occurred.
Why hurricane prep for HVAC matters
HVAC equipment is one of the most expensive single losses in a hurricane. A flooded condenser is rarely repairable — salt water and corrosion destroy compressor windings and electrical contactors within hours. A storm-damaged unit replaced reactively, during the post-storm contractor rush, costs more and takes longer than a planned replacement.
The good news: most HVAC hurricane damage is preventable with a 30-minute checklist done before the storm makes landfall.
Before the storm
1. Shut off power at the disconnect
Find the gray weatherproof disconnect box on the wall next to your outdoor condenser. Pull the disconnect (or flip the breaker if it's a switched type). This cuts power to the outdoor unit independent of your thermostat — preventing the system from trying to start if there's any moisture or debris contact.
2. Cover the outdoor unit (optional)
If you choose to cover it (helps prevent debris damage), use a breathable cover like a tarp, plywood lid, or specifically a hurricane HVAC cover. Do NOT use plastic sheeting — it traps moisture inside. Cover AFTER you've cut power, never before.
3. Clear projectiles
Move lawn chairs, grills, garden tools, planters, and anything else within 20 feet of the condenser to a garage or shed. In 100+ mph winds, these become projectiles that can puncture the condenser coil — turning a recoverable system into a total loss.
4. Document the unit
Take photos of the outdoor unit and the data plate before the storm. If you have an insurance claim later, photos of the pre-storm condition are useful.
During the storm
Leave power off at the disconnect. The thermostat should NOT be set to AUTO with cooling enabled, because if grid power flickers, the system may try to start with debris contact or water intrusion that hasn't drained.
After the storm
If your home did NOT flood
- Remove any cover from the outdoor unit.
- Walk around the unit and check for debris in the fan grille, bent fins, or visible damage.
- Clear any leaves, branches, or debris from around the unit.
- Restore power at the disconnect.
- Set the thermostat to cooling mode at a normal setpoint and listen for the outdoor unit starting.
- If you hear unusual sounds (grinding, screeching, repeated humming), shut it back off and call us.
If your home flooded — STOP
Flooded systems often look fine externally but have water in the contactors, compressor windings, or refrigerant lines. We can inspect, drain, and replace damaged components — but only if you haven't restarted the unit first.
What to do next
Add HVAC hurricane prep to your storm checklist now, before you need it. We're happy to walk you through your specific equipment by phone before any named storm — most prep takes 30 minutes once you know where the disconnect is.
Have a question about your system?
Talk to a real Charleston Lowcountry technician — a family-owned team with 30+ years of local experience that installs and services Carrier, Trane, Rheem, and more.