Los Angeles heat waves have become longer, hotter, and more frequent in recent decades. Extended stretches of 100°F+ temperatures in the San Fernando Valley stress not just your body, but your home’s systems — plumbing, HVAC, and electrical infrastructure all see elevated failure rates during heat events. Preparing in advance makes the difference between manageable discomfort and a $5,000 emergency repair.
HVAC Preparation
Your air conditioning system works hardest in summer, and the most common HVAC failures happen during the first major heat wave of the season. Steps to take in May or early June:
- Replace the air filter (a clogged filter makes the system work significantly harder)
- Clear 2 feet of clearance around the outdoor condenser unit — vegetation and debris restrict airflow
- Clean the condenser coils with a garden hose (power off first)
- Schedule a professional AC tune-up — technicians book up quickly once hot weather arrives
- Set your thermostat to 78°F during the day when home, and no lower than 85°F when away — LADWP recommends these settings to reduce grid stress and your bill
Plumbing Stress During Heat Waves
Heat waves create specific plumbing challenges that many homeowners don’t anticipate:
- Water heater overworking: When ambient temperatures spike, water entering the home is hotter than usual, but thermostats in older water heaters may not compensate properly. Check that your heater’s thermostat is set at 120°F to avoid scalding.
- Pipe expansion: Metal pipes expand in heat. In homes with older galvanized supply lines, thermal expansion can stress already-compromised joints. Listen for new ticking or knocking sounds from pipes — this warrants a plumber’s inspection.
- Increased water demand: During heat waves, household water use rises 20–30%. Running additional laundry and showers can expose existing pressure or flow issues that weren’t noticeable under normal demand.
- Outdoor supply lines: Exposed garden hose bibs and irrigation supply lines in direct sun can become extremely hot. Protect exposed irrigation components from direct afternoon sun where possible.
Protecting Your Water Heater
The water heater is the single home appliance most likely to fail during a heat wave. High ambient temperatures in garages (which can exceed 140°F during summer in the Valley) significantly reduce water heater efficiency and accelerate tank corrosion. Consider:
- Adding pipe insulation to the first 6 feet of both hot and cold water connections
- If your heater is 10+ years old and located in a hot garage, budget for replacement before peak summer
- A tankless water heater eliminates the “hot garage” problem since there’s no standing water to overheat
Electrical Load Management
Heat waves push the electrical grid near capacity. To reduce risk of an outage:
- Run major appliances (washer, dryer, dishwasher) before 4pm or after 9pm
- Use a programmable thermostat to pre-cool the house before peak rates kick in
- Unplug electronics that generate heat when not in use
Emergency Cooling Resources
LA County operates cooling centers during extreme heat events — typically libraries, community centers, and government buildings. LADWP and the County provide information on locations through their websites and social media during declared heat emergencies.
For guidance on choosing a plumber if a heat-related plumbing failure occurs, our Home Plumbing Guide for LA Residents covers what to look for in a licensed contractor.