Extreme heat: what a desert summer does to a house, a car and a policy

From June until the monsoon breaks the pattern, the low desert lives under a heat dome. Phoenix, Tucson, Yuma, Las Vegas and the Mojave towns along the Colorado see weeks of afternoons where roofs and asphalt run far hotter than the air, nights that never cool, and a power grid running at its limit. St. George and Boise run cooler but see their own runs of triple-digit days, and a mountain house in Utah or Idaho that was never designed for cooling can be the most uncomfortable of all.

Heat does not make headlines the way a storm does, and it does not appear on a policy as a named peril. It works slowly, on materials and machines, and the losses it produces are mostly ones a policy classes as wear, maintenance or mechanical failure. Knowing which heat losses are covered, which are not and which can be endorsed is the whole of the insurance question. This guide covers that and the practical steps that keep the uninsured losses small.

What sustained heat does

The damage is cumulative rather than sudden, which is exactly why policies struggle with it.

• Roofs: asphalt shingles lose their oils and curl, foam and flat roofs blister, and tile underlayment cooks and cracks long before the tiles show it. A roof in the low desert ages faster than the same roof in a cooler climate, and carriers know it.
• Air conditioning: compressors run continuously for months and fail at the hottest point of the season, when every repair company is booked. A failed system in a closed house also produces heat damage to finishes and contents.
• Plumbing and water heaters: hot supply lines, attic pipes and pool equipment run near their limits. Water heaters and irrigation valves fail; a burst attic line floods the house from above.
• Electrical: outages during a peak-demand evening and surges when power returns damage appliances, pool pumps and electronics.
• Cars: batteries die, tyres over-inflate and blow, dashboards and interiors crack, and anything left in a closed car reaches oven temperatures. Engines and transmissions run hot on a freeway grade in August.
• Boats and RVs: gelcoat fades, seals shrink and refrigerators fail in storage; a boat cover that traps heat does more harm than none.
• Businesses: walk-in coolers and refrigeration lose the fight, stock spoils, outdoor work slows or stops, and a shop without cooling loses its customers to the one that has it.

What the home policy pays for, and what it does not

A standard homeowner form pays for sudden and accidental direct physical loss from a covered peril, and heat by itself is not one. Gradual deterioration, wear and tear, and mechanical breakdown are excluded on every standard form. That puts a roof that has simply aged out, a compressor that has died of overwork and a water heater that has rusted through in the not-covered column, however hot the summer was.

What the policy does pay for is the ensuing damage when the cause is sudden. A supply line that bursts in the attic is a covered water loss to the ceiling, the floors and the contents even though the pipe itself, as a worn part, may not be. Lightning that takes out the air handler is covered. A fire that starts in a failed appliance is covered. Food that spoils in a power outage is covered only when the form or an endorsement says so, and then to a small limit; check whether the outage must have started on your property or whether an off-premises outage also counts, because carriers split on this.

Two endorsements change the picture. Equipment breakdown coverage, offered by many carriers for a small addition to the premium, pays to repair or replace home systems that fail from a mechanical or electrical cause, including air conditioners, and is one of the few ways to insure the compressor itself. Service line coverage pays for the buried water, sewer and power lines between the street and the house, which fail in heat-cracked soil. Neither is on a base policy unless added.

Cars, boats, RVs and the business

On an auto policy, the comprehensive coverage pays for damage from fire, theft, vandalism, falling objects and weather events, but not for a battery, a tyre or an engine that failed from heat; those are maintenance. A blown tyre that causes a crash is a collision claim, paid under collision coverage less the deductible. Heat-cracked glass is often paid under comprehensive, and some policies carry a separate glass deductible. Interior damage from sun is wear. The same logic applies to a boat or RV policy: sudden events are covered, deterioration in storage is not, though some RV forms include an appliance and equipment breakdown option worth asking about.

For a business, a commercial property policy or a business owner's policy excludes mechanical breakdown of the refrigeration unit but can be endorsed for equipment breakdown and for spoilage, which together pay for the failed cooler and the stock lost inside it. Utility service interruption coverage adds losses from an off-premises outage. Business income coverage responds only to a covered physical loss, so an outage with no damage on the premises pays nothing without that endorsement. Workers compensation does respond to heat illness in an employee, and an employer with outdoor crews should plan schedules and water around that.

Before the season

Late spring, while contractors are still available.

• Have the air conditioner serviced and keep the invoice. A carrier reviewing an ensuing-loss claim wants to see maintenance; the invoice also proves the unit was working before the event.
• Walk the roof or have it walked, and photograph it. Ask the carrier whether the roof is covered at replacement cost or on a depreciated schedule; in the desert, the difference decides whether a hail or wind claim next year pays for a new roof or a fraction of one.
• Insulate attic pipes and check the water heater's age; replace it before it fails rather than after.
• Install whole-house surge protection at the panel and point-of-use protection for expensive electronics; ask whether the policy pays for surge damage from an off-premises cause.
• Ask for equipment breakdown and, if the house has old buried lines, service line coverage. Both are small line items relative to what they replace.
• For cars: test the battery, check tyre pressure cold, and never leave children, pets, medication or aerosols in a closed vehicle.
• For a business: service the refrigeration, add spoilage and equipment breakdown if the stock warrants it, and write the heat-illness plan for staff who work outdoors.

During a heat emergency and after a loss

When the air conditioner fails, the first hours matter for the house as well as the people in it. Close blinds, run fans, move anyone vulnerable to a cooler place, and get a repair booked. If the failure has caused water damage or a fire, stop the source and report the claim the same day. If a power outage has spoiled food, photograph the contents of the refrigerator and freezer before you throw them out and keep the utility's outage notice; that is the whole evidence file for a spoilage claim.

For a burst pipe, shut the main, photograph the water line on the walls and start drying within hours; the policy pays for the damage the water did, and mould that grows because drying was slow becomes an argument. Keep receipts for fans, dehumidifiers, a hotel night and any emergency repair. Report promptly and describe the event as it happened: a line that failed suddenly is a covered water loss; a line that had been dripping for weeks is a maintenance loss, and the adjuster will ask which it was.

A worked example

Suppose a Mesa household carries a homeowner policy with a $1,500 deductible and, at renewal, adds an equipment breakdown endorsement for $40 a year. In late July the fifteen-year-old air conditioner's compressor fails during a heat advisory. A replacement system costs $9,000. Without the endorsement the policy pays nothing, because a worn compressor is mechanical breakdown; with it, the carrier pays $9,000 less the $1,500 deductible, or $7,500. The figures are illustrative, but the mechanism is the reason the endorsement exists.

Say the same household, two weeks later, has an attic supply line burst overnight. Water soaks the ceiling, two bedrooms and a hallway of wood flooring. The repair estimate is $22,000. That is a covered sudden water loss; the policy pays $22,000 less the $1,500 deductible. The pipe itself, at a few dollars, is excluded as a worn part and nobody cares. A month of drying receipts and two hotel nights are added under loss of use. Again the numbers are hypothetical; the point is that the ensuing damage is what the policy insures, not the part that failed.

The decision points

Three decisions, all made before June. Whether to add equipment breakdown coverage, which turns the summer's most likely failure into a covered one. Whether the roof is at replacement cost or on a schedule, and whether to replace it before a carrier's inspection retires it for you. And whether the house has surge protection and a serviced system, which is what keeps the uninsurable losses small. If the policy already carries the endorsement and the roof is at replacement cost, the recommendation is to service the air conditioner and do nothing else. We read the declarations page and tell you which case you are in; the analysis costs nothing.