The systems in your house most likely to fail during extreme weather

As extreme heat, deep freezes and violent storms become more common, the weakest links in a house are showing up faster and failing harder. The systems that quietly keep daily life running, from HVAC to wiring to plumbing, are now on the front lines of climate stress. Knowing which ones are most likely to break under pressure is the first step to keeping a home safe, habitable and financially manageable when the weather turns hostile.

I see the same pattern in the data and in homeowner stories: a handful of critical systems fail again and again, often in predictable ways that can be prevented with basic maintenance and a few strategic upgrades. The goal is not to bulletproof every square foot, but to focus on the components most likely to go down when you can least afford it.

Climate risk is now baked into everyday home systems

For a long time, climate risk sounded like something reserved for coastal mansions and wildfire canyons. That is no longer true. A report examined by Grist and based on data from Realtor found that slightly more than 1 in 4 U.S. homes faces severe risk from extreme weather, which means the odds are no longer abstract. That risk shows up not just in insurance premiums but in how often furnaces, air conditioners, sump pumps and electrical panels are pushed to their limits.

Homeowners are starting to respond. One survey of 2,000 U.S. homeowners commissioned by Hippo Insurance used a detailed survey to show that winter problems like drafts, ice dams and frozen pipes are already costing people real money. At the same time, building-product researchers report that 54% of consumers now say resilience is a top priority in construction materials, with 63% of women and 47% of men placing a premium on durability. That shift in expectations is reshaping which systems get upgraded first and how much tolerance people have for preventable failures.

HVAC: the system most likely to fail when you need it most

Heating and cooling equipment sits at the top of the failure list because it is forced to work hardest during the very conditions that threaten it. When temperatures spike, Common Summer HVAC Failures and How to Avoid a Total Shutdown often start with Compressor Failure, and the section labeled Why It Happens points to long runtimes, dirty coils and low refrigerant as common triggers. In winter, How Weather Impacts Your HVAC System explains that Snow, Frost, and Ice can clog outdoor units and damage fan blades and coils. In both seasons, the system is being asked to run at full tilt just as its weakest parts are being stressed by the elements.

Most of those breakdowns are not freak accidents. A list of Common Causes of HVAC Breakdowns and How To Prevent Them starts with Clogged Air Filters, and stresses that Proper airflow through the HVAC system is essential to keep motors from overheating. Another guide on Prepping Your HVAC System for Severe Weather warns that loose Electrical Connections can cause shorted circuits and damage sensitive components during storms. When I look at those patterns together, the message is blunt: the system most likely to fail during a heat wave or blizzard is the one that has been limping along with dirty filters, neglected wiring and no seasonal tune-up.

When HVAC stops in extreme weather, safety comes first

Once a furnace or air conditioner actually quits during a cold snap or heat wave, the priority shifts from comfort to survival. The guide titled What to do if Your HVAC Stops Working in Extreme Weather opens its Key Takeaways with a simple rule: Safety Comes First. In cold weather, that means sealing windows, closing off unused rooms and dressing in layers to stay warm while you wait for repairs. In extreme heat, it means moving to the coolest part of the home, using fans, staying hydrated and, if indoor temperatures keep rising, getting to a public cooling center or a friend’s air conditioned space.

Understanding why the system failed can also help you avoid a repeat. The same Key Takeaways note that systems often fail due to dirty filters, blocked vents or frozen coils, problems that can be spotted and fixed before the next storm. A separate list of 20 Common Heating Issues points out that Here are a few causes of impeded airflow, including Closed vent registers and leaks in ductwork that force the blower to work harder or even burn out, sometimes requiring a technician to repair or install a new motor. In other words, the emergency you are dealing with today is often the bill for maintenance that did not happen last season.

Plumbing, sprinklers and hidden water risks in deep cold

Water systems are another quiet workhorse that can fail spectacularly in extreme cold. Municipal fire officials warn that Frozen fire sprinkler systems in residential homes can be just as damaging as a fire or a burst water pipe, because ice expansion can crack fittings and trigger uncontrolled leaks once temperatures rise. Standard plumbing is just as vulnerable. A winter maintenance advisory that urges people to Schedule Chimney Cleaning to Reduce fire and carbon monoxide risks also stresses the importance of keeping water in the pipes moving, especially in unheated areas like garages and crawl spaces.

Cold is only half the story. When heat waves arrive, moisture problems shift from freezing to expansion, condensation and mold. Inspectors who track 5 ways high heat can damage your house note that Here are some of the most common issues, and list Prevention steps like de‑humidification and shading to protect materials. They also warn that if your home is located in an area with expansive clay soils and you see new cracks or doors sticking, you should call a professional as soon as possible for help, because those signs can indicate foundation movement tied to moisture swings. In both hot and cold extremes, the plumbing and sprinkler systems that usually sit out of sight can become the source of the most expensive repairs.

Foundations, drainage and the slow-motion damage of heat and cold

Foundations rarely fail overnight, but extreme weather accelerates the damage. A detailed explainer on how How Improper drainage can damage a home’s foundation explains that water pooling around the base of a house can lead to excess moisture in the soil, which then expands, contracts and undermines structural stability. The same piece lists “Red Flags” like new cracks, sloping floors and doors that no longer close properly, and urges homeowners to keep an eye out for problems before they become structural emergencies. In heat waves, soil can shrink away from the foundation, while in prolonged wet periods it can swell, and both cycles put stress on concrete and masonry.

Those stresses are not limited to the foundation itself. An energy-efficiency analysis of how Feb storms and heat waves affect homes notes that beyond power loss, water damage and insulation breakdown can lead to skyrocketing bills and frequent breakdowns of mechanical systems. Over time, that combination of foundation movement, moisture intrusion and degraded insulation can warp framing, crack drywall and strain doors and windows, turning what looks like a cosmetic issue into a whole‑house performance problem.

Electrical systems and the fragile grid behind your walls

Even the best maintained home systems are only as reliable as the power feeding them. Grid analysts warn that Weather-related equipment failures, combined with thermal generator outages or derates due to lack of fuel or contaminated fuel, are raising the risk of blackouts during severe cold snaps. Inside the house, electricians who specialize in storm preparation say Common Electrical Risks During Extreme Weather include voltage surges that can fry appliances, outages that disable critical medical equipment and heavy rain or floods that leave outlets and panels contaminated until a professional clears them.

Those risks are magnified by the way storms interact with home wiring. The same guide on Extreme conditions notes that surges can damage your electronics and appliances, leading to expensive repairs or replacements, while strong winds can knock down power lines that should only be handled by professionals. On the efficiency side, analysts tracking how Feb storms are challenging home energy performance warn that more frequent outages and equipment failures are already driving up repair costs. For homeowners, that means surge protection, panel inspections and backup power plans are no longer optional extras but core parts of keeping the lights on and the HVAC running.

Seasonal stressors: how each season attacks a different system

One of the most useful ways to think about home risk is by season, because each part of the year tends to attack a different system first. A practical guide that notes Different seasons bring unique stressors explains that in cold weather, pipes may freeze and heating systems are pushed to their limits, while in warm months, humidity and heat strain air conditioning and can warp building materials. That same seasonal lens shows up in the winter risk survey of 2,000 homeowners by Hippo Insurance, which found that drafts from poor insulation and ice buildup are among the most common cold‑season headaches.

Architects and planners are now building that seasonal thinking into long‑term resilience plans. A Checklist to Address Climate Changes from Nathan Kipnis of Kipnis Architecture + Planning includes steps like pruning vegetation in wildfire‑prone areas and checking for off odors that can signal gas leaks after storms. On the materials side, researchers who found that Additionally, 63% of women and 47% of men now value resilience are seeing more demand for impact‑resistant roofing, moisture‑tolerant insulation and siding that can handle both intense sun and driving rain. The throughline is clear: every season brings a different attack, and the homes that fare best are the ones whose owners plan for those cycles instead of reacting after the fact.

How to prioritize upgrades before the next storm hits

With so many potential failure points, the hardest part for most homeowners is deciding where to start. I find it useful to begin with the systems that are both critical to safety and most likely to be stressed by extreme weather: HVAC, electrical, plumbing and drainage. Energy analysts who track how Feb storms are challenging home efficiency point out that beyond power loss, water damage and insulation breakdown can lead to frequent breakdowns of mechanical systems, which means a dollar spent sealing air leaks or improving drainage can prevent multiple future repair bills. A seasonal guide that notes Different stressors by season suggests simple triage: in winter, focus on pipes and heating; in summer, prioritize cooling and moisture control.

On the mechanical side, the advice is remarkably consistent. The list of Common Causes of HVAC Breakdowns and How To Prevent Them makes a strong case for routine filter changes, duct inspections and professional tune‑ups before peak seasons. The severe‑weather prep guide that highlights Severe storms and their impact on Electrical Connections recommends checking wiring and securing outdoor units so flying debris and power surges do not turn a minor storm into a major breakdown. Layered on top of that, the emergency playbook that starts with Safety Comes First is a reminder that resilience is not just about hardware. It is also about having a plan for what you and your family will do when, not if, one of these systems fails under extreme stress.

Supporting sources: These US cities face the greatest severe weather threats, data ….