Freezing nights are rare enough in southern Nevada that much of the local plumbing is installed as if they never come. Water lines run through attics. Softeners and pressure regulators sit outside in side yards. Irrigation backflow devices stand fully exposed in front lawns. That works for most of the year. It stops working on the handful of winter nights when the valley floor drops into the 20s, especially in the west valley, parts of Henderson, and low spots near the edges of town where cold air settles.
A freeze never damages every pipe equally. It finds the parts with the least insulation, the most wind exposure, and water trapped with nowhere to go. Ice takes up about 9 percent more space than liquid water. A fitting that is completely full has no room for that growth. Brass bodies crack, plastic housings split, and copper bulges at its weakest seam. Often nothing leaks until the line thaws the next afternoon.
Fall is the practical window to look at these spots. Days are still mild, and landscapes need far less water. The Southern Nevada Water Authority moves most properties to one assigned irrigation day per week from November through February, so the irrigation side of a home’s plumbing can be protected without working around a busy watering schedule.
Freeze damage tends to show up at inconvenient hours, usually on a weekend morning when the sun hits a split fitting and water starts spraying. ProServ keeps a Las Vegas plumber on call around the clock, and its team handles water line repair, pipe replacement, water heater service and routine plumbing maintenance throughout the valley. A pre-winter visit can spot exposed lines and worn valves before the first cold snap. For anyone who would rather not hunt for a number at 6 a.m. in January, saving ProServ’s emergency line, 702-656-4500, now is the simplest step to take before winter.
1. The Backflow Preventer in the Front Yard
The pressure vacuum breaker that feeds most valley sprinkler systems is the classic freeze casualty. It sits a foot or more above the ground, is made of brass and thin internal parts, and holds standing water year round. One night in the mid 20s can crack the body or pop the bonnet. Insulated pouches made for these devices cost little and slip on in seconds. Leave the pouch on through February, because the coldest nights often come late. If the irrigation system is shut off entirely for winter, the device should also be drained using its test cocks.
2. Hose Bibs With Hoses Still Attached
A frost-free hose bib keeps its actual valve deep inside the wall, where house heat protects it. That design only works if water can drain out of the spout. A garden hose left connected traps water in the stem. The ice then splits the pipe inside the wall, where nobody sees it until the drywall stains or the stucco weeps. Disconnect every hose before the first cold night. Older bibs that are not frost free, which are common on houses built before the 1990s, are worth covering with foam caps.
3. The Outdoor Pressure Regulator
Many valley homes have a pressure-reducing valve mounted outside near the front hose bib, where the service line enters the house. This valve protects fixtures and appliances from high street pressure, and it is almost never insulated. Freezing can crack its bell housing or damage the diaphragm inside. The damage is not always visible. Signs include pressure that suddenly spikes, banging pipes, or a relief valve on the water heater that starts dripping. Wrapping the regulator and the short pipe sections around it takes minutes and protects a part that costs far more to replace.
4. Water Lines Running Through the Attic
Because so many local homes are built on concrete slabs, water lines often run overhead through the attic instead of under the floor. On a freezing night, an attic can drop close to outdoor temperature. The weak spots are lines laid on top of the ceiling insulation rather than buried beneath it, and runs near gable vents or soffits where wind blows in. During an attic check, look for pipe sections left exposed above the insulation. On the coldest nights, leaving cabinet doors open along exterior walls lets indoor heat reach nearby lines.
5. A Water Softener Mounted Outside
Because local water is so hard, softeners and filters are common. Many are installed in side yards to save garage space. The control valve head is usually plastic, and the bypass assembly holds standing water. Both can crack in a hard freeze. Brine tanks handle cold better, but the lines feeding them do not. An insulated enclosure or a fitted cover helps. On an extended cold night, some owners put the system in bypass and drain the head, following the manufacturer’s instructions.
6. Tankless Heaters and Garage Water Heater Lines
Outdoor tankless water heaters include built-in freeze protection, but it only works while the unit has power and gas. A power outage on a cold night leaves the heat exchanger exposed. Manufacturers usually include a drain procedure for that case. Water heaters in garages face a smaller risk. Still, the inlet and outlet pipes near an uninsulated garage door, along with the relief valve discharge line that runs outside, can freeze. Foam pipe sleeves on exposed sections and a weather strip on the garage door help keep that corner warmer.
7. The Main Shutoff Nobody Has Turned in Years
The last weak spot is not a pipe. It is the valve you need when any of the other six fail. Main shutoffs that have not been turned in years often seize, especially gate valves in older homes, where the internal gate can break off when forced. Find the main shutoff now, along with the meter-side shutoff in the box at the curb, and confirm both actually turn. A valve that only closes partway is worth replacing with a quarter-turn ball valve before winter, not during a burst.
After the Thaw
Some freeze damage leaks slowly instead of bursting. Once temperatures recover, turn off every fixture and watch the leak indicator on the water meter for fifteen minutes. If it moves, something is running. That check matters more than it may seem. The EPA’s WaterSense program estimates that household leaks can waste nearly 10,000 gallons a year in an average home, and a hairline crack in an attic fitting fits that description exactly. A quick meter test after each hard freeze catches these leaks while they are still small.
