Freeze warning: protecting pipes and your home policy

A freeze warning means something different in Boise than in Phoenix, and the difference is part of the risk. In Idaho, northern Utah, Reno and Flagstaff, houses are built for cold, with pipes inside heated space, and the danger comes when the heat fails or the house sits empty. In the low desert of Arizona and southern Nevada, a hard freeze arrives only on a handful of nights, but houses there often run water lines through attics, exterior walls and uninsulated garages, and pool equipment and backflow valves sit exposed in the yard.

Either way, the homeowners policy asks the same question after a burst pipe: did the owner take reasonable care? This article explains how pipes actually fail, what the freezing provisions say, how the answer changes for renters, condo owners and small businesses, and what to do before, during and after a cold night.

How a frozen pipe bursts

Ice rarely splits a pipe where it forms. As water freezes it expands and creates a blockage, and the continued freezing pushes pressure along the pipe toward the next closed faucet or valve. The pipe fails in that trapped section, often a few feet from the ice, sometimes inside a wall where nothing looks frozen. And it usually leaks only after the ice thaws, which is why burst pipes are discovered mid-morning or days later when the owner comes home.

That sequence shapes the precautions. Keeping the whole length of pipe above freezing matters more than warming one spot, and relieving pressure by letting a faucet drip on the vulnerable line gives the pressure somewhere to go.

What the policy says about freezing

Standard homeowners forms cover sudden and accidental water discharge from plumbing, including from a pipe that bursts after freezing. The exception is the freezing condition: damage caused by freezing of plumbing, heating, air conditioning or sprinkler systems is excluded while the house is vacant, unoccupied or under construction, unless the owner used reasonable care to maintain heat in the building or shut off the water supply and drained the systems. The exact wording varies by form and carrier, but that structure is common.

Several details follow from the wording. The damage the escaping water causes, to floors, drywall, cabinets and contents, is the main covered loss. The cost of tearing out and replacing a wall or ceiling to reach the pipe is usually paid. The repair of the burst pipe itself is often excluded as the system that failed, depending on the form. A separate freezing exclusion typically removes damage from freezing, thawing and the pressure of ice to fences, pavement, patios, foundations, retaining walls, docks and swimming pools. And a policy's vacancy clause can reduce or remove water damage coverage once a house has been empty beyond a stated number of consecutive days.

Suppose a house in Meridian is left for a week over the holidays with the thermostat turned down to save energy, a pipe in an exterior wall bursts and $35,000 of water damage results. If the thermostat was set to a reasonable temperature and the furnace ran, the claim is generally paid less the deductible. If the owner switched the heat off and left the water on, the carrier may decline under the freezing condition. These figures are hypothetical; the thermostat setting is not.

Renters, condos, rentals and businesses

A renter's policy covers the tenant's belongings when a pipe bursts; the landlord's policy covers the building. A tenant who turns the heat off or leaves a window open in freezing weather may face a claim from the landlord's carrier seeking to recover the repair, which the renter's personal liability coverage generally responds to. Landlords with vacant units between tenants should treat each unit as an empty house and keep heat on or drain the lines.

In a condo, water from one unit damages others. The association's master policy covers the building as its documents define it, the HO-6 covers the owner's interior and contents, and loss assessment coverage pays an owner's share of the association's deductible when it is passed on.

Small businesses carry the same risk with larger consequences. A frozen fire sprinkler line in an unheated warehouse or shop can soak inventory and equipment; commercial property forms treat freezing of sprinkler systems in a similar way, conditioned on maintaining heat. Spoiled refrigerated stock after a power failure needs spoilage coverage, and the time closed for drying out is business income loss.

Before the freeze

When the forecast turns, these steps take less than an hour.

• Disconnect garden hoses and close interior shutoffs to exterior faucets; cover hose bibs with insulated caps.
• Wrap exposed pipes in the attic, garage and crawlspace, and backflow preventers and pool equipment outside. In the desert, run the pool pump overnight if the manufacturer recommends it.
• Open cabinet doors under sinks on exterior walls so room heat reaches the pipes.
• Let a faucet on the most exposed line drip, hot and cold, to relieve pressure.
• Keep the thermostat at a steady, reasonable temperature day and night, including when away.
• Find the main water shutoff and make sure it turns. Everyone in the house should know where it is.
• If leaving the house empty, either keep heat on and ask someone to check it daily, or shut off the main, open faucets and drain the lines. Note which you chose and when.

During and after

If a faucet produces a trickle or nothing on a cold morning, assume a pipe is frozen. Leave the faucet open, warm the pipe gradually with a hair dryer, a space heater kept at a safe distance or warm towels, and never use an open flame. If a pipe has already split, shut off the main before thawing it, because the leak starts when the ice melts.

If water is escaping, shut the main, turn off electricity to wet areas if it is safe to reach the panel, and start removing water. The policy expects reasonable steps to limit the damage, and the carrier generally reimburses emergency water extraction, drying equipment and temporary repairs. Photograph the damage, the burst pipe and the thermostat setting before anything is moved, and keep the failed section of pipe. Report the claim promptly, because water damage grows by the day and mould that develops from a delay can fall under a sublimit or an exclusion.

Suppose the family in the earlier example finds the leak within a day and calls a water mitigation company, whose invoice comes to $6,000. That cost is usually part of the covered loss. If the same leak had run unnoticed for three weeks, the added mould remediation of, for example, $10,000 might be capped by a mould sublimit. These are hypothetical figures.

The decision points

Three choices matter. Whether the house, rental or business will be protected by heat or by draining whenever it is left empty in winter, and whether someone checks it. Whether a water shutoff device or a temperature and leak sensor is worth installing; several carriers offer credits, and the device stops the loss at the first gallon. And whether the policy's water damage, mould and vacancy terms fit how the property is used, especially for a second home or a house owned by snowbirds who winter in Arizona.

If all three are settled, no policy change is needed. If not, we read the freezing, vacancy and mould provisions on your declarations page and compare them across the carriers we represent in Arizona, Nevada, Utah and Idaho at no cost, and we say so when your current policy already fits.