Keep warm room air reaching the pipes
EPA recommends opening cabinets so warmer room air can reach uninsulated pipes under sinks or near outside walls. First move cleaners and household chemicals somewhere children and pets cannot reach. Avoid sharply reducing the heat overnight during a cold spell.
Philadelphia Water Department guidance calls for keeping the water-meter area above 40°F. That is a target for the meter’s surroundings—not a recommended thermostat setting for the entire occupied house.
Look for the cold exposure without opening walls
Start with kitchen and bathroom plumbing beside the outside wall, then look at safely accessible basement supply pipes. PWD specifically identifies exterior-wall pipes and pipes in unheated areas as priorities for insulation. Check nearby windows for broken glass, gaps, or noticeable drafts.
PWD recommends repairing broken exterior windows, using window plastic, and caulking windows near meters and pipes. Have accessible water pipes in unheated areas properly insulated. Keep this inspection visual: do not remove wall finishes to find a concealed pipe.
Make a short record for a contractor: which sink has trouble, where the pipe is visible, whether a nearby window leaks air, and whether opening the cabinet changes how cold the space feels. These observations help frame the investigation without pretending to identify a hidden defect.
Set a cold-night routine before flow disappears
PWD advises taking precautions when forecasts call for temperatures below 32°F, especially for two days or more. Check vulnerable faucets for normal flow before bed and again in the morning; reduced flow can be the first sign of freezing.
For pipes that have frozen before, or are in a space you cannot keep warm, PWD recommends letting the faucet drip. Its cold-weather guidance also recommends a trickle overnight during extremely cold weather. Target the vulnerable fixture rather than assuming every faucet needs to run.
Before the next cold spell, ask a licensed plumber which faucet serves the problem pipe and how to protect that particular run. Do not wait until it has stopped flowing to work out the pipe route.
Separate a vulnerable branch from a wider outage
If flow weakens, note whether the problem affects one fixture, several fixtures, or the entire house. Tell the plumber whether the hot side, cold side, or both are affected. These are useful diagnostic observations, not proof that a particular concealed section is frozen.
If the house has no water, PWD recommends checking whether a neighbor has service. Several homes without water may indicate a water-main problem; if neighbors have water, the problem is more likely within your own plumbing. Contact PWD about a suspected public-system outage and a licensed plumber about suspected frozen household piping.
Do not assume a faucet that starts working again means everything is sound. PWD advises checking for cracked or damaged pipes after thawing.
Know the shutoff—and never use flame
Locate the house-side water shutoff near the meter before an emergency, and keep access clear. Ask a plumber to identify it if you are unsure. PWD directs homeowners to use that valve if a household pipe is damaged.
Never use a torch or other open flame to thaw plumbing. EPA explicitly warns against torch thawing. For a suspected freeze inside an exterior wall, call a licensed plumber rather than opening the wall or improvising a heating setup.
Report a leaking or damaged meter to PWD. Repairs to household piping are a separate responsibility; PWD’s cold-weather guidance directs owners to a licensed and registered plumber.
Ask for a lasting repair and the permit plan
For recurring trouble, ask the plumber to investigate why the run stays cold: Is it exposed to a draft, inadequately insulated, or located where room heat cannot reach it? Request a written scope distinguishing immediate freeze protection from any proposed pipe relocation or wall work.
In Philadelphia, plumbing installation, alteration, replacement, and repair generally require a Plumbing Permit, although specified minor repairs and stopping leaks are exempt. A licensed master plumber must oversee permitted plumbing work. Ask who will obtain the permit, whether the work qualifies for an EZ permit, and which inspections are required before repaired piping is concealed.
Cabinet opening and overnight dripping should not become the only plan for a repeatedly freezing pipe. Ask what correction will address its exposure while keeping the home occupied.
Related HomeFix guides: insulating pipes in a rowhome basement · outdoor faucet leaks inside the wall after a freeze · furnace condensate line freeze or backup · low water pressure at one faucet.