When is it worth calling an emergency plumber?

A true emergency is anything that floods your home, cuts off your water, or sends sewage or gas where it should not be. Call right away if you have any of these.

• A burst pipe or major leak with flooding. Water spreads fast and ruins drywall, flooring, and framing within hours. Shut off the main valve and call.
• No water at all. A total loss of water can mean a broken service line, a failed valve, or a main break, and it needs prompt attention.
• A sewage backup. Wastewater coming up through drains, tubs, or floor drains is a health hazard and should not sit.
• An overflowing toilet you cannot stop. If shutting the supply valve behind the toilet does not stop the rise, you need help now.
• No hot water during a cold snap. In a Phoenix winter night this is more than a comfort issue, since cold pipes and an unheated home add risk.
• A gas smell. This is the most serious item on the list, and it is handled before anything else (see the next section).

The thread tying these together is active harm. A pipe that bursts at midnight will not wait until 8 a.m. to stop flooding your hallway. The faster the water stops, the less you spend on repairs later. The EPA's home maintenance guidance encourages homeowners to find and fix leaks promptly and even endorses leak detection and automatic shut-off devices for exactly this reason.

A suspected gas leak is not a plumbing call first. It is a leave-the-building call. Natural gas is odorless on its own, so utilities add a chemical called mercaptan that smells like rotten eggs or sulfur. If you smell that, or hear a hissing or roaring sound near a gas line or appliance, treat it as a leak.

The American Red Cross is direct about the order of steps. As their flood safety guidance puts it: "If you detect natural or propane gas, or hear a hissing noise, leave the property immediately... then call the fire department after you reach safety." Get everyone out, leave the door open behind you, and do not stop to gather things.

On your way out, do not do anything that could create a spark. Do not flip light switches, touch thermostats or appliance controls, use a phone inside, light a match, start a car, or open an electric garage door. Once you are at a safe distance, call 911 and Southwest Gas at 877-860-6020, which is staffed day and night whether you are a customer or not. Southwest Gas lists the warning signs of a leak as a rotten-egg odor, a hissing or roaring sound, dirt or water blowing or bubbling near a line, and dead or discolored plants over a buried line. Ready.gov gives the same core rule for gas safety: if you smell gas, leave and call from outside.

A plumber comes into this only after the gas is shut off and the area is cleared. A licensed gas fitter can then find and repair the line. Safety agencies come first, every time. For more on telling apart a gas smell from sewer gas, see our page on whether your house smells like gas or rotten eggs.

Plenty of plumbing annoyances feel pressing but cause no real harm overnight. These can wait for a normal daytime appointment, which costs less and lets you compare options.

• A single dripping faucet. Annoying, and worth fixing, but not an emergency. Still, do not ignore it for long: the EPA notes a faucet dripping at one drip per second wastes more than 3,000 gallons a year.
• One slow drain. A single sink or tub draining slowly points to a local clog, not a system failure. A plunger or trap cleaning often handles it.
• A running toilet. A toilet that keeps cycling wastes water and should be fixed soon, but it is not a reason to pay an after-hours rate.

The dividing line is whether the problem is contained. A drip lands in the sink. A slow drain still drains. A running toilet still flushes. None of them are flooding your home or cutting off your water, so they can hold until morning. Fixing them quickly still matters for your bill: the EPA's WaterSense program reports that household leaks waste nearly 1 trillion gallons of water nationwide every year, and the average home loses more than 9,300 gallons annually to leaks. Soon is good. Tonight is usually not required.

One caution: a small problem can grow into a real one. A slow drain that suddenly backs up into other fixtures, or a drip that becomes a steady stream, has crossed the line. Watch for that change and call when it happens.

Once you have decided you have a real emergency and made the call, your next job is to limit the damage. The single most useful move is to stop the water.

For a problem at one fixture, like a toilet or under-sink supply line, turn the small shut-off valve at that fixture clockwise to close it. For a burst pipe or a leak you cannot pin to one spot, shut off the main water valve for the whole house. Knowing where that valve is before an emergency saves precious minutes, so locate it now if you are not sure. See our guide on finding your main water shutoff for help. For a water heater leak, turn off its power or gas first, then close the cold-water inlet on top of the tank.

After the water is off, contain and document. Move valuables and electronics away from the water, lay down towels or buckets, and take photos for your insurance claim. If sewage is involved, keep people and pets away from it. These steps protect your home and your wallet while the plumber is on the way. For a full checklist, see what to do while waiting for a plumber.

After-hours and emergency calls carry a premium, so the goal is to pay it only when it earns its keep. Run the problem through three quick questions. Is anyone in danger? Is water actively flooding the home or has it stopped entirely? Is sewage or gas where it should not be? If you answer yes to any of them, call now. The cost of a midnight visit is small next to the cost of a flooded floor or a gas hazard.

If the answer to all three is no, you almost certainly have a problem that can wait for a daytime appointment. A drip, a single slow drain, or a running toilet falls here. Booking it for business hours lets you avoid the premium and gives you time to ask about the work, the parts, and the price before you commit.

When you are genuinely unsure, lean toward calling, especially for anything involving sewage or a possible gas smell. A reputable plumber would rather talk you through a situation on the phone than have you guess wrong about a backup or a leak. In Phoenix, where many homes sit on slabs and a hidden leak can travel before you ever see it, acting fast on the real emergencies is what keeps a bad night from becoming a bad month.