Why Does My Faucet Sputter and Spit Air After the Water Was Shut Off — and Is the Water Safe?

Why does my faucet sputter and spit air after the water was shut off?

Because air got into the pipes while they were empty. When the water is off and taps are used, the pipes drain and air takes the water’s place; the City of Bellevue’s water utility tells customers not to use any water during a shutdown for exactly that reason, and warns that after service is restored air may make its way into the plumbing [1]. When the water comes back, that air is pushed out ahead of it at the first tap you open — the cough, hiss and spit you hear.

Citizens Energy Group, a water utility, names the most common cause of sputtering, banging or hammering from air in the lines: repair work on the water mains that carry water to homes [2]. So a main break or a repair in the street can send air into a house even if nobody inside turned a tap. The same thing happens on a smaller scale when the house valve is closed for a repair inside — see our article on where the main water shutoff valve is for how to close and reopen it.

Sputtering on its own does not mean anything is wrong with the water. It means there is still air between the meter and the tap. What matters for safety is covered further down: whether your utility has issued a boil-water notice.

How do I get the air out of my water lines?

Run the cold water and let the air push itself out. Bellevue’s utility says to open cold faucets slowly and let the water run for a few minutes, and recommends a bathtub or an upstairs faucet for it [1]. Citizens Energy says to turn on all the taps; the air should leave within a few minutes, though it can take up to 15 [2]. In a one-storey Florida house there is no upstairs, so the bathtub is the tap to start with.

Advice on the order varies. Plumbing websites we looked at disagree — some start at the lowest tap, some at the highest. We follow what the utility says: a tub or an upstairs tap first, cold only, opened slowly [1]. The drawing below shows that order on a typical one-storey house.

Take the aerators off first if you can. Delta’s instructions for flushing a faucet say to remove the aerator and its sealing gasket, run the water, then put the aerator back, and that it is a good idea to do this each time the water has been turned off for repairs [6]. Grit then goes down the drain instead of into the screen.

Two things to avoid while the water is still off: using water at all, which lets more air in, and opening hot taps — Bellevue warns that draining the water heater could expose its heating elements and damage the heater, electric, gas or on-demand [1]. If air is still coming out after 15 minutes, Bellevue says to call the utility [1].

Why is my tap water cloudy or milky white after the water comes back on?

Tiny air bubbles. The U.S. Geological Survey explains that cloudy or “white” water is caused by air bubbles: water under pressure in the pipes holds more air than water at the open tap, and when the pressure drops the extra air comes out as bubbles, much like opening a soda [3]. It calls the effect completely harmless and says to let the water stand in an open container until the bubbles disappear [3]. Cold water holds more air than warm water, which is why the USGS says it shows up more in cold weather [3].

There is a simple check. The UK’s Drinking Water Inspectorate says to fill a glass and watch it: water that clears from the bottom up is trapped air, and that is not harmful to health [4]. It lists the return of a main to service after work on the network as one of the times this happens, and says to contact the water supplier if the cloudiness lasts more than 24 hours or the water tastes or smells unusual [4].

Brown or rusty water is different: that is sediment stirred up by the change in flow, not air. Bellevue says to let the cold water run for a minute or two and it should clear, and to call the utility if it is still discoloured after 15 minutes [1]. In Pinellas County, the county asks customers to report cloudy or discoloured water after a boil-water notice has ended [8].

Why is there grit in my faucet aerator after the water was off — and how do I clean it?

Because the surge that refills the pipes carries loose particles with it, and the aerator screen at the end of the spout catches them. Denver Water says it is important to remove and clean aerators after a water main break, a main replacement or a service-line replacement, because dirt particles get trapped in them [7]. Bellevue ties reduced flow at a faucet after a shutdown to rust particles in the aerator screens, and says to remove the screen to restore full flow [1]. If only one tap is weak and the rest of the house is normal, it is that aerator or that faucet, not the main — our article on why water pressure is low covers the whole-house causes.

Moen’s instructions sort aerators by how they come off [5]:

• Exposed, threaded on the outside: unscrew it clockwise; threaded on the inside: counter-clockwise [5]
• Concealed, round with indentations: use the removal key supplied with the faucet and turn it counter-clockwise [5]
• Oval aerators: held by hex screws or simply pressed in; Moen lists the hex-wrench size for each version, and pulls the press-fit one straight out with needle-nose pliers [5]
• No visible aerator at all: some faucets have in-line filters at the end of each supply line under the sink; turn the water off, disconnect the line and rinse the filter [5]
• Soak the parts in vinegar for about five minutes, scrub with an old toothbrush and screw the aerator back on; wrap a rag round an exposed aerator before gripping it with pliers, to protect the finish [7]

Is the water safe to drink after the water was shut off?

Yes, unless your utility has issued a boil-water notice. Air and milky water are harmless [3][4]. The question is whether anything could have got into the public pipes while they lost pressure, and that is the utility’s call, not something you can see in the glass.

Florida’s Department of Health guidelines say a precautionary boil-water notice shall be issued when the pressure in any part of a water distribution system drops to zero or goes negative, and must be issued for a main break that is judged an imminent threat or may affect the water’s bacteriological quality; a main that is clamped while it stays full of pressurised water does not need one [10]. So a main break does not automatically mean a notice. The City of Tampa puts it in plain words: it issues one when a loss of water pressure may allow contaminants such as pathogens in, whether from a broken main, a loss of power or a scheduled repair outage [9].

A precautionary notice is not a finding that the water is contaminated. The Florida Department of Health in Hillsborough County separates the precautionary notice, issued when contamination is possible, from the mandatory one, issued when contamination is confirmed [12].

If only your own house valve was closed for a repair inside the house, the public mains never lost pressure; the notice rules above are written for the distribution system [10]. That is our reading of the guidelines, not a separate rule — in that case flush the cold taps as described above.

What should I do during a precautionary boil-water notice?

Boil water you will drink, cook with or brush your teeth with, or use bottled water. Pinellas County Utilities, the City of Tampa, the Florida Department of Health and the CDC all give the same boiling rule: a rolling boil for at least one minute [8][9][10][13]. The CDC adds: boil your tap water even if you filter it [13].

If you cannot boil — during a power cut, say — the Florida Department of Health and Tampa give a bleach method: 8 drops of unscented household bleach per gallon, mixed and left to stand 30 minutes, or 16 drops if the water is cloudy [9][10]. Pinellas County gives it as ⅛ teaspoon per gallon and notes it is less effective than boiling [8].

Showering is allowed, but the CDC says not to swallow the water when bathing or showering, and to take extra care with babies and young children — a sponge bath reduces the chance of swallowing [13]. Tampa says the notice usually stays in effect for about two days while bacteriological tests are run [9]; the state guidelines require at least one day of satisfactory samples to lift it, and a second day of sampling after a main repair [10].

What do I do after the boil-water notice is lifted?

Flush the cold water through the house. Pinellas County Utilities asks for cold water at every tap for at least five minutes immediately after the notice is lifted, and for one batch of ice from the ice maker or refrigerator dispenser to be thrown away [8]. It says that flushing the cold taps is enough: there is no need to replace or clean refrigerator or under-sink filters, and no need to flush the water heater separately [8].

Other Florida guidance asks for different steps, so follow the notice your own utility hands out. The Florida Department of Health’s bulletin for food businesses calls for five minutes at each tap and throwing away the first binful of ice [11]. The Department of Health in Hillsborough County asks households to run all the cold taps at once for one minute at full flow, make and discard three batches of ice, regenerate a water softener and change refrigerator filters [12].

If the water is cloudy or discoloured once the notice has ended, Pinellas County asks you to call its customer service line at (727) 464-4000 [8].

When should I call the utility — and when a plumber?

Call the utility when the problem is the water itself or the whole street: air still coming out after 15 minutes, or brown water that has not cleared after 15 minutes [1], cloudy water after a notice has ended [8], or a question about whether a notice covers your address [9]. Call a plumber when the problem is inside the house. In our experience that means:

• one faucet still sputters or runs weak after its aerator is cleaned — Delta’s next step is to take out the faucet’s internal parts and flush the supply, which is a job for someone with the right parts at hand [6]
• the house valve will not open fully again after the outage
• a leak at a fitting, a supply line or the water heater once the water came back
• banging in the walls that continues after the air has cleared
• air that keeps coming back days later with no work in the street

What this means in Clearwater and across Tampa Bay

Boil-water notices are issued by your water utility under the Florida Department of Health’s statewide guidelines [10], so where you live decides who tells you. Clearwater runs its own water utility and posts notices and repair updates at MyClearwater.com/BoilWater; in October 2026 it put a handful of homes under a boil-water notice after a contractor struck a 6-inch main, and removed it three days later once repairs were complete [14]. Pinellas County Utilities lists any active notice on its boil-water page and takes calls at (727) 464-4000 [8]. The City of Tampa hangs the notice that lifts a boil-water order on the front door of each affected home or business, and its call centre is (813) 274-8811 [9].

The kitchen faucet at the top of this page is in a Clearwater home: a brushed-gold pull-down faucet running a clear, steady stream into a farmhouse sink. If a tap in your house still sputters, runs weak or leaks after the water has come back on, call 727-470-7126 and tell us which one and what it does.

FAQ

Sources

We review and cite. We do not reproduce a paper or a manual — follow the links for the originals.

1. [1]Water Main Shutdowns — City of Bellevue Utilities (Washington) · 2024Government or standards body · “What to do after a shutdown”: do not use any water (keeps air out of the plumbing), do not run water appliances, do not turn on hot water — draining the tank could expose heating elements and damage the heater (electric, gas, on-demand); “Air in your Plumbing”: after service is restored air may enter the plumbing; open cold faucets slowly and run a few minutes; a bath tub or upstairs faucet recommended; call after 15 minutes; “Rust-colored water”: run cold a minute or two, call after 15 minutes; “Reduced water flow”: remove the aerator screen to clear rust particles; undated page, © 2024; read 2026-10-26
2. [2]Cause & Solution for Air in Water Lines — Citizens Energy Group (water utility, Indianapolis) · 2026Government or standards body · sputtering, banging or hammering from air in the lines; most common cause is repair work to the water main distribution system; turn on all the taps; air should leave within a few minutes but could take up to 15; additional flushing may be required; undated, © 2026; read 2026-10-26
3. [3]Water Q&A: Why is my drinking water cloudy? — Water Science School · U.S. Geological Survey · 2019Government or standards body · cloudy (white) water is caused by air bubbles; solubility of air rises with pressure and falls with temperature, so more common in cold weather; completely harmless; let it sit in an open container until the bubbles disappear; dated 2019-06-20; read 2026-10-26
4. [4]White or Cloudy Water — Drinking Water Inspectorate (UK) · 2026Government or standards body · tiny air bubbles trapped in the water, often after supply has been shut off or a main is returned to service after work; glass test — clears from the bottom up; not harmful to health; contact the supplier if it lasts more than 24 hours or tastes or smells unusual; undated; read 2026-10-26
5. [5]Faucet Aerator Cleaning — Moen Incorporated (Moen Solutions) · 2026Manufacturer's manual · Type 1 exposed: male-threaded unthread clockwise, female-threaded counter-clockwise; Type 2 concealed: round with indentations — supplied removal tool, counter-clockwise; oval versions — 1/8, 5/64 or 7/64 in hex wrench, or press-fit pulled out with needle-nose pliers; Type 3 in-line filters at the end of each supply line on faucets with no visible aerator — turn water off, disconnect, rinse; undated, © 2026; read 2026-10-26
6. [6]What are the proper flushing procedures for a new faucet? How often should the lines be flushed? — Delta Faucet Company · 2026Manufacturer's manual · kitchen/lavatory: remove the aerator and black sealing gasket, run hot and cold mixed for two minutes, replace the aerator; a good idea each time the water has been turned off for repairs; if problems persist, shut off supplies, remove internal components and flush the supplies 30–60 seconds; undated, © 2026; read 2026-10-26
7. [7]The big benefits of cleaning and updating faucet aerators — Denver Water (TAP) · 2021Government or standards body · remove and clean aerators after a water main break, main replacement or service-line replacement — dirt gets trapped; rag round an exposed aerator before pliers; key for recessed aerators; soak in vinegar five minutes, scrub with a small brush; dated 2021-04-21; read 2026-10-26
8. [8]Boil Water Information — Pinellas County Utilities · 2026Government or standards body · no active notices on 2026-10-26; notices are a short-term precautionary measure; rolling boil at least one minute; bleach ⅛ tsp per gallon, 30 minutes, less effective than boiling; after the notice: cold water at every tap at least five minutes, one batch of ice discarded, no need to replace or clean refrigerator or under-sink filters, no separate water-heater flush; report cloudy or discoloured water to (727) 464-4000; read 2026-10-26
9. [9]Precautionary Boil Water Notices — City of Tampa Water Department · 2026Government or standards body · issued when a loss in water pressure may allow contaminants such as pathogens — broken main, power loss or scheduled repair outage; several days (typically two) while bacteriological tests run; rolling boil one minute; 8 drops bleach per gallon, 16 if cloudy; rescind notice hung on the front door; Utilities Call Center (813) 274-8811; updated 2026-03-31; read 2026-10-26
10. [10]Issuing Precautionary Boil Water Notices (Boil Water Notice Guidelines) — Florida Department of Health · 2006Government or standards body · notice shall be issued where pressure in any part of the distribution system is reduced to zero or negative; below 20 psi case by case, required if critical-use facilities are affected; main breaks when an imminent threat or may affect bacteriological quality; clamped main kept full of pressurised water needs none; rescission needs at least one day of satisfactory samples, second day of sampling still required after main repairs; rolling boil one minute; 8 drops bleach per gallon, 16 if cloudy; issued 1997, revised 2006; read 2026-10-26
11. [11]Industry Bulletin for Florida’s Food Industry: Boil Water Notice Guidelines (April 2026) — Florida Department of Health with FDACS, DBPR, APD, AHCA and DCF · 2026Government or standards body · “Rescinding the Boil Water Notice”: after it is lifted, run water five minutes at each tap; include ice makers (discard the first binful); filters to be replaced if the supplier detected bacteria or debris is seen; written for food businesses; read 2026-10-26
12. [12]Boil Water Notice (BWN) — Florida Department of Health in Hillsborough County · 2026Government or standards body · precautionary notice when contamination is possible, usually from a main break, system maintenance or plant problems; mandatory (Tier 1) when confirmed; after lifting: run all cold faucets at once for one minute at highest flow, three batches of ice discarded, softener regenerated, refrigerator filters changed; undated, © 2026; read 2026-10-26
13. [13]Drinking Water Advisories: An Overview — Centers for Disease Control and Prevention · 2024Government or standards body · boil water advisory: full rolling boil for 1 minute (3 above 6,500 ft); boil even if you filter it; bottled or boiled water for drinking, cooking and brushing teeth; do not swallow water when bathing or showering, care with babies and young children, consider sponge baths; dated 2024-03-04; read 2026-10-26
14. [14]Water Leaks, Breaks and Emergencies — City of Clearwater · 2026Government or standards body · contractor struck a 6-inch water main Oct. 5; Clearwater Public Utilities shut off water to repair; boil-water notice for five listed addresses; removed Oct. 8, repairs complete; updates at MyClearwater.com/BoilWater; published 2026-10-15; read 2026-10-26