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uk Home & property emergencies sudden low water pressure • water pressure dropped suddenly • no water pressure in house • water pressure very low • suspected major water leak • possible burst pipe • hidden water leak • water meter spinning • stopcock shut off • internal stop tap • leak on supply pipe • leak outside property • water company emergency leak • flooding risk from leak • leak under floorboards • leak in walls • leak in loft tank • shared building water leak • landlord water leak emergency • water pressure drop shower

What to do if…
your water pressure drops suddenly and you suspect a major leak

Short answer

Stop using water and turn off your internal stop valve (stopcock) to limit damage, then do a quick meter/neighbour check and contact the right help (water company for supply/outside issues; plumber/landlord for internal leaks).

Do not do these things

  • Don’t keep running taps “to see if it comes back” — that can increase damage if a pipe has failed.
  • Don’t ignore warm/damp patches, hissing sounds, or water staining because you “can’t see water” yet.
  • Don’t touch electrics or plug/unplug anything if there’s any sign of water near sockets, lights, the consumer unit, or appliances.
  • Don’t start breaking walls/floors or digging outside in a panic.
  • Don’t tamper with communal/shared pipework in flats/managed buildings — isolate what you safely can and alert building management.

What to do now

  1. Stop all water use immediately.
    Turn off taps, washing machine/dishwasher, showers, outside taps/hoses, and any irrigation timers.

  2. Turn off your internal stop valve (stopcock).
    It’s often under the kitchen sink, near where the mains pipe enters, or in a downstairs cupboard. Turn clockwise to close.
    If it won’t fully close, don’t force it to the point of breaking — move on to the next steps and contact help promptly.

  3. If you can access your water meter, do a quick “is it still moving?” check.
    With all water use stopped and your stopcock as closed as you can get it, note the meter reading (or movement). Check again after a short wait (about 10–30 minutes).

    • Any continued movement/increase suggests water is still flowing somewhere (often a leak, or the stopcock not fully closed).

  4. Scan for the most dangerous signs (30–60 seconds).
    Look/listen for hissing/rushing water sounds, fresh damp patches, bubbling paint, sagging ceilings, wet/musty smells, or water near electrics.
    If water is near electrics: keep people out of that area. Only if you can do so safely and while staying completely dry, switch off power at the consumer unit; otherwise, keep clear and get help.

  5. Check whether it’s likely your property or the wider supply.
    Ask a neighbour in the same building/street if they’ve also lost pressure. If several homes are affected, it may be a network issue or burst main.

  6. Contact the right help based on what you found.

    • If multiple homes are affected, or you suspect a burst main or leak in the street/outside: report a possible burst main/low pressure to your water company via their emergency reporting route.
    • If the meter suggests continued flow, or you have damp/flooding signs inside: contact an emergency plumber.
    • If you rent or it’s a managed block: contact your landlord/letting agent/building management immediately and tell them you’ve shut the stopcock and suspect a major leak.

  7. If you couldn’t shut the stopcock fully, don’t wait to “see.”
    Tell the water company/plumber/landlord the stopcock won’t fully close. If you know where a boundary/external stop tap is and it’s safe to access, you can mention that location — otherwise leave it to the professionals.

  8. Limit damage while you wait (only if safe).

    • Put buckets/towels down, move valuables/electronics up high, and open cabinet doors where pipes run.
    • If a ceiling is bulging with water, keep people out of the room (collapse risk) and keep the water supply off.

  9. Record what happened (quickly).
    Take photos/video of meter movement/reading, any damp/flooding, and the time you noticed the pressure drop.

What can wait

  • You don’t need to find the exact leak location right now.
  • You don’t need to decide about repairs, claims, or who pays until the water is stopped and the situation is stable.
  • You don’t need to start drying/cleaning aggressively until any active leak is confirmed stopped.

Important reassurance

A sudden pressure drop can feel alarming because it’s sudden and unfamiliar. Turning off the stopcock (as far as it will go) and checking the meter/neighbours are fast actions that reduce harm and give clear information to the right people.

Scope note

These are first steps to stabilise the situation and prevent rapid damage. After the leak/supply issue is confirmed, next steps may involve a plumber, your landlord/building manager, your insurer, and/or your water company’s leakage process.

Important note

This is general emergency guidance, not a substitute for a qualified plumber or your water company’s instructions. If you think there is any electrical danger, prioritise safety and keep clear of affected areas.

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