Low water pressure throughout the house: where to start
Quick answer
If water pressure feels low across the whole house rather than at just one tap, the cause is more likely to be your stopcock, mains supply, or a shared supply issue than a fault with a single fixture. Confirm it’s affecting every outlet before assuming anything else. If pressure has dropped suddenly, check for signs of a leak; if it’s a gradual, ongoing issue, a plumber can help investigate the mains supply.
Safety first
- If pressure suddenly drops to almost nothing, check for signs of a burst pipe or leak before assuming it’s a mains issue.
- Avoid making any alterations to your mains water connection yourself.
- If you’re in a flat or shared building, be aware that shared supply arrangements can affect diagnosis.
Full checklist: Safety guidance
What you may notice
- Every tap and outlet in the house has noticeably low pressure — may point to the mains supply, your stopcock, or a shared supply constraint.
- Pressure has dropped suddenly rather than gradually — worth checking for a leak or burst, which is a different situation from a slow decline.
- Pressure has been gradually getting worse over weeks or months — can be more consistent with a developing mains or supply issue.
- Only certain outlets are affected — this points to a local rather than whole-house cause — see our guide on low mains water pressure for more on telling these apart.
These are possible explanations, not a confirmed diagnosis. An engineer can confirm the exact cause on inspection.
Safe checks to make, in order
- Check pressure at several taps around the house. This confirms whether it’s genuinely affecting everywhere, rather than just the tap you happened to notice first.
- Check your stopcock is fully open. A partially closed stopcock, even by a small amount, can noticeably reduce pressure throughout the property.
- Ask neighbours if practical. If they’re experiencing the same issue, this can point towards a wider mains problem rather than something specific to your home.
- Look for any signs of a leak, such as damp patches, unusually wet ground outside, or your water meter running when nothing is in use. This helps rule in or out a burst or leak as the cause.
What you can do safely
- Checking pressure at multiple taps to confirm it’s a whole-house issue.
- Confirming your stopcock is fully open.
- Asking neighbours whether they’re experiencing the same issue.
- Checking your water meter for signs of ongoing usage when nothing is running.
When to call a professional
- Pressure has dropped suddenly with no obvious explanation.
- You suspect a leak, based on damp patches or meter readings.
- The stopcock is confirmed open but pressure remains low.
- You’re considering a pressure-boosting solution and want confirmation it’s actually needed.
What to tell the engineer
- Whether pressure is low at every outlet or just some.
- Whether the drop was sudden or gradual.
- Whether you’ve checked the stopcock is fully open.
- Any signs of a leak you’ve noticed, such as damp patches or meter movement.
FAQs
How is this different from low pressure at just one tap?
Whole-house low pressure points towards the mains supply or your stopcock, while a single affected tap is more often a local blockage, such as a clogged aerator. See our guide on low mains water pressure for the single-tap checks.
Could this be caused by work happening on my street?
Yes, water company works nearby can temporarily reduce pressure. Checking with neighbours or your water company’s website for reported works in your area can confirm this.
Is it worth buying a pressure booster pump?
Only once you’ve confirmed the cause is genuinely a persistent mains pressure issue rather than a stopcock or leak. A plumber can advise on whether a booster is suitable and compliant for your setup.
Should I be worried about a sudden pressure drop?
A sudden, significant drop is worth investigating promptly, particularly checking for signs of a leak or burst pipe, rather than assuming it will resolve on its own.
Leave a Reply