Low Water Pressure at Home? Safe Checks to Try First

Low water pressure at home is usually down to something simple, such as a part-closed stopcock, a scaled-up showerhead or several appliances running at once, but it can also be a hidden leak or a problem on the water company’s network. If you’re in Clare, Sudbury, Haverhill, Long Melford or a nearby Suffolk or Essex village, these safe checks will help you work out which it is before you book a plumber. If you suspect a hidden leak in a Sudbury home, see our leak detection in Sudbury page.

Low water pressure: work out where the problem is

Before you change anything, take a minute to notice the pattern. It tells you (and us) a lot:

• One tap or shower only usually points to that fitting, its aerator, showerhead or a part-closed isolation valve under it.
• Every cold tap in the house points to the incoming supply: the stopcock, a leak on your supply pipe, or the mains in your street.
• Hot water only points to the hot water system, such as a combi boiler, a cylinder or a shower mixer, and that needs a qualified engineer rather than DIY.
• Only at busy times (early morning or early evening) can simply be high demand, both in your home and across the local network.

Safe checks to try first

1. Ask a neighbour and check for local incidents. If next door has weak flow too, the cause is probably on the network. Check your water company’s website for supply problems in your postcode: that’s Anglian Water for most of our area, or Essex & Suffolk Water in parts of Essex and south Suffolk. Report it to them rather than calling a plumber.
2. Make sure your inside stopcock is fully open. It’s often under the kitchen sink, in a utility room, garage or under the stairs. Turn it gently anticlockwise until it stops, then ease it back a fraction. A stopcock that was left half-closed after a repair is a common cause of weak flow. Never use grips or force on a stiff valve; see our guide to finding and turning off your stopcock, and our note on a seized or leaking stopcock.
3. Look for signs of a leak. Damp patches on floors or ceilings, a hissing pipe, a soggy patch in the garden over your supply pipe, or a meter that keeps turning when nothing is running can all mean water is escaping before it reaches your taps. Our water meter leak check shows how to test this safely.
4. Reduce what’s running at once. Pause the washing machine, dishwasher, garden hose and any cistern that’s still filling, then test the tap again. If pressure recovers, demand is the issue rather than a fault.
5. Clean a weak showerhead or tap aerator. In hard-water areas like ours, limescale builds up fast. If you have an electric shower, switch it off at its isolating switch first. Unscrew the showerhead or tap aerator by hand, soak it in a descaler following the product label, rinse it and refit it. Never mix descaler with bleach or other cleaners, and don’t force a fitting that won’t turn.
6. Check any isolation valve under a single tap. If only one tap is weak, there may be a small valve on the pipe beneath it. A screwdriver slot in line with the pipe usually means open. If it’s stiff, leave it and call us.
7. If only the hot water is weak, leave the boiler to us. You can check the boiler’s display and, if it shows a fault, use the reset button once as your user manual describes. Don’t remove the boiler casing or adjust anything inside it. Only a Gas Safe registered engineer may work on a gas boiler, and you can check an engineer on the Gas Safe Register.

Things not to do

• Don’t fit a booster pump to the mains or alter the incoming supply yourself. Under the Water Supply (Water Fittings) Regulations 1999, some pumps and supply changes need the water company to be told or to give consent first, so they need proper assessment.
• Don’t dig up, open or force the outside stop tap or boundary box. It usually belongs to the water company and may need a special key. Read more about the outside stop tap.
• Don’t touch electrics near water. If a leak has tripped your RCD or a circuit breaker, you can reset it once, only from a completely dry position. If it trips again, leave it off and call a registered (Part P) electrician.

When to stop and call us

• Your neighbours have normal pressure, your stopcock is fully open, and your low water pressure carries on.
• Pressure dropped suddenly and you can see, hear or suspect a leak, or the meter keeps moving with everything off. Our leak detection service can trace it.
• Your stopcock or a tap isolation valve is seized, leaking or won’t open fully.
• Only the hot water is weak, or your combi boiler keeps showing a fault. Book a Gas Safe boiler repair visit.
• You have no water at all. Start with our guide no water in my house.

If pressure has stayed low for days and the problem isn’t in your home, report it to your water company so they can investigate their side.

Smell gas or suspect carbon monoxide? Leave the property, open doors and windows if it’s safe, don’t use light switches or naked flames, turn the gas off at the meter only if it’s safe to do so, and call the National Gas Emergency Service on 0800 111 999. Seek medical advice if anyone has CO symptoms such as headaches, dizziness or nausea.

Further reading

• Anglian Water: monitoring water pressure
• Anglian Water Core Customer Information
• Our domestic plumbing services

This is general safety guidance. If you’re unsure, stop and call a qualified engineer.