The short answer
Your water company, such as Thames Water, Affinity Water or SES Water, is responsible for the water main and the pipe up to your property boundary, usually where the outside stop tap or meter sits. You are responsible for the supply pipe from the boundary to your home, and for all the plumbing inside. If the pressure problem starts on their side, they must fix it. If it starts on yours, you need a plumber.
Who owns which pipe?
| Pipe | Who is responsible |
|---|---|
| Water main in the street | Water company |
| Communication pipe, from the main to your boundary | Water company |
| Supply pipe, from the boundary to your home | Property owner |
| Internal pipes, stopcock, taps and valves | Property owner |
| Shared supply pipes in older terraces | Usually shared between the owners |
Signs the problem is the water company's
- Neighbours have low pressure too.
- Your supplier's website shows works or a burst in your area.
- Pressure is low at the outside stop tap as well as inside.
Signs the problem is yours
- Only your home is affected.
- Pressure is fine at the outside stop tap but weak inside.
- There are damp patches on your drive, garden or floors.
- Pressure drops when two taps run at the same time.
How to report low pressure to your water company
- Check their website or app for known incidents.
- Note when the pressure is low and for how long.
- Call or report online, giving your address and what you have noticed.
- Ask whether your area falls below their pressure standard. Water companies have a minimum pressure level set under Ofwat rules.
When to call a plumber
If the water company finds no fault on their side, the problem is on your supply pipe or inside your home. A plumber can measure pressure and flow, trace leaks and replace restricting valves or old pipes. Many landlords and homeowners in older London terraces find a shared or undersized supply is the cause.
Related service: water pressure and supply repairs. Further reading: Ofwat guidance for household customers.
A few common questions
Is low water pressure the water company's responsibility?expand_more
Only if the cause is on their network, such as the main or the pipe up to your property boundary. If neighbours are also affected, or there are works nearby, contact your water company. If only your home is affected, the cause is more likely on your supply pipe or internal plumbing.
Who is responsible for the water supply pipe?expand_more
The property owner is usually responsible for the supply pipe running from the boundary, often where the outside stop tap or meter sits, to the home. The water company looks after the main and the communication pipe up to that boundary. Shared supplies in older terraces are usually shared between owners.
How do I complain about low water pressure?expand_more
Check your water company's website for incidents first. Then contact them by phone or online, giving your address and details of when the pressure is low. Ask whether your area meets their minimum pressure standard. If you are unhappy with the answer, you can escalate the complaint.
Can a plumber fix low water pressure?expand_more
Yes, if the cause is on your side. A plumber can open or replace a restricting stopcock, clear blocked valves, find and repair supply pipe leaks and upgrade old iron or lead pipes. They can also measure pressure and flow to show whether the water company's supply is the real problem.
Why is my pressure low in a flat?expand_more
Flats often share supply pipes and stacks, and upper floors get less pressure because water has to rise further. A narrow shared supply, a part-closed valve or a failing pump can all reduce pressure. A plumber can test your flat's supply and explain whether the fix is inside your flat.