What causes low water pressure in London homes?
Low water pressure is usually caused by mains supply issues, scale build-up in old pipework, a faulty pressure reducing valve, or an undersized cylinder.
Common Causes of Low Water Pressure
- Mains supply pressure — some London areas naturally have lower mains pressure, especially upper floors of period conversions
- Scale build-up — hard water causes limescale to restrict old galvanised or copper pipework
- Faulty pressure reducing valve (PRV) — regulates incoming mains pressure and can fail over time
- Undersized or ageing cylinder — vented cylinders and old combi boilers can struggle to deliver strong flow to multiple outlets
- Partially closed stopcock — sometimes simply a valve that hasn't been fully opened
When to Call an Engineer
If pressure has dropped suddenly, it's often a boiler or PRV fault. If it's been gradually declining over months, scale or pipework corrosion is more likely. Our engineers can diagnose the cause and recommend a fix — from cylinder upgrades to a water softener installation.
Reviewed by RARE Plumbing London Engineering Team — Gas Safe registered engineers serving prime London since 2013.
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