Low Water Pressure in Your Cardiff Home? Causes and Fixes

Weak showers and slow-filling baths usually come down to flow rate rather than pressure — and the two are worth separating.

Pressure vs flow Pressure is the force behind the water; flow is how many litres per minute actually arrive. A combi boiler needs decent flow to deliver a good shower. We measure both at the kitchen tap before recommending anything.

Common causes in Cardiff homes - **Old or narrow mains.** Some older Cardiff properties still have 15mm or lead supply pipes into the house. - **Shared supply.** Converted flats often share one incoming main between several homes. - **Partly closed stopcock.** Frequently the culprit after previous work — and a free fix. - **Blocked filters and aerators.** Scale in tap aerators and shower heads kills flow quickly. - **Failed pressure reducing valve.** Common where a valve was fitted for an unvented cylinder. - **Gravity systems.** A loft tank gives poor pressure to upstairs showers by design.

What actually fixes it Upgrading the incoming main to 25mm, replacing failed valves, descaling, or fitting a shower pump or accumulator on gravity systems. Occasionally the right answer is a different boiler or an unvented cylinder — but only after the flow test proves it.

Book a flow and pressure test in Cardiff: 07545 125168.