Low Water Pressure at Home: Common Causes and What to Check

First, work out if it's the whole house or one outlet

This is the most useful check you can do. If only one tap or shower is weak, the problem is almost always at that fitting. If every cold tap is poor, look at the supply coming into the property.

Do a simple flow test at the kitchen cold tap, which is usually fed straight from the mains. Open it fully and time how long it takes to fill a 1 litre jug. Under 6 seconds (about 10 litres a minute or more) is reasonable for most homes. If it takes 10 seconds or longer, your flow is low, and a combi boiler will struggle to give you a decent hot shower.

• One outlet weak: check aerators, shower heads, hoses and isolation valves
• All hot taps weak but cold fine: suspect the boiler, cylinder or tank
• Everything weak: check the stop tap, supply pipe and neighbours' supply

Causes at a single tap or shower

Leicestershire has hard water, and limescale builds up fast. The small mesh aerator on a tap spout and the holes in a shower head can clog within a year or two, cutting flow noticeably. Unscrew them and soak them in white vinegar or descaler overnight.

Other culprits include a small isolation valve (the screw-slot valve on the pipe under a sink or toilet) that has been left half closed, a kinked shower hose, or a failing thermostatic mixer cartridge. Mixer cartridges often need replacing rather than cleaning.

Causes affecting the whole house

Start with the internal stop tap, usually under the kitchen sink. Make sure it's fully open, turning anticlockwise until it stops. Old stop taps can also wear inside and restrict flow even when fully open.

Many Wigston homes, especially Victorian terraces and 1930s semis, still have old supply pipes. A lead or galvanised steel pipe from the boundary to the house can narrow inside over decades, and some older properties share a supply pipe with next door, so pressure drops when they run water too.

A hidden leak on the supply pipe is another cause. Turn off every tap and appliance, then watch the water meter. If the dial keeps moving, water is escaping somewhere.

Finally, it may not be your pipework at all. Severn Trent supplies this area, and pressure can dip at peak times or during work on the network. Their website shows planned works and known issues by postcode.

Hot water pressure problems

If only the hot water is weak, the cause depends on your system. With a gravity-fed system, pressure comes from the height of the cold tank in the loft above the outlet. A shower on the first floor may only get 0.1 to 0.2 bar, which is simply how the system is designed. A shower pump or an unvented cylinder can help, but an unvented cylinder needs good mains flow first.

With a combi boiler, hot flow is limited by the incoming mains and the boiler's output. A scaled plate heat exchanger or a blocked filter on the cold inlet can also reduce flow.

When to call a plumber and what it might involve

Cleaning aerators and checking valves is safe DIY. It's worth getting a plumber in if the stop tap is seized, you suspect a leak, or you think you have a lead supply pipe. Lead pipes are worth replacing for health reasons as well as pressure.

Costs depend heavily on the job. Replacing a stop tap or mixer cartridge is usually a short visit. Renewing a supply pipe from the boundary means digging, so the price depends on the length, what's on top (lawn, block paving or concrete) and access. Severn Trent sometimes offers help with lead pipe replacement, so ask them before you commit. A good plumber will test the pressure and flow properly first, so you only pay to fix the actual cause.