Troubleshooting
Low Water Pressure: Causes and What to Do
Low water pressure makes showers weak, taps slow and appliances inefficient. Here are the most common causes in Irish homes and what can be done about each.
Low water pressure
Low water pressure is usually simple to narrow down once you know whether it affects the whole house or just one outlet. That first check points you straight at the likely cause.
Start by comparing the flow at taps around the house. Poor pressure everywhere points to the incoming supply, the pressure reducing valve, or a leak in the main pipe, while a single slow tap is usually a blocked aerator or a partly closed isolation valve. If several homes on your street are affected at once, the problem sits with the Irish Water mains rather than your property. Once you have ruled out the easy causes, a plumber can test the pressure with a gauge and fix whatever is restricting the flow.
Diagnose it
How to Pin Down Low Pressure
Turn on taps in different parts of the house and compare the flow. If pressure is poor at every outlet, the issue is with the incoming supply, the pressure reducing valve, or a leak somewhere in the main supply pipe. If only one tap or shower is affected, the issue is localised, usually a blocked aerator, a partially closed isolation valve under the unit, or a failing tap cartridge.
A blocked showerhead or tap aerator is the simplest fix: unscrew it, soak it in white vinegar overnight, and refit. This restores flow in limescale-affected areas like Dublin, Kildare and Meath. If multiple houses on your street have low pressure at the same time, check the Irish Water outage map at water.ie, as the mains supply is their responsibility up to your boundary.
- Compare the flow at taps around the house
- Ask neighbours and check the Irish Water outage map
- Soak a blocked aerator or showerhead in white vinegar
- Check isolation valves under the unit are fully open
Why it happens
Common Causes of Low Water Pressure
Knowing the usual culprits helps you tell a quick fix from a job that needs a plumber.
Mains Supply Problem
Irish Water (Uisce Eireann) must maintain supply pressure up to your boundary. If several homes on your street are affected at once, the issue is theirs, not your property.
Failing Pressure Valve
The pressure reducing valve near the stopcock can stick or restrict flow as it ages, dropping pressure across the whole house until it is tested and replaced.
Limescale Build-Up
In hard water areas like Dublin, Kildare, Meath, Wicklow and Tipperary, limescale narrows the internal bore of pipes and fittings, so pressure drops slowly over years.
Corroded Steel Pipes
Older galvanised steel supply pipes corrode and narrow from the inside. Replacing them with copper or MDPE restores the flow they have lost.
Blocked Aerator
When only one tap or shower is weak, the cause is usually a limescale-clogged aerator or showerhead, or a partly closed isolation valve under the unit.
Boiler System Pressure
Weak heating or hot water from a combi boiler is a separate issue: system pressure below 1 bar on the gauge, not the mains pressure at your taps.
Typical costs
What Fixing Low Water Pressure Costs
The cost depends on the cause. A gauge test pinpoints the problem first, then the fix ranges from a valve swap to replacing corroded pipework or fitting a pump.
- Check with neighbours first to rule out an Irish Water issue for free
- A pressure gauge test pinpoints the cause before any parts are bought
- Ask for a written quote covering parts and labour before work begins
Indicative 2026 ranges including labour. Pipe replacement and pump jobs vary with access and the length of pipe involved.
- Pressure gauge test €60–100
- PRV replacement €180–320
- Pipe section replacement €200–600
- Pump installation €400–800
Indicative 2026 ranges. Always confirm with the plumber before work begins.
The fixes
Fixes That Restore Whole-House Flow
Many Irish homes have a pressure reducing valve (PRV) fitted where the mains supply enters the house, near the stopcock under the kitchen sink. Over time a PRV can restrict flow and cause low pressure. A plumber can test it with a pressure gauge and replace it if needed, which makes an immediate difference to whole-house flow.
In hard water areas, limescale narrows the internal bore of pipes and fittings over years, and older galvanised steel pipes corrode and narrow from the inside. Replacing affected sections with copper or plastic (MDPE) typically makes a dramatic difference. Where mains pressure is genuinely low, a booster pump can be fitted to lift flow across the whole house.
Browse by county
Find a Plumber in Your County
Every plumber listed is contactable directly to test your pressure and fix it, county by county across Ireland.
Leinster
12 countiesDublin and the east, where hard water and limescale narrow older pipework and sap the flow.
Munster
6 countiesCork, Limerick and the south west, from city terraces to rural homes on private supplies.
Connacht
5 countiesGalway, Mayo and the west, where long rural supply runs and older pipes affect pressure.
Common questions
Low Water Pressure: Common Questions
Why is my water pressure suddenly low?
Turn on taps in different parts of the house and compare the flow. Poor pressure at every outlet points to the incoming supply, the pressure reducing valve, or a leak in the main supply pipe. If only one tap or shower is affected, it is usually a blocked aerator, a partly closed isolation valve, or a failing tap cartridge.
How do I know if it is an Irish Water problem?
If multiple houses on your street have low pressure at the same time, the issue is with the Irish Water (Uisce Eireann) mains supply, not your property. Check the outage map at water.ie or call their customer care line. They are responsible for maintaining supply pressure up to your property boundary.
Can a pressure reducing valve cause low pressure?
Yes. Many Irish homes have a PRV fitted where the mains enters the house, near the stopcock under the kitchen sink. As it ages it can restrict flow and drop pressure across the whole house. A plumber can test it with a gauge and replace it, typically for €180 to €320 including parts and labour.
Why is my combi boiler losing pressure?
Boiler system pressure is separate from mains water pressure. If the boiler gauge reads below 1 bar, repressurise the system using the filling loop. If the pressure drops repeatedly after repressurising, there is a leak in the central heating circuit that a plumber needs to find and fix.
Still Low on Pressure? Find a Plumber
Once you have ruled out the easy causes, a plumber can test the pressure and fix whatever is restricting the flow. Browse RGI-registered plumbers across Ireland and call them directly.
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