Troubleshooting Low Water Pressure

Low water pressure is annoying but usually has a simple cause. The key is figuring out whether it is one fixture or the whole house.

Step 1: Isolate the scope

• Only one faucet? It is a fixture-level issue (aerator or cartridge).
• Whole house? It is a supply issue.
• Hot only? Likely the water heater or its valve.

If it is one faucet

1. Unscrew the aerator (the screen at the spout tip) — wrap a rag and use pliers gently.
2. Clean or replace the aerator screen (mineral buildup is the usual cause).
3. Reinstall and test. Still low? The cartridge or supply tube may be kinked.

If it is the whole house

• Check the main shut-off valve is fully open.
• Check the pressure-reducing valve (PRV) if you have one — it may need adjusting or replacement.
• Ask neighbors — a street-side issue affects the block.
• Test pressure with a cheap gauge on an outdoor spigot (ideal: 40–60 psi).

If it is hot water only

• Check the water heater shut-off is fully open.
• Flush the heater — sediment can restrict flow (see your heater's manual).
• Inspect for a closed valve on the hot outlet.

Pressure suddenly dropped to a trickle? A burst pipe or major leak may be the cause — shut off the main water and check for water damage.