Single fixture, or every fixture?
A lone weak fixture usually hides its own fault. A house-wide drop points to the main valve, the piping or the street connection.
Quick checks
- Unscrew and rinse the faucet aerator.
- Soak the shower head in vinegar.
- Confirm the main valve is wide open.
- Check the shut-off valves under sinks.
- Ask neighbours if their pressure has changed.
Sudden drop? If pressure fell suddenly, check for leaks and the meter.
Deeper causes
- Galvanized pipe narrowed by rust
- A failing pressure-reducing valve
- A partly closed or broken main valve
- An undersized or lead service line
Keep a note of when the problem started and which taps are affected. That simple record helps a plumber separate a fixture problem from a pipe or service problem in minutes rather than hours. In older bungalows, mention any past repairs too, since a patch of new copper joined to old galvanized pipe is a common choke point.
When to call
If simple checks do not help, book low pressure repair.