//Quick answer
- One fixture: aerator, cartridge, angle stop. Small repair.
- Whole house: regulator, main shutoff, or the piping itself.
- Pressure that drops when two fixtures run is a piping symptom.
01Definition
What causes low pressure at one fixture?
Scale or debris in the aerator, a cartridge clogged with sediment, an angle stop under the sink that was never fully reopened, or a shower valve with scale in the mixing chamber. Each one is local, and each one is a small repair.
What causes low pressure in the whole house?
A failed or misadjusted pressure regulator on the main line, a main shutoff or meter valve not fully open, a leak large enough to steal pressure, or supply piping, especially galvanized steel, that has rusted inside until the open diameter is a fraction of the pipe. Pressure that collapses when a second fixture runs is the classic sign of the last one.
02When it applies
What can you check yourself?
Unscrew and clean the aerator. Confirm the angle stops under the fixture are fully open. Compare hot and cold: low hot pressure only points at the water heater or its valve. Put a gauge on a hose bib if you have one; the reading tells the technician a lot.
When is it a repipe conversation?
When the house has galvanized pipe, rusty water, and pressure that falls off with two fixtures running. That is the piping at the end of its life, and the repipe guide walks through the signs and the $18,000 to $30,000 range. A regulator or a valve is a far smaller fix, and the technician rules those out first.
03What goes wrong
What does a failing regulator do besides low pressure?
It can also fail high: banging pipes, spitting faucets, a water heater relief valve that keeps discharging. Either way the regulator is a high-value small repair, and it is part of Done-Rite's outdoor plumbing repair service.
04Proof
- April Morris, Google, November 13, 2019: "We called Done-Right to install pressure regulator for one of our water meters. Logan was great. Five stars!"
- No trip charge, a 1-hour response time, and 24/7 emergency service.
- Six plumbers averaging more than 9 years in the trade each, plus a General Manager with 25+ years.
- 1 year minimum warranty on labor. Manufacturer warranty handling varies by manufacturer.
05Action
Find out which one it is
Fixture, regulator and valve work is quoted on site; call for pricing. No trip charge. If it is the piping, you hear the repipe range plainly: $18,000 to $30,000 by bathroom count.
//Keep going
Learn
//Terms used in this guide
Where this applies
Done-Rite runs these calls across Orange County from its shop in Anaheim, CA, with no trip charge in any city it serves.
Common questions
Usually a clogged cartridge or aerator, a partially closed angle stop, or scale in the mixing valve. Whole-house low pressure is more often the pressure regulator or the supply line.
Not by itself. A regulator or a valve is checked first. Galvanized pipe, rusty water and pressure that collapses with two fixtures running together point at the piping.
If the neighbors lost pressure at the same time, it is the supply. If it is only your house, or it comes with a higher bill, a damp spot or pressure that swings, it is inside the property and needs a look.
