Low water pressure usually traces back to one of a handful of causes: a partially closed shutoff valve, a clogged aerator, corroded or undersized pipes, a failing pressure regulator, or a leak somewhere in the system. Most of those you can check yourself in under 30 minutes. A few of them — particularly widespread pipe corrosion or a hidden leak — will need a professional. Work through the list below in order, from the easiest fixes to the ones that point toward something more serious.
Start With the Obvious Stuff
Before you call anyone, spend five minutes ruling out the simple culprits.
Check every shutoff valve in the path. There are two that matter most: the main shutoff where the water line enters the house (usually near the front foundation or in a utility closet) and the meter shutoff at the curb box. Both should be fully open — a gate valve turned all the way counterclockwise, or a ball valve with the handle parallel to the pipe. A valve that’s even a quarter-turn closed can cut pressure noticeably.
Test whether it’s one fixture or the whole house. Turn on a tap in the kitchen, one in a bathroom, and an outdoor hose bib. If pressure is low everywhere, the problem is upstream — the main line, the pressure regulator, or the meter. If it’s only one faucet, start at the aerator: unscrew the small screen at the tip of the spout, rinse out the mineral buildup, and reattach it. Bakersfield’s water supply runs hard — calcium and magnesium deposits clog aerators and showerheads faster here than in softer-water cities, so this fix works more often than people expect.
Ask your neighbors. If two or three houses on the block are all running low at the same time, the water utility is likely doing maintenance or dealing with a main break. That’s not your problem to solve — just wait it out and call the city’s water line if it persists past a few hours.
The Pressure Regulator — the Part Most Homeowners Forget
Most homes built after the mid-1980s have a pressure-reducing valve (PRV) installed on the main line, usually within a few feet of where the water enters the house. It looks like a bell-shaped brass fitting. Its job is to knock street pressure (which can run 80–150 psi in parts of Bakersfield) down to a safe household range of 45–65 psi.
When a PRV starts to fail — they typically last 10–15 years — it can do one of two things: stick open and let pressure run too high, or stick partially closed and starve the house. A failing regulator almost always produces whole-house low pressure rather than a single-fixture problem.
You can test line pressure yourself with an inexpensive gauge that threads onto a hose bib (available at any hardware store for under $15). If the reading is below 40 psi and all your valves are open, the PRV is the first thing a plumber will look at. Replacing one is a straightforward repair — but it does require shutting off the main and working on a pressurized line, so most homeowners leave it to a professional.
Corroded or Scaled-Up Pipes
If your house was built before the mid-1980s, there’s a reasonable chance it still has galvanized steel supply lines. Galvanized pipe corrodes from the inside out. Over decades, rust and mineral scale build up on the interior walls, narrowing the passage until water barely trickles through — even though the pipe looks intact from the outside.
The giveaway signs:
- Pressure that has gotten gradually worse over years, not suddenly
- Slightly brownish or rusty water, especially after the system sits idle overnight
- Low pressure that’s worse at fixtures farthest from the main (the end of the run gets the least flow)
- Visible orange staining around older faucets or in the toilet tank
There’s no cleaning fix for heavily corroded galvanized pipe. The scale is part of the pipe wall at that point. The long-term solution is a whole-house repipe — replacing the old steel lines with copper or PEX. It’s a multi-day project, but it’s often transformative: homeowners who’ve lived with a slow trickle for years describe the difference as going from a garden hose to a fire hose. If you’re in an older Bakersfield home and have been losing pressure steadily for years, it’s worth having a plumber assess the pipe condition before you spend money on anything else.
What If There’s a Leak?
A leak in the supply system — whether it’s a pinhole in a copper line, a cracked fitting, or a slab leak under the foundation — bleeds pressure away before the water ever reaches your faucets. The tricky part is that supply-side leaks don’t always announce themselves with a wet floor. A slab leak can run for weeks under a concrete foundation before it surfaces as a warm spot on the tile, a soft patch in the carpet, or a water bill that suddenly doubles.
Here’s a quick DIY leak check:
- Turn off every water-using appliance in the house — dishwasher, ice maker, irrigation, everything.
- Find your water meter (the curb box near the street) and note the reading, or look for the small triangle or dial that spins when water is moving.
- Wait 15–20 minutes without using any water.
- Check the meter again. If it moved, water is flowing somewhere it shouldn’t be.
If the meter test points to a leak but you can’t find it visually, that’s when professional leak detection becomes valuable. Electronic listening equipment and thermal imaging can locate a leak inside a wall or under a slab without tearing out drywall or jackhammering concrete — narrowing the repair to a targeted area rather than exploratory demolition.
When to Stop Troubleshooting and Call a Plumber
Handle it yourself if: the problem is a single clogged aerator or showerhead, a shutoff valve that wasn’t fully open, or a neighborhood-wide outage the utility confirms.
Call a professional if:
- Pressure is low throughout the whole house and all valves are open
- The meter test shows water moving when everything is off
- You have galvanized pipe and pressure has been declining for years
- You notice warm floor spots, unexplained wet patches, or a spiking water bill alongside the pressure drop
- You’ve replaced the aerators and the pressure is still weak at multiple fixtures
Those last scenarios — hidden leaks and corroded pipe — aren’t DIY territory. Misdiagnosing a slab leak and ignoring it long enough can mean significant structural damage and mold remediation on top of the plumbing repair.
If you’ve worked through the checklist above and the pressure is still poor, or if the meter test showed movement with everything off, it’s time to get a plumber’s eyes on the system. All Pro Plumbing Heating and Air serves Bakersfield and the surrounding valley — call (661) 863-9242 to schedule a diagnostic visit and find out exactly what’s stealing your pressure.