What we do
- House pressure measured with a gauge at an outdoor faucet
- Working regulators reset to a gentler pressure
- Worn regulators swapped for the same size where the old one sits
- Expansion tanks at the water heater replaced when the bladder fails
- A tank added on the heater’s cold supply when one is missing
- Tank pre-charge matched to the house pressure before it goes in
Pressure and older San Gabriel plumbing
The Census Bureau’s 2020–2024 estimates put San Gabriel’s median year built at 1957. Plumbing in houses that age is a mix of original and replaced pipe, and older joints and valves are the first to complain when pressure runs high. The state plumbing code’s section 608.2 sets the line: above 80 psi static, a regulator with a strainer ahead of it must bring pressure to 80 psi or below.
Under that section, the cold piping downstream of each regulator also gets an expansion tank, which keeps heating water from pushing the pressure back up. Section 608.3 adds that any system with a check valve or backflow device that traps pressure needs a properly sized tank on the house side, though tankless heaters are exempt.
Our process
Measure
Gauge on an outdoor faucet, all fixtures off, reading noted.
Inspect
We check the regulator for leaks and adjustment, and test the expansion tank’s air valve for water.
Fix
Reset the regulator, or swap it in place; replace the tank with one pre-charged to match.
Confirm
A second gauge reading and a hot-water run with the relief valve watched.
Where our part stops
Installing a regulator where none exists on buried pipe, re-piping the main, or work at the meter goes to a plumber or the water provider. We service regulators and tanks that are already in reach.
Before the visit, text us
Photos of the regulator on the main line if you can find it, the water heater and anything mounted above it, and any gauge reading.
Regulator and tank questions
What pressure should a house have?
The plumbing code caps static pressure at 80 psi. We usually set it below that.
How can I tell the expansion tank has failed?
Tap it. A full, dull sound top to bottom, or water at the air valve, means the bladder is gone.
Where would the regulator be?
On the main line near where it enters the house. Some older houses don’t have one.
Does a tankless heater need a tank?
No. Section 608.3 exempts non-storage heaters.
Why does the relief valve drip?
Pressure from thermal expansion is a common cause. A working expansion tank absorbs it.
Can a regulator be adjusted?
Yes, with the screw on top. If it won’t hold the setting, it is worn out.
Will high pressure hurt old pipes?
It stresses valves, fill valves and supply lines, which is why the code caps it.
Is a strainer required?
Section 608.2 calls for one ahead of regulators smaller than 1½ inches.
How long is the water off?
Usually less than an hour for a tank or regulator swap.
Do you haul away the old tank?
Yes.
Related guides
- Washer hoses and laundry valves in older homesWhen to replace washer hoses, how to check old laundry shutoff valves in a San Gabriel garage or service porch, and the small habits that prevent a flood.
- The toilet shutoff valve that will not turnWhy the little valve behind an older toilet often will not close, and how we replace seized shutoffs and supply lines before they fail.
We’re a handyman in San Gabriel for small repairs like this one, with an upfront price by text.
This job sits in our plumbing fixes group. For other repairs, see the services overview, or start with the repair guide for San Gabriel’s older homes.