San Diego DMA · reduced pressure zone
What an RPZ valve is
An RPZ valve is a reduced pressure zone assembly — the high-protection backflow preventer on many commercial, irrigation, and fire lines. It has two shutoffs and a relief valve in the middle that can spit when something is wrong. It also fails tests more often than a simple double-check. This page names the device. It does not test it.
How to recognize it
Brass assembly, relief port in the middle, usually above ground more often than a double-check. If the tag says RP or RPZ, write that. RPZ testing is the request when the notice names that device.
If the relief valve is discharging steadily, that is a fail in progress. Put “relief dumping” on the request. It is not always a flood emergency, but it is not a passing device.
Why RPZs are their own job
The test has more steps and more ways to fail. Rebuild kits are specific. Some testers will test but not rebuild. Write if you want repair on the same visit if it fails. We cannot promise a same-visit rebuild.
Coastal assemblies in Oceanside and other marine-air sites seize and fail more often than the same valve inland. That is a maintenance fact, not a scare line.
Fire-line and irrigation RPZs
If the assembly is on a fire service, say so. Access, shutdown, and who has to be notified are different from an irrigation cage. This site does not call the fire department and does not take a fire line out of service from a form.
Irrigation RPZs hide in green cages and vaults. Write whether the landscaper has the key. Do not put the combo in the form.
What we will not claim
No tester card, no district contract, and no guarantee of a pass. A certified local tester may contact you if they accept the lead. You can ask to see their current card before they open the device.
Related service requests
These are narrower request pages on this site, not a list of partner shops. A licensed local provider may contact you if they accept a lead.
Local statistics
San Diego backflow testing statistics, 2026 — public-record figures, not a bid from San Diego Backflow Testing.
Questions
Is an RPZ the same as a double-check?
No. An RPZ is the higher-protection assembly with a relief valve in the middle. A double-check is a different device and a different test. Use the tag if you can read it.
The relief valve is dripping. Is that normal?
A brief spit can happen. Steady discharge is a fail in progress. Request a test or a failed-test repair and write that it is dumping.
Can you rebuild it on the same visit as the test?
Sometimes, if the tester also repairs and has the kit. Ask the person who calls. This website cannot promise a same-visit rebuild.
Does every property need an RPZ?
No. Hazard and the water agency decide the device type. We will not assign a hazard class from a form. Follow the notice and the tag on the valve.
Related pages
These are more request pages on this site, not a list of partner shops. A licensed local provider may contact you if they accept a lead.
Request backflow testing in San Diego
Call if you want to talk now, or send the form. Either way this is a request, not a booked job.
Call (619) 604-7252