Commercial plumbing covers restaurants, offices, stores, apartment buildings and industrial sites, including grease traps, commercial water heaters, high-volume drains and code-required backflow prevention. Backflow preventers stop contaminated water from flowing back into the public water supply, and most water utilities require a certified tester to check them, often every year.
Call for Same Day Service (833) 763-0420
Commercial Plumbing Problems That Need Attention
In a business, plumbing problems cost more than repairs: a backed-up restroom or kitchen drain can close a dining room or fail an inspection. These are the problems commercial plumbers see most. For specific services, see backflow testing and grease trap service.
- Drains backing up in kitchens or restrooms
- Grease trap odors or overflows
- Low water pressure at fixtures
- A water heater that can't keep up with demand
- A backflow testing notice from your water utility
- A failed health or building inspection
When a Commercial Plumbing Problem Is an Emergency
For a business, the emergency threshold is lower than at home. Sewage near food prep, an overflowing grease trap, or no water to required restrooms and handwashing sinks all need immediate attention.
- Sewage is backing up in a kitchen, restroom or food prep area.
- A grease trap is overflowing.
- There's no water to the building or to required restrooms and handwashing sinks.
- A water heater failure leaves a restaurant without hot water for dishwashing.
What to Do Right Away at a Business
- Shut off water to the affected fixtures or area.
- Put affected restrooms or sinks out of service.
- If sewage backs up into a food prep area, stop food prep and follow your local health department's rules.
- Call a commercial plumber. Many offer after-hours service to limit downtime.
How Commercial Plumbing Service Works
Commercial work is usually scheduled around business hours. Backflow testing follows a set routine: a certified tester checks the assembly with a calibrated gauge kit, repairs it if it fails, and submits the results to the water utility.
- Schedule the work around business hours when possible.
- Diagnose the problem with commercial-grade cameras and equipment.
- Repair or replace the failed equipment to commercial code.
- For backflow, a certified tester tests the assembly and submits the results to the water utility.
- Provide documentation for inspections and maintenance records.
Backflow Prevention Assemblies
- Reduced pressure zone (RPZ) assembly
- Gives the highest level of protection, for high-hazard connections.
- Double check valve assembly
- Used for lower-hazard connections, such as many fire sprinkler systems.
- Pressure vacuum breaker
- Common on irrigation systems.
What Affects the Cost of Commercial Plumbing Service
Commercial pricing depends heavily on timing, building size and the equipment involved. After-hours work to avoid closing usually costs more, but it lets the business stay open while the work is done.
- Timing. After-hours work to avoid closing the business usually costs more.
- Building size, fixture count and how hard the pipes are to reach.
- Commercial-grade equipment such as large water heaters, grease interceptors and backflow assemblies.
- Repairs found during a backflow test, such as springs, seats or relief valves.
- Permits and documentation required by the city, utility or health department.
Records Inspectors Commonly Ask For
Many plumbing-related inspection problems come down to missing paperwork rather than failed equipment. Keep these together where a manager can find them:
- Backflow test results and the date of the next required test.
- Grease trap or interceptor service tickets, with dates and how full it was.
- Water heater service records, if the business relies on hot water for dishwashing or handwashing.
- Plumbing permits and final inspection sign-offs for recent work.
Commercial Permit Rules That Vary by City
Commercial plumbing rules depend on where the building is. In Memphis, plumbing work must be done by a licensed contractor registered with the Memphis and Shelby County Office of Construction Code Enforcement, and only a licensed plumbing company can pull the permit. In Seattle, plumbing permits for commercial buildings come from Public Health - Seattle & King County, not the city's building department.
What to Have Ready for a Commercial Service Call
Having the utility notice or inspection report on hand tells the plumber exactly what needs to be done and by when.
- The location of the main shutoff, backflow assembly and grease trap.
- Any utility notice or inspection report that prompted the call.
- The hours when work can be done without disrupting customers.
After Commercial Plumbing Work
Keep every test result and service ticket. Inspectors and water utilities often ask for them.
- Keep test results and service records for inspections.
- Schedule the next backflow test and grease trap service before they're due.
- Watch high-use drains for slowing, which signals buildup returning.
Preventive Maintenance for Commercial Plumbing
- Jet kitchen grease lines on a regular schedule.
- Pump grease traps as often as local rules require.
- Test backflow assemblies when your utility requires it, often every year.
- Set up a preventive maintenance plan for high-use restrooms and kitchens.
Commercial Plumbing Questions Business Owners Ask
How often is backflow testing required?
Many water utilities require annual testing. Your utility's notice states the deadline and how to submit results.
Who can test a backflow preventer?
A certified backflow tester. Many plumbing companies have certified testers on staff.
Do commercial plumbers work after hours?
Many do, so restaurants and businesses can avoid closing during repairs.
Reviewed by Ron Olsen, Master Plumber, certified in Washington