Laundromat and Commercial Laundry Plumbing

If your store runs commercial washers, the plumbing code expects a lint interceptor between the machines and the sewer. The 2024 International Plumbing Code (Section 1003.6) says clothes washers discharge through an interceptor with a wire basket or similar device, removable for cleaning, that stops solids 1/2 inch or larger, plus string, rags and buttons. Only washers in a dwelling unit, or a single household-style washer outside one, get a pass. Phoenix accepts either the IPC or the UPC, so check which code your permit is under.

Why it matters: lint doesn't dissolve. It settles in the drain trench and the building sewer, binds with detergent and grit, and narrows the pipe until a Saturday rush backs water up through the floor drains. A full basket does the same thing, just closer to the machines.

Here's the routine that works:

1. 1Pull and empty the baskets on a set schedule, more often on your busiest days.
2. 2Pump the interceptor before sludge and lint fill the chamber, not after the drains slow.
3. 3Log every cleaning, with the date and who did it.
4. 4Jet the line downstream on a schedule, and whenever the same drains keep slowing. See hydro jetting vs snaking.

City sewer codes name laundries outright. Phoenix City Code 28-12 says interceptors must be installed and operated by laundries, along with restaurants, service stations and car washes, when the Water Services Director decides they're needed for solids or other harmful ingredients. Mesa City Code 8-4-22 and Scottsdale City Code 49-95 read almost the same way.

Maintenance is spelled out too. Phoenix Code 28-15 requires periodic removal of all accumulated lint, sludge and solids, a thorough cleaning of the interior, and repairs to internal parts, with records kept at the site for at least three years. Mesa and Scottsdale also set a three-year minimum for records at the facility. Our free printable maintenance log works for a lint interceptor as well as a grease trap.

In Phoenix the city also approves the interceptor itself. The city's plumbing code amendment gives the authority having jurisdiction the say over size, type and location, so plan review happens before one goes in. See Phoenix City Code 28-12.

On septic? Maricopa County requires hair and lint traps on drains connected to an onsite wastewater system at commercial laundry facilities.

Hot water is usually a laundromat's biggest plumbing load. A row of washers calling for hot fill at once on a Sunday morning will empty a heater sized for the average. The signs show up as warm fills, customer complaints and burners or elements that never rest.

Size for the peak, not the day. Count the washers, the hot water each fill uses and how many run together, then look at storage, recovery and whether two smaller heaters beat one big one for redundancy. Phoenix's hard water adds scale, so flushing on a schedule and a softener on the hot supply often pay off in heater life. See water heater recovery time, types of commercial water heaters and how hard water damages plumbing.

Replacing a heater takes a permit in Phoenix. The city's exemption for an in-kind water heater swap applies only to one- and two-family dwellings.

Phoenix City Code 37-144 lists laundry and dye works among the facilities that need an air gap or a reduced pressure (RP) assembly, and the city decides case by case for anything not on the list. Every assembly is tested at least once a year by a certified tester, the results go to the city, and the customer keeps the records three years. If your store shares a meter with other tenants in a strip center, Phoenix calls for an RP assembly there too. Here's what commercial backflow testing involves.

A store full of washers sends a lot of water to one sewer line, fast. Floor drains that gurgle or back up when several machines drain together usually point to a partial blockage downstream, often lint and scale. A sewer camera inspection shows whether it's buildup, a sag or a broken joint before anyone digs. See floor drain backing up.

We service lint interceptors, clear and jet drain lines, install and replace water heaters, and camera, repair and replace sewer lines. We also replace backflow assemblies and run gas lines for dryers and heaters. We're available 24/7, and you get an upfront price before work starts, with free estimates.