If you own or manage a restaurant, medical office, apartment building or light industrial space in Wheeling or Des Plaines, you have likely received a letter from the village or your water supplier reminding you that your backflow prevention assembly is due for its annual test. Miss the deadline and you can face fines or even water service interruption. Get the test done by someone unfamiliar with your system and you may end up with a failed device, an unplanned shutdown and a rushed repair bill.
This guide explains why backflow testing is required in Illinois, which devices need it, what a test involves, how much testing and repairs cost and how to keep your building compliant with minimal disruption.
What Is Backflow and Why Does It Matter?
Backflow happens when water flows the wrong way, from a building’s plumbing back into the public water supply. It can be caused by back-pressure (a boiler or pump pushing water backward) or back-siphonage (a sudden pressure drop on the main, such as a water main break or firefighting). Without protection, chemicals from a boiler, soap from a car wash, fertilizer from an irrigation system or contaminants from medical equipment can be drawn into drinking water.
Illinois requires cross-connection control under the Illinois Plumbing Code and Illinois EPA rules, and local water suppliers like those serving Wheeling and Des Plaines enforce annual testing of testable devices.
Which Buildings Need Testable Backflow Devices?
- Restaurants and commercial kitchens (dish machines, soda systems, chemical dispensers)
- Buildings with fire sprinkler systems
- Boilers and hydronic heating systems with chemical treatment
- Irrigation systems
- Medical and dental offices
- Car washes, laundromats and salons
- Manufacturing and process water
- Multi-family buildings with a commercial-style service
Types of Backflow Devices
| Device | Protection Level | Typical Application |
|---|---|---|
| Reduced Pressure Zone (RPZ) | High hazard | Boilers with chemicals, medical, process water, high-hazard irrigation |
| Double Check Valve Assembly (DCVA) | Low-to-moderate hazard | Fire sprinklers (non-chemical), some irrigation |
| Pressure Vacuum Breaker (PVB) | Back-siphonage only | Irrigation systems |
| Dual check / atmospheric vacuum breaker | Low hazard, often non-testable | Hose bibs, some fixtures |
RPZs, DCVAs and PVBs are testable devices and generally require an annual test by a state-licensed Cross-Connection Control Device Inspector (CCCDI).
What Happens During a Backflow Test
- The tester coordinates a short water shutdown with the building (typically 15–45 minutes per device).
- Test gauges are connected to the device’s test cocks.
- Check valves and relief valves are tested for proper opening and closing pressures.
- Results are recorded and submitted to the water supplier, often through an online compliance portal.
- If the device fails, repair options are quoted, and the device is retested after repair.
For restaurants we schedule early morning or between services. For offices, before opening. For multi-family, we coordinate tenant notices.
Costs: Testing, Repair and Replacement
| Service | Typical Cost Range |
|---|---|
| Annual test, first device | $95–$175 |
| Each additional device, same visit | $60–$110 |
| Repair kit (rubber parts, springs) installed | $200–$500 |
| Replace 3/4″–1″ RPZ | $700–$1,600 |
| Replace 2″ RPZ | $1,800–$3,500 |
| Fire line DCVA (4″–6″) repair/replace | $2,500–$9,000+ |
Pricing depends on device size, access, drainage for RPZ discharge and whether the fire department or sprinkler contractor needs to be involved.
Why Devices Fail
Debris
Sediment from water main work can lodge in check valves and keep them from sealing.
Worn rubber
Seats, discs and diaphragms harden over time. Kits are designed to restore the device to like-new function.
Freezing
Irrigation PVBs and outdoor RPZs crack if not properly winterized. A frozen RPZ body usually means replacement.
Improper installation
RPZs installed in pits, too high to service, or without a drain for relief discharge cause ongoing problems. RPZs periodically discharge water; without a drain, that can flood a mechanical room.
Compliance Tips for Property Managers
- Keep a device inventory with location, size, make, serial number and test date.
- Bundle testing of all devices on one visit to reduce cost and shutdowns.
- Schedule irrigation tests at spring startup so devices are verified when they go back into service.
- Plan for repairs. A device older than 10–15 years often costs more to rebuild repeatedly than to replace.
- Coordinate with your HVAC contractor. Boiler fill lines with chemical feeders often need an RPZ; when boilers are replaced, the backflow device should be reviewed.
Because MMDS handles both commercial HVAC and plumbing, we can review your boiler fill, cooling tower makeup and humidifier water lines at the same time we test your domestic and fire devices.
What If I Miss the Deadline?
Water suppliers typically send a reminder, then a final notice. Continued non-compliance can lead to fines and, in some jurisdictions, water service termination until the device is tested. If you have received a final notice, call us and we will prioritize scheduling.
Residential Backflow
Homeowners with irrigation systems in Wheeling and Des Plaines often have a PVB or RPZ that also needs periodic testing. We combine testing with spring startup and fall plumbing service.
Installing a New Backflow Device the Right Way
When a device fails beyond repair or a new tenant brings in equipment that creates a cross-connection, installation details matter as much as the device itself. An RPZ should be installed above grade, at a height a tester can reach, with clearance on all sides. Because RPZs discharge water through their relief port, they need an air gap and a drain sized to handle full discharge. Installing one in a ceiling above finished space without a drain pan and drain is a recipe for water damage. DCVAs on fire lines must be coordinated with the sprinkler contractor and the fire department, since the work may impair the fire protection system temporarily. Many villages require a plumbing permit and a submittal to the water supplier for new devices.
We also look at the bigger picture. If your building has several small devices scattered on individual equipment, a properly sized premise isolation device at the service entrance may simplify compliance, though local rules often still require point-of-use protection on high-hazard equipment. For restaurants in Wheeling and Des Plaines changing ownership, a backflow survey before opening avoids surprises at the health inspection.
Financing Available
Unplanned repairs rarely arrive at a convenient time. MMDS offers financing through Sunbit and PowerPay, so you can spread the cost of a repair or upgrade into manageable monthly payments. Approval is quick, and most customers get a decision in minutes. Ask your technician about options when you get your quote.
Frequently Asked Questions
How often do backflow devices need testing?
Annually for most testable devices, plus after installation, relocation or repair.
Who can test backflow devices in Illinois?
A licensed plumber holding an Illinois Cross-Connection Control Device Inspector certification.
Will testing shut off our water?
Briefly. Most tests take under 30 minutes per device. We schedule around your operating hours.
Why does my RPZ drip or spit water?
Occasional discharge can be normal during pressure fluctuations; constant discharge means a failed check or relief valve that needs repair.
Does the fire sprinkler backflow need testing too?
Yes. Fire line devices are commonly tested annually, often coordinated with the fire sprinkler inspection.
Schedule Service with MMDS
Mechanical Management & Design Solutions has served Skokie, Wheeling, Arlington Heights, Des Plaines, Mount Prospect, Palatine, Schaumburg, Glenview, Northbrook, Evanston and the rest of the north and northwest suburbs for years. We handle HVAC, electrical and plumbing under one roof, so a problem that crosses trades gets solved in one visit instead of three. If you need help with backflow testing and repair, call (847) 221-6280 or request service online. We give clear, written quotes before any work starts.