In Herndon, a plumbing inspection means a plumber checks the supply and drain piping, fixtures, shutoffs, water heater, gas connections and any backflow device, and can film the sewer line. Rules depend on whether the address is inside the Town of Herndon or in the surrounding county area. Call the number on this page to be connected with a local plumber in Herndon.

Herndon conditions
Herndon is an incorporated town with a historic downtown, the W&OD Trail and Silver Line access, and the median home was built around 1983. Many houses are at the age where original water heaters, shutoffs and pressure regulators need replacing.
Inside town limits, the Town of Herndon runs water and sewer. It buys finished water from Fairfax Water, mainly from the Corbalis plant on the Potomac, where hardness averages about 7.5 grains per gallon, so scale is a reasonable thing to check. The Town keeps a service line inventory and reports no lead lines found. Herndon-addressed homes outside the town, such as some south of the Dulles Toll Road, are under Fairfax County rules and usually Fairfax Water.
Gas is split too. Columbia Gas of Virginia serves the Town; some outside addresses are on Washington Gas. The utility named on the gas bill is the one that applies. During the visit the plumber can look over appliance connectors, shutoff valves at each gas appliance and the water heater's venting, which is where most gas-related findings show up in a house of this age.
Common findings and what usually happens
| Finding | Repair | Replace |
|---|---|---|
| Irrigation backflow device that's overdue | Test, and rebuild if it fails | Damaged or obsolete assembly |
| Water heater | Relief valve, flush or anode | Leaking or badly corroded tank |
| Main shutoff | Repacking | Valve that won't close |
| Main drain | Clearing a clog | Camera shows broken pipe |
Signs it's time
- A purchase with an inspection contingency
- An irrigation system with no recent test report
- Gurgling fixtures or recurring slow drains
- A water heater past its expected life
Timing and permits
The Town requires backflow devices in town, including irrigation systems, to be tested every year by a certified tester, with results sent to Town Building Inspections; spring, before the sprinklers go on, is a sensible time. Have outdoor spigots looked at before the first freezing nights. Inside the town, plumbing and gas permits come from Town Building Inspections; outside it, from Fairfax County Land Development Services. If you smell gas, leave first, call 911, then Columbia Gas at 1-800-544-5606 or Washington Gas at 844-WASHGAS (844-927-4427), option 1, whichever is on the bill.
Plumbing Inspection questions in Herndon
My mailing address uses the town's name, but I'm outside its limits. Whose rules apply?
Does the inspection include gas piping, and what if I smell gas?
Will the plumber check the backflow preventer on the irrigation system?
How can I find out what my water service line is made of?
More plumbing services in Herndon
Plumbing Inspection nearby
Helpful guides
Sources
- Town of Herndon: water and sewer
- Town of Herndon water quality report
- Town of Herndon Building Inspections: how to apply for a permit
- Town of Herndon Building Inspections: special programs
- Fairfax Water: Corbalis plant finished-water analysis
- Housing by year built: Herndon
- Columbia Gas of Virginia: safety
- Washington Gas: safety
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