If your Fairfax water heater is leaking or has gone cold, a few quick steps protect the house, and a plumber can usually trace the trouble to one part, a valve or sediment. A tank leaking from its body must be replaced. Call the number on this page to be connected with a local plumber in Fairfax.

Fairfax at a glance
The City of Fairfax is an independent city and the county seat, with a redeveloped Old Town core and older neighborhoods around it. Census figures put the median home at 1967, so many houses keep their water heater in a basement or utility room with older gas piping and venting. Water comes from Fairfax Water, drawn from the Potomac River and Occoquan Reservoir; Potomac plant tests show total hardness of roughly 70 to 185 mg/L, which leaves sediment in tanks over time. Gas service is Washington Gas.
Permits depend on which side of the city line you are on. Inside the city, plumbing permit applications go to the City's Code Administration in the Fire Department. Most of the Fairfax ZIP codes outside city limits are unincorporated Fairfax County, where Land Development Services issues a Household Appliance permit even for a like-for-like gas water heater replacement, with a chimney vent certification for fuel-burning appliances.
What to do right now
- If you smell gas, leave the house first. From outside, call 911 and Washington Gas at 844-WASHGAS (844-927-4427), option 1.
- If water is leaking, close the cold-water valve above the heater.
- Turn off the energy: the breaker for an electric unit, or the gas control knob to off.
- Keep water away from finished areas. Use towels and move boxes off the floor.
- Check simple causes: a tripped breaker or a pilot that went out.
- Write down the label details and anything you heard or smelled.
Symptoms and likely causes
| Symptom | Likely cause |
|---|---|
| No hot water on a gas unit | Thermocouple, igniter, flame sensor or gas control |
| No hot water on an electric unit | Element, thermostat or tripped high-limit |
| Hot water fades quickly | Sediment, failed lower element or broken dip tube |
| Soot or scorching near the burner | Poor combustion or a venting problem |
| Dripping relief valve line | Excess pressure or temperature, or a worn valve |
| Water at the base | Drain valve, fitting or failed tank |
Cost factors
- Which part failed and whether it is on hand
- Flushing a tank with heavy sediment
- Old venting, valves or gas connectors that need updating in older homes
- Access in tight basements or closets
- Evening or weekend timing
Water Heater Repair questions in Fairfax
Does water heater work here need a permit?
Is it worth fixing a water heater that is 10 or more years old?
What causes popping or rumbling inside the tank?
What should I have ready when I call about my water heater?
More plumbing services in Fairfax
Water Heater Repair nearby
Helpful guides
Sources
- City of Fairfax plumbing permit application
- Fairfax, Virginia (Wikipedia)
- Fairfax housing by year built (city-stats.com)
- Fairfax County: utility and cable providers
- Fairfax Water: Corbalis plant finished water analyses
- Fairfax County Land Development Services: household appliance permits
- Washington Gas: safety and emergency leak line
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