Bexar County · San Antonio–New Braunfels metro
Plumbing help in San Antonio, TX
Very Hard WaterFreeze Risk
San Antonio's defining plumbing fact is its water: it comes largely from limestone aquifers and is very hard. Scale buildup drives many local calls, from water heaters that fail early to faucets and tankless units that need regular descaling.
- Median home built
- 1986
- Built before 1980
- 40%
- Owner-occupied
- 52%
- Water hardness
- Very hard
- ≈ 17.5 grains/gal
- Winter
- Occasional hard freezes
- Plumbing code
- IPC
The plumbing calls that come up most in San Antonio
- Water Heater Repair
Water this hard deposits sediment in tank heaters quickly, causing rumbling, lost capacity and burned-out elements.
- Water Softener Installation
At 15 to 20 grains per gallon, many households soften to protect water heaters, fixtures and appliances.
- Tankless Water Heaters
Tankless heat exchangers scale up fast in hard water, so descaling on schedule matters more here than in soft-water cities.
San Antonio's very hard water and your plumbing
San Antonio Water System reports typical hardness of 15 to 20 grains per gallon, from calcium carbonate in water drawn from the Edwards and Trinity aquifers. [1]
Emergency plumbing in San Antonio
Call (833) 878-1592Shut off your main water supply if it's safe to do so. The emergencies below are listed most likely first for San Antonio homes, based on local conditions.
Plumbing code and permits in San Antonio
San Antonio's plumbing code is based on the 2024 International Plumbing Code with local amendments, effective May 1, 2025, and is administered by the Development Services Department. [2]
When San Antonio gets a hard freeze
Occasional hard freezes · median home built 1986
Polybutylene-era homes in San Antonio
The median home in San Antonio was built in 1986, and 40% of homes predate 1980. Homes from that era were typically built with copper or CPVC supply, plastic drains, and in some homes gray polybutylene supply pipe.
- Galvanized steel supply (1900–1960)
- Copper supply (1950–2000)
- Polybutylene (some homes) (1978–1996)
- PEX / CPVC (1995–today)
Heavy rain and storms
Plumbing services for San Antonio homes
San Antonio plumbing questions
How hard is San Antonio water?
Very hard. SAWS reports typical hardness of 15 to 20 grains per gallon, well above the roughly 10.5 gpg where water is classed as very hard.
How often should I flush my water heater in San Antonio?
With water this hard, flushing a tank heater at least once a year is a sensible minimum, and tankless units should be descaled on the manufacturer's schedule or sooner.
Sources (3)
- U.S. Census Bureau, ACS 2024 1-year (B25035) · checked 2026-10-01
- San Antonio Water System, Water Quality FAQs · checked 2026-10-01
- City of San Antonio, Chapter 10 Building-Related Codes (effective May 1, 2025) · checked 2026-10-01