Buying or maintaining a home in Houston — whether in Katy, Cypress, The Woodlands, or Sugar Land — means dealing with heat, humidity, and plenty of plumbing demands. But there’s one issue many homeowners don’t think about: what’s actually happening inside your home’s plumbing system.
Water heaters, pipes, and even rarely used faucets can become breeding grounds for bacteria like Legionella pneumophila, the organism responsible for Legionnaires’ disease. It’s not a new problem, but it’s one that many Texans unknowingly overlook until a major issue arises.
Below is a simplified, Houston-friendly guide to understanding the risk — and the steps you can take to keep your home’s water system healthy and safe.
What Is Legionella — and Why Should Houston Homeowners Care?
According to the CDC [VERIFY], Legionella occurs naturally in freshwater sources. It becomes a problem when it multiplies in human-made water systems, including:
- Water heaters
- Showers and faucets
- Hot tubs
- Ice machines
- Decorative fountains
- Pools
- Landscape water features
The bacteria grow fastest in stagnant warm water between 68°F and 120°F. The ideal growth zone? 90°F–105°F — which is exactly the temperature range many older or improperly set water heaters operate in.
For homeowners across Houston’s suburbs — especially in areas with large two-story homes, extended plumbing lines, or oversized water heaters — this risk can be higher simply because large systems tend to have more unused, stagnant water sitting in pipes.
How Legionella Spreads in a Home
Legionnaires’ disease is a lung infection, often appearing similar to the flu. People become sick after inhaling airborne water droplets containing the bacteria. This can happen:
- In a shower
- Through steam
- From a running faucet
- When using contaminated appliances
OSHA estimates that 10,000–50,000 people are hospitalized annually with the disease [VERIFY].
While anyone can be affected, maintaining a healthy plumbing system is crucial for all Houston homeowners, especially those purchasing older properties in established suburbs such as The Woodlands, Tomball, or Spring.
Why Houston’s Water Systems May Be More Vulnerable
A surprising factor affects many Texas homeowners: water travel time.
Federal water conservation efforts beginning in the 1990s slowed the flow rate in municipal systems. As U.S. News notes, water that once traveled from the treatment plant to your home in 2 days may now take up to 2 weeks in certain regions.
Why does that matter?
- Chlorine — the municipal disinfectant — loses its potency rapidly.
- By the time water reaches far-out suburbs like Hockley, Porter, or New Caney, chlorine levels may be too low to suppress bacteria.
- Slow-moving water becomes more susceptible to contamination from corrosion, pipe breaks, or sediment.
Combined with Houston’s warm climate, these conditions create a perfect environment for microbial growth.
Water Heater Temperatures Matter — A Lot
OSHA recommends setting water heater temperatures to 140°F to kill Legionella.
But this introduces another concern: scalding.
A practical solution is installing thermostatic mixing valves, which allow:
- High temperatures inside the tank
- Lower, safe temperatures at the tap
- Reduced risk of burns
- Improved bacterial control
For Houston homeowners replacing old water heaters (common in homes over 10 years old in Katy, Cypress, or Sugar Land), this is an ideal time to upgrade to safer, more efficient systems.
Gas vs. Electric Water Heaters — Which Is Safer?
A Canadian study of 211 homes found:
- 33% of homes with electric water heaters tested positive for Legionella
- 0% of gas-powered water heaters did
Why the difference?
Electric water heaters often:
- Maintain lower temperatures
- Have heating elements on the side, leaving sediment untouched
Gas water heaters:
- Heat from the bottom, where sediment collects
- Reach higher temperatures more consistently
- Provide better protection overall
Many Houston homeowners — especially those in high-turnover suburban markets like Katy and The Woodlands — choose gas heaters for improved efficiency and longevity.
Regardless of type, annual draining and full cleaning (not just flushing) is essential.
Buying a Vacant Home in Houston? Pay Extra Attention
Vacant homes — including foreclosures and new construction sitting unoccupied — are prime environments for Legionella. Without water usage, everything inside the plumbing system becomes stagnant.
Whether you’re purchasing a home in Conroe, Spring, or Tomball, plan on a full system flush before move-in.
NSF International recommends using superheated water to sanitize plumbing systems:
How to Perform a Monthly Safety Flush:
- Turn your water heater to its highest setting.
- Run each faucet for 30 minutes.
- If your tank can’t handle all taps at once (most can’t), run 1–2 at a time for 15 minutes.
- Start with faucets closest to the water heater and move outward.
- Run your dishwasher and washing machine on their hottest settings.
- Reduce the water heater temperature back to normal when finished.
Important Notes:
- Avoid splashing.
- Only adults in good health should perform the flush.
- Children and vulnerable individuals should leave the home during the process.
Simple Ways to Protect Your Houston Home’s Plumbing System
Here are practical actions you can take:
✔ Set your water heater to 140°F (with mixing valves for safety).
✔ Drain and clean your water heater annually.
✔ Run rarely used faucets weekly.
This prevents stagnation — especially important in large homes or guest suites.
✔ Flush your plumbing after storms or water main breaks.
Houston sees plenty of infrastructure disruptions.
✔ Consider upgrading older electric water heaters.
✔ If buying a vacant home, sanitize the plumbing before occupancy.
Proper maintenance protects your home, preserves your plumbing system, and ensures cleaner, safer water for everyday use.
Have questions about a home’s plumbing, inspections, or maintenance before you buy? Reach out to Jennifer Yoingco, REALTOR®, and her team, The Houston Suburb Group. They’ll help you get ready to EXPERIENCE LIVING IN HOUSTON TEXAS!
FAQs
Q1: Can Legionella grow in modern plumbing systems?
Yes. Even newer plumbing can generate stagnant warm water, especially in large homes, unused bathrooms, or improperly set water heaters.
Q2: How often should Houston homeowners flush their plumbing system?
Once per month is recommended, especially if you live in a large home, have low-use faucets, or own a property that has been vacant.
Q3: Do tankless water heaters prevent Legionella?
They reduce the risk because they don’t store water, but they do not eliminate it completely. Proper maintenance is still required.
Q4: Is 140°F safe for water heaters?
Yes — when paired with thermostatic mixing valves. This allows bacteria-killing temperatures in the tank and safe delivery at faucets.
Download our FREEBIES here!
The Ultimate Home Buyer’s Guide
The Ultimate Home Seller’s Guide
Find us on YouTube!
#jenniferyoingcorealtor #jenniferyoingco #JenniferYoingcoTexas #houstonsuburb #houstonsuburbs #houstonsuburbgroup #texasrelocationexperts #HoustonRelocationExpert #HoustonRelocationSpecialist #NurseRelocationExpert #NurseRelocationSpecialist #newhomeconstruction #thehighlands #ravennahomes #ravennahomesforsale #ravennahomesrealtor #ravennahomesrealestateagent #springtexas #tomballtexas #livinginhoustontexas #livinginhouston #thewoodlandstexas #conroetexas #montgomerytexas #cypresstexas #newcaneytexas #portertexas #katytexas #pearlandtexas #richmondtexas #fulsheartexas #sugarlandtexas #houstontexas #magnoliatexas #hockleytexas #pinehursttexas #jerseyvillagetexas #humbletexas
