Where Flower Mound's water comes from
The Town of Flower Mound does not pull raw water from either of the lakes on its borders. Instead it buys finished, already treated water from two wholesale suppliers: Dallas Water Utilities, whose system relies heavily on Lewisville Lake along with East Texas reservoirs like Lake Ray Hubbard and Lake Tawakoni, and the Upper Trinity Regional Water District, the Denton County wholesaler that treats Lewisville Lake water for a long list of member cities. Flower Mound is one of Upper Trinity's biggest customers, and the town's own crews run the pump stations, elevated tanks and mains that carry that water to homes.
Two wholesalers, one practical outcome for your tank: lake water of middling hardness that drops a fine, silty sediment rather than the crusty white scale of a limestone aquifer. What changes most through the seasons is temperature. Lake water reaching a Flower Mound tap in August can be warm enough that a heater barely works, while a week of freezing wind in January drops it toward 50°F and exposes any tank that was undersized for a large household. Upper Trinity has been building Lake Ralph Hall in Fannin County to add supply over the coming years, so the blend reaching town may shift again.
Big houses and two-tank attics
Most of Flower Mound was built from the late 1980s onward, and much of it is large: brick and stone two-story homes of 3,000 to 5,000 square feet in Bridlewood, Wellington, Lakeside and the newer Canyon Falls area on the west side. Builders in these subdivisions commonly put two 40- or 50-gallon gas tanks side by side in the attic above the garage, each feeding one end of the house, or a single large tank plus a recirculation pump. When one of the pair fails, the household often does not notice for days because the other keeps the kitchen or the primary suite running.
Older parts of town near Morriss Road and the FM 1171 corridor have more modest homes, often with a single tank in the garage. Custom homes on acreage in the western part of town, toward Copper Canyon and the Cross Timbers country, sometimes have long pipe runs to a casita, pool bath or outdoor kitchen, which is where a tankless water heater or a dedicated point-of-use unit tends to show up.
Heat, hail and the 2021 freeze
North Texas attics routinely pass 130°F in July. That heat dries out the rubber in gas control valves, bakes the plastic on condensate lines and makes the drain pan under an attic tank the only thing standing between a slow leak and a soaked bedroom ceiling. Flower Mound sits squarely in the hail corridor that runs across Denton and Tarrant counties, and spring storms regularly flatten roof jacks and bend the vent caps that sit above attic heaters, which can choke a flue without anyone looking up to see it.
The February 2021 winter storm left a different mark. Attic supply lines and the copper or PEX feeding twin heaters split in homes all over town once power and gas pressure faltered, and several water heaters were drained or replaced after the thaw. Many owners added pipe insulation and attic heat tape afterward, which is worth checking on any home you are buying here.
The problems plumbers see most in Flower Mound
- One of two attic tanks quietly failing while the second hides the problem from half the house.
- Overflowing or rusted drain pans above garage ceilings and upstairs bedrooms.
- Recirculation pumps that run constantly and wear out a tank years early.
- Hail-bent flue caps on the roof above an attic heater.
- Undersized tankless units starved by a soaking tub and two showers on a January morning.
- Pilot and igniter faults on gas controls that have spent a decade in attic heat.
Water heater prices in Flower Mound
| Job | Typical Flower Mound range | Notes |
|---|---|---|
| Igniter, thermocouple or pilot assembly | $175–$325 | Attic access adds time |
| Gas control valve | $425–$700 | |
| Drain pan and pan drain line replacement | $250–$550 | Often done with a tank swap |
| Recirculation pump repair or replacement | $350–$800 | |
| 50-gallon gas tank in the attic | $2,000–$3,600 | Permit, pan and haul-away |
| Swapping the pair in a twin-tank attic | $3,800–$6,800 | Pricing per pair, not per tank |
| Tankless installation | $4,000–$7,000 | Gas line upsizing is common |
Flower Mound pricing runs toward the upper end for the Dallas-Fort Worth area. Most of the premium comes from attic work: carrying a tank up pull-down stairs, replacing a pan in a tight space between trusses, and the second technician many companies send for that lift.
Permits, inspections and Texas licensing
Replacing a water heater in Flower Mound calls for a permit through the town's Building Inspections division, and the town inspector checks the gas hookup, where the relief valve line ends, the drain pan and its outlet, venting clearances and the attic walkway and lighting the code expects for appliance access. Homes in the parts of town with their own HOA architectural rules occasionally have requirements about exterior vent locations for tankless conversions.
Flower Mound plumbers work under licenses from the TSBPE in Austin, and the gas piping on a Flower Mound heater needs a licensee with the matching gas endorsement. Before work starts in an attic, confirm the plumber's TSBPE number and that the Flower Mound permit fee is part of the written quote.
Sizing hot water for a large Flower Mound household
A five-bedroom home with a garden tub, multiple showerheads and a teenager or two can drain a single 50-gallon tank before the evening routine is half done, which is exactly why so many Flower Mound builders went with two tanks. When one fails, it is tempting to replace just that one. If both are within a few years of each other, though, replacing them together spares you another attic haul, another inspection fee and another afternoon off work.
Converting to tankless is common in remodels, but a whole-house unit sized for a big home may need a larger gas line from the Atmos Energy meter, and a pair of tankless units may be the better fit for houses that were plumbed in two zones. Your plumber should check the existing gas pipe size and the winter inlet temperature before quoting flow rates.
Electric service and efficiency options
Electric service in Flower Mound depends on the address. Much of town is on Oncor's lines, where residents pick a retail electric provider, while some areas are served by CoServ, the Denton County cooperative. Anyone weighing a heat pump tank should price it against their own CoServ or retail plan, and either utility may have offered efficiency programs at times. Atmos Energy supplies natural gas across town.
A heat pump heater in an attic will cool and dry the space around it, which is a mild bonus in summer, but it needs room for airflow and a condensate drain. Garage installations are often a simpler fit for that option.
Repair or replace in Flower Mound
On a tank that is younger than eight or nine years, most Flower Mound owners come out ahead by replacing just the failed igniter, valve or relief part. Past that point, a weeping tank seam above a living space is a strong reason to replace rather than gamble, because a failed attic heater can cost far more in drywall and flooring than the heater itself. If you are seeing water in the pan, rust on the tank jacket or a hissing from the burner area, start with our page on tanks dripping into the pan, and water heater replacement covers attic swaps.
Simple upkeep for attic heaters
Every few months, climb up and look at the pan under each tank. A dry pan with a clear drain line is what you want; any rust stain or standing water means a call. A yearly flush helps clear the silty lake sediment that settles on Flower Mound tanks, and our flushing service can handle both tanks in one visit. After any hailstorm, have someone check the vent caps on the roof.
Around Flower Mound
Lewisville runs its own treatment plant on the lake next door. Highland Village, Argyle, Bartonville and Copper Canyon each handle their own permits, and several rural areas west of town rely on special utility districts or wells. Grapevine, Coppell and Southlake to the south sit in other counties with their own inspection offices and supply arrangements.
Water heater questions from Flower Mound
Why does my Flower Mound house have two water heaters?
Large homes here were often plumbed in two zones, each with its own tank in the attic, so long pipe runs do not leave far bathrooms waiting for hot water.
If one of my two attic tanks fails, should I replace both?
If they are the same age, replacing both together often costs less overall than two separate attic jobs a year or two apart.
Who supplies Flower Mound's water?
Two wholesalers: Dallas Water Utilities and the Upper Trinity Regional Water District, mostly sourced from Lewisville Lake.
Is there water in my attic drain pan a problem?
Yes. Any standing water or rust in the pan suggests a leak at the tank or a fitting. Shut off the cold supply and have it inspected before the pan overflows.
Will the town inspect my new attic heater?
Yes. The town's Building Inspections division permits and inspects water heater replacements, including attic installs.
Can a tankless unit handle a big Flower Mound home?
It can, but whole-house units often need a larger gas line, and some homes are better served by two units matched to their two plumbing zones.
My electric is from CoServ, not Oncor. Does that change anything?
Only the rate and any incentive programs. A licensed plumber installs the heater the same way; your utility affects running cost for electric or heat pump models.