Bulwark Plumbing installs, repairs and descales tankless water heaters across Grapevine and the DFW metroplex. We size the unit to your winter water temperature, check the gas line and venting before we price it, and tell you plainly when a tank is the better fit.
A tankless water heater gives continuous hot water and frees up floor space, but it costs more to install than a tank, often needs a bigger gas line and new venting, and needs descaling about once a year in North Texas hard water. It is worth it for some houses and not for others.
Bulwark Plumbing sizes a tankless water heater by flow rate at your winter temperature rise, checks the gas supply and venting first, and gives you a written flat price for both tank and tankless before any work starts.
A tankless water heater is worth it when the household wants hot water that does not run out, needs the space a tank takes up, or plans to stay long enough for a longer lived unit to matter. It is a harder sell when the existing tank installation is simple and cheap to repeat, or when the gas line, venting and electrical work a conversion needs would be extensive.
North Texas adds two local factors. First, the water is hard, so a tankless water heater here needs regular descaling or it loses output and starts throwing error codes. Second, incoming water in January is much colder than in August, so the unit has to be sized for winter or it will fall short exactly when you notice it most. Neither is a reason to avoid tankless. Both are reasons to have it sized and maintained properly.
Neither is better for every house. This is how we explain the trade-off on an estimate, without dollar figures, because the numbers depend on the house.
| Tank | Tankless | |
|---|---|---|
| Hot water supply | Limited to what is stored, then recovers | Continuous, up to the unit’s flow rating |
| Space | Floor space in a garage, closet or attic | Wall mounted, far smaller |
| Installation | Usually simpler, often like for like | Often needs a larger gas line, new venting and an outlet |
| Up front cost | Lower | Higher |
| Maintenance in hard water | Flush the tank, check the anode rod | Descale the heat exchanger, clean the inlet filter |
| Main failure | The tank rusts through and must be replaced | Scale, igniter or sensor faults, usually repairable |
| Standby heating | Keeps a full tank hot around the clock | Heats only when a tap is open |
If you are replacing a failed tank and a like for like swap suits the house, our water heater replacement page covers that job. If you want a tankless water heater instead, the rest of this page covers what it takes.
Note the error code on the display and call. A licensed plumber will tell you whether it is scale, gas supply or a part, and whether it can wait for morning.
A tankless water heater is sized by flow rate at a given temperature rise, not by gallons. The question is how many fixtures will run at once and how much the unit has to raise the water temperature to get there.
An undersized tankless water heater does not run out of hot water the way a tank does. It runs lukewarm when too many fixtures open at once. That is why we size for the coldest month rather than an average.
A gas tankless water heater burns far more gas at full fire than a tank heater does. The line that fed the old tank was sized for the tank, so it is often too small for the new unit. Gas line size depends on the total demand of every gas appliance on the line and the length of the run, not just the tankless unit.
An undersized line starves the unit. It short cycles, shuts down with an error, or delivers lukewarm water, usually when another gas appliance is also running. Fixing that after the fact means opening up the gas line anyway, so we check it before pricing the tankless water heater. Where a larger line is needed, our gas line crew runs it, pressure tests it, and the work is permitted and inspected where the city requires it.
A gas tankless water heater needs venting made for that unit, which is usually different from the vent an old tank used. Many tankless units use sealed venting and draw combustion air from outside. The vent material, length, number of bends and termination point all follow the manufacturer’s instructions and local code.
That means a tankless water heater conversion is rarely just a matter of reusing the old flue. The vent route can decide where the unit is mounted, since an exterior wall close to the gas and water lines keeps it short. Outdoor rated units avoid interior venting altogether, but they need protection from freezing, which North Texas learned about in February 2021.
An electric tankless water heater draws a very large electrical load at full output. Whole house electric units often need more capacity than an older electrical panel has, and some homes cannot support one without electrical service work. Smaller electric units are useful at a single fixture far from the main heater.
We check the electrical side before recommending an electric tankless water heater, and we tell you if gas or a tank is the more practical answer for the house.
Converting from a tank to a tankless water heater is more than swapping one appliance for another. A typical conversion covers:
We price each of those items so you can see what the conversion adds compared with a new tank. Where both are legitimate, you get a written flat price for each.
Hard water is the biggest maintenance issue for a tankless water heater in DFW. As water passes through the heat exchanger and heats up, minerals drop out as scale on the inside of its narrow passages. Scale insulates the exchanger, so the unit works harder for the same output, overheats internally, and eventually trips a fault.
The signs are lower hot water output, temperature swings, and scale or overheating error codes. Descaling fixes it if it is done before the exchanger is damaged.
The manufacturer sets the schedule. In hard water it is typically about once a year, and descaling is cheaper than any tankless water heater repair it prevents. A water softener or scale treatment upstream can stretch the interval.
Most tankless water heater repair calls come down to a short list, and the unit’s error code usually points at it.
Some tankless parts have to be ordered, and we tell you before we leave whether that is the case. For tank heaters, see our water heater repair page. If the unit fails overnight, our 24/7 emergency line is answered around the clock.
A tankless water heater installed by Bulwark Plumbing carries a 2 year labor warranty, and the manufacturer warranty is registered in your name, not ours, so it follows the house. Repairs carry our one year labor warranty as a baseline.
Manufacturer warranties typically depend on correct installation and on maintenance in hard water, which is another reason every tankless water heater we install gets service valves and a descaling schedule.
It depends on the unit, whether the gas line, venting and electrical have to change, and where it is mounted, so we do not publish a number that would not hold. What you can rely on:
Every technician is a Bulwark employee working under Texas license 47173, never a subcontractor. We cover 52 cities within about 25 miles of the Grapevine shop, including Grapevine, Southlake, Coppell and Trophy Club. Book a tankless water heater estimate online in about a minute, or call for anything leaking.
It can be, for a household that runs out of hot water, wants the floor space back, or plans to stay in the house long enough to benefit. It costs more to install than a tank, often needs a larger gas line and new venting, and needs regular descaling because North Texas water is hard. We give you a written price for both a tank and a tankless water heater so you can compare.
Follow the schedule the manufacturer sets. In hard water that is typically about once a year. Scale on the heat exchanger is the most common reason a tankless water heater starts throwing error codes or losing output.
Often it will not. A gas tankless water heater burns far more gas at full fire than a tank heater, so the line that fed the old tank is frequently too small. An undersized line starves the unit and it delivers lukewarm water or shuts down. We check the gas supply before pricing the installation.
Common causes are scale on the heat exchanger, a clogged inlet filter, an undersized gas line, a flow rate too low for the unit to fire, or an igniter or flame sensor problem. The error code on the unit usually narrows it down, and we read it on the first visit.
Yes. Converting usually means upsizing the gas line, new venting suited to the tankless unit, an electrical outlet for the controls, and service valves for descaling. Where the city requires a permit, we pull it and the installation is inspected.
Yes. Most tankless water heater repair calls come down to scale, an igniter, a flame sensor or a clogged inlet filter. Some tankless parts have to be ordered, and we tell you before we leave whether that is the case.
A tankless water heater installed by Bulwark Plumbing carries a 2 year labor warranty, and the manufacturer warranty is registered in your name so it stays with the house. Repairs carry our one year labor warranty as a baseline.
It depends on the unit, whether the gas line and venting have to change, and where it is mounted. Bulwark Plumbing gives you a written flat price before any work starts, and the invoice matches the quote. We do not publish a number that would not hold for your house.
Tell us whether you want a new tankless water heater or have one that is acting up, and the error code if there is one, and we come back with a window. If anything is leaking, call instead.
Pick a window and have it confirmed while you are still on the page. If anything is leaking, call instead: the line is answered 24 hours a day.