Water heating
Tankless Water Heaters in Boerne, TX: Gas Capacity, Demand and the Maintenance They Need
Installation, descaling and repair. Also an honest answer about whether tankless is the right call for your property, because frequently it is not.
Or call (833) 571-0120 and describe what you are seeing.
What tankless actually changes, and what it does not
A tankless unit heats water as it flows rather than keeping a tank hot. The genuine benefits are that you cannot run out, and that you are not paying to keep forty gallons warm overnight. Both are real. For tankless water heaters, Boerne homeowners need to look at the gas line and the vent route before the unit itself.
What it does not change is flow rate. A tankless unit delivers a certain number of gallons per minute at a given temperature rise, and if you ask for more than that the temperature drops. People who are disappointed by tankless have usually been sold one that was sized for the brochure rather than the household.
If a conventional tank is the better answer for your property, we will say so. That work is on our water heater replacement page, and a tank is frequently the more sensible spend.
Gas line, venting and electrical capacity decide if tankless fits
| Factor | Why it decides the job | What usually happens |
|---|---|---|
| Gas line capacity | A gas tankless draws far more than a tank; an undersized line starves it | The run frequently has to be upsized from the meter |
| Venting | Needs its own dedicated sealed vent, not the old flue | New vent route through a wall or roof |
| Electrical capacity | An electric whole-home unit needs substantial dedicated capacity | Often rules out electric whole-home on an older panel |
| Incoming water temperature | Temperature rise determines flow; colder in means less hot out | Milder winters here help, but sizing still has to be real |
| Simultaneous demand | Two showers plus a dishwasher is the test, not total daily use | Decides the model, or decides against tankless |
Gas sizing and venting are where most of the cost lives on a tankless conversion, not in the unit. Anyone quoting a swap price without having looked at the gas run and the vent route has not quoted the job.
Descaling a tankless unit and how scale shortens its life
A tankless heat exchanger has narrow passages, and mineral scale narrows them further. A scaled unit loses output, runs harder and eventually errors out. Descaling is routine maintenance rather than a repair, and it is the single thing most likely to decide whether a tankless unit reaches its rated life.
How often depends on your water, and the honest local picture is more mixed than the usual sales line. The City of Boerne's 2025 drinking water quality report, system TX1300001, puts the supply at roughly 79 percent surface water, mostly purchased from the Western Canyon project at Canyon Lake, with about 21 percent groundwater from the Trinity Group aquifers. A property on city supply is not running on straight limestone groundwater. A property on a private well out past the city system frequently is, and those units need descaling considerably more often.
The number we are not quoting you
We have not published a hardness figure for Boerne because we could not confirm one from the city's own report, and the figures circulating locally come mostly from companies selling water treatment. Boerne Utilities will give you the current number on (830) 248-1538, or we can test at the tap. If you are on a well, testing is worth doing regardless, and the hard water treatment page covers what to do about the result.
Point-of-use units under a sink
A small undersink tankless unit solves a specific and common irritation: a tap a long way from the water heater where you run several liters cold before anything warm arrives. Fitting a point-of-use unit at that fixture gives near-instant hot water there without touching the main system.
They suit a guest washroom, an outbuilding, a workshop sink or a kitchen tap at the far end of a long run. They are not a substitute for a whole-home unit and we would not sell one as though it were. Where the problem is the wait rather than the capacity, this is frequently the cheaper and better answer.
Where a point-of-use unit earns its place
- A fixture that is a long pipe run from the main heater
- An outbuilding, workshop or garage sink with no practical hot supply
- A guest bathroom used rarely enough that keeping the run hot makes no sense
- A utility sink where a modest flow is all that is needed
Check the gas run and vent route before committing to tankless
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Before you commit to tankless, it is worth half an hour on site looking at the gas run and the vent route. That is where the real cost sits.
Call (833) 571-0120Tankless questions from Boerne
Is a tankless water heater worth it here?
It depends on demand and on what the property can support. If you regularly run out of hot water, or you want to stop paying to keep a tank warm, the case is good. If the gas line needs upsizing from the meter and a new vent route has to be cut, the conversion cost can be several times the unit price, and a correctly sized tank may serve you better. We will look at the gas run, the vent and the panel and give you the real number rather than the brochure one.
What does a tankless installation cost in Boerne?
Meaningfully more than a tank replacement, and the spread is wide because the variables are gas line sizing, electrical panel capacity and the exterior venting configuration rather than the appliance itself. Our cost page carries wide ranges for both tankless and tank installations so you can see the gap before you decide. We quote after seeing the property.
Do I need a permit for a tankless installation?
Normally yes, and more clearly than for a like-for-like tank swap, because the work usually involves gas and venting changes. Boerne has adopted the 2021 International Plumbing Code along with the 2021 mechanical and fuel gas codes and the 2023 National Electrical Code, and contractors must be registered with the city to submit permit applications. Permitting and Code Compliance at 447 N. Main Street will confirm your job on (830) 248-1529, and we handle the application.
How often does a tankless unit need descaling?
Annually is the common manufacturer guidance, and whether you need it more or less often depends on your water. Properties on private wells with heavier mineral loads generally need it more frequently; properties on the city's largely surface-water supply often less. Rather than guess, we would test your water and set an interval from the result. Skipping it entirely is the most reliable way to shorten the life of the unit.
How do I verify a plumber's license before gas work?
The Texas State Board of Plumbing Examiners licenses plumbers in this state and publishes a lookup anyone can search, so you can check a license number yourself. Boerne also requires contractors to be registered with the city to work within city limits. For anything involving a gas line, asking both questions before work starts is simply sensible.
Weighing up tankless?
Tell us the gas supply, the panel, and how many bathrooms run at once. That is most of the feasibility answer.