Tankless Water Heater Installation in Austin, TX

Installing a tankless water heater is not a swap. The tank comes out, and what replaces it needs a gas line that can feed it, a sealed vent to the outside, a condensate path, a power outlet, and isolation valves so it can be serviced. Skip any one of those and you get a unit that either short-cycles, throws codes in winter, or cannot be maintained without a plumber cutting into copper.

We quote all of it up front. The sizing visit takes about thirty minutes: we check the gas meter and line size, measure the run to a suitable exterior wall, look at your panel if the unit is electric, and count what actually runs at once in your house on a January morning.

What a full installation includes

On-site sizing — gas line, vent route, electrical capacity and peak demand
City plumbing permit pulled under our license, inspection attended
Gas line upsize to 3/4-inch where the unit requires it
Sealed concentric or PVC venting to code, with proper clearances
Condensate drain and neutralizer on condensing units
Service isolation valves so the unit can be flushed annually
Old tank drained, disconnected and hauled away
Controller setup, temperature limit set, and a walkthrough before we leave

Plumber mounting a new tankless water heater on a utility room wall

How the day goes

1

Call or send the form

Tell us the house, the fuel, and what is going wrong. Most quotes need five minutes on the phone and a photo of your current heater.

2

On-site sizing visit

We check gas line size, venting route, electrical capacity and your peak hot water demand, then put a fixed price in writing.

3

Installation day

Most changeovers take four to eight hours. Gas line or venting upgrades can add a day. We protect floors and haul the old tank away.

4

Inspection and handover

We meet the city inspector, walk you through the controller, and set your first descaling reminder.

Good reasons to make the switch

Your tank is past ten years old and you would rather not gamble on the next winter
You want the garage floor space back — a tankless unit lives on the wall
The house runs out of hot water when two people shower back to back
You are tired of paying to keep 50 gallons hot around the clock in a 100°F garage
You are remodeling and moving the heater location anyway
A slab or garage flood from a failed tank is a risk you do not want to carry

What installation costs in the Austin area

Scope of work	Typical range
Gas tank to gas tankless, existing 3/4-inch line, easy vent	$3,200 - $4,200
Gas tank to gas tankless, gas line upsize required	$4,200 - $5,500
Tankless to tankless replacement, same location	$2,000 - $3,400
Second unit for a large or multi-zone home	$2,800 - $4,000
Electric point-of-use unit for a bathroom or addition	$650 - $1,400
Attic or crawlspace relocation to garage wall	add $400 - $900

Estimates, not quotes. Planning ranges for a typical single-family home, permit included. Your written quote is fixed before work starts.

What is specific to installing tankless in Austin

Gas line size is the number one cost driver here. Austin homes built before the 1990s were commonly plumbed with a half-inch line to the water heater, sized for a 40,000 BTU tank. A 199,000 BTU tankless unit needs 3/4-inch, sometimes a meter upgrade from Texas Gas Service. We check that before quoting, not after starting.

Venting is the second. Condensing units use PVC and can run longer, which matters in two-story homes where the heater sits in an interior closet. Non-condensing units need stainless and a short run to an exterior wall, which usually means the garage.

Texas Gas Service has historically offered residential rebates for high-efficiency tankless equipment in its Austin service territory. Programs and amounts change year to year, so ask us for the current form rather than trusting a number you read somewhere.

Frequently asked questions

How long does the installation take?

Four to eight hours for a straightforward gas changeover. If the gas line needs upsizing or the vent has to go through a two-story wall, plan on a full day and occasionally a second morning. We tell you which one you are before the day starts.

Will I be without hot water overnight?

Almost never. Single-day installs are finished with hot water running the same evening. On the rare two-day job we leave the old tank connected overnight where it is physically possible.

Can the unit go outside?

It can, and in Austin we usually recommend against it. Outdoor units rely on electric freeze protection, which fails during exactly the kind of grid event that causes the freeze. A garage wall with a short vent run is the better location nine times out of ten.

What brand do you install?

We install the major condensing brands — Rinnai, Navien, Rheem and Noritz — and choose based on your gas line, vent route and demand rather than on what we bought in bulk. If a brand is wrong for your house we will say why.