Tankless Water Heaters in Austin, TX

Endless Hot Water, No Tank in the Attic

Tankless installation, descaling and repair for Austin homes, with the gas line, venting and freeze protection done right the first time.

Austin Tankless Water Heaters

What Tankless Has to Get Right in Austin

Tankless water heaters are a good fit for a lot of Austin houses. They take the tank out of the attic in a Round Rock or Cedar Park two-story, they keep up with a household that runs showers back to back, and in the new all-electric and gas subdivisions in Leander, Hutto and Manor they are often already on the garage wall. But three local things decide whether a tankless unit is a pleasure or a headache, and all three get skipped when the install is rushed.

The first is hard water. Austin’s lake-fed supply and the well water in Dripping Springs and Spicewood leave scale on a tankless heat exchanger the same way they crust a tank, and a unit that is never descaled loses output and throws error codes within a few years. Isolation valves and an annual flush solve that. The second is gas supply: the half-inch line that fed the old tank in a 1990s Pflugerville home usually cannot feed a tankless burner, and undersized gas is the most common cause of lukewarm water from a new unit. The third is freezing. Exterior-mounted tankless units rely on electric freeze protection, and when the power went out for days in February 2021, many of them froze and split. We plan for all three on every install. The basics of how tankless works are on our tankless water heaters page.

  • Gas line sized to the burner We measure the run and upsize the line when the old one cannot carry the load.
  • Isolation valves on every install So the unit can be descaled every year without cutting pipe.
  • Planned for a hard freeze Location, drain-down and freeze protection chosen with February 2021 in mind.
Radiant technician walking up to a modern Austin home for a tankless water heater estimate

Is Tankless Right for You?

When Austin Homeowners Switch to Tankless

These are the situations where a tankless unit earns its higher upfront cost. If none apply, a good tank may still be the better buy, and we will say so.

  • The tank is in the attic and you want it gone

    A wall-hung tankless on the garage side removes forty-plus gallons from above your ceiling. The most common reason for the switch in Austin suburbs.

  • The third shower is always cold

    A tankless unit sized for your flow does not run out. A bigger tank just runs out later.

  • You are remodeling or adding a bath

    A remodel is the cheapest time to run the gas, vent and condensate a tankless needs, especially in a central Austin house where the closet is going away.

  • The new house has one and it is not performing

    Builder-installed units in Leander, Kyle and Hutto often ship without isolation valves and have never been flushed. Scale is the usual reason.

  • Your existing tankless shows an error code

    Flow sensors, igniters and scaled heat exchangers are repairable. We diagnose before anyone suggests a new unit.

  • Hot water is lukewarm on cold mornings

    In January the incoming water is cold enough that an undersized or gas-starved unit cannot lift it far enough. Sizing and gas supply fix it.

Tankless Services

Tankless Work We Do Across the Austin Area

Installation, conversion, annual descaling and repair, on gas and electric units.

Radiant plumber with a tool bag beside a service van at an Austin tankless installation
Tankless water heater installation, repair and maintenance across the Austin area.
  • Tank-to-tankless conversion Removing the old tank, upsizing gas, running the vent and condensate line, adding the electrical outlet and mounting the unit where it can be serviced.
  • Gas line upsizing From the meter or the nearest properly sized branch, pressure-tested and permitted. See gas lines.
  • Annual descaling A vinegar or descaler flush through the isolation valves, plus inlet screen and air filter cleaning. The single most important service in Austin water.
  • Tankless repair Flow sensors, igniters, flame rods, fans and control boards, on units of any brand. Diagnosed from the error code and tested, not swapped on a guess.
  • Retrofitting isolation valves For builder installs that never had them, so the unit can be flushed properly from now on.
  • Softener and scale protection A softener or inline scale filter ahead of the unit slows buildup between flushes. More at Austin water softeners.

How a Tankless Install Goes

From Estimate to Endless Hot Water

The planning is where a tankless install succeeds or fails. We do not skip it.

  1. Measure the house

    Fixture count, peak flow, gas meter capacity and line size, vent path, electrical and the mounting location, inside or out.

  2. Size the unit and price it in writing

    The unit, the gas and vent work, the permit and any softener option, itemized and honored for 72 hours. No hidden fees.

  3. Install and commission

    Old tank out, new lines in, unit mounted with isolation valves, then set up and tested at every fixture under a permit where required.

  4. Set the descaling schedule

    We show you the isolation valves, explain the annual flush, and Care Club members get it folded into their plan.

Thinking About Tankless in Austin?

Get an honest sizing and a written price, with no interest and no payments for six months, subject to credit approval.

What Our Customers Say

Don't just take our word for it — hear from our satisfied customers

J Jeff Fazio
Jeff Fazio 3 years ago
★★★★★
I had Radiant Plumbing replace my tankless water heater, damaged in the Feb. 2021 snowmageddon storm with a new unit. The process was smooth and professional from start to finish. The plumber, James, was extremely knowledgeable and thoroughly explained my options to me. The cost and time to perform the installation were just as estimated. When he was done, James explained how to maintain the system, what service would be needed and how to perform it, and answered all of my engineering geek questions. It was a thoroughly positive experience. I have used several different plumbers in Austin over the past 15 yrs, but my search is over - I will not hesitate to call Radiant next time and would recommend them unreservedly.

8/9/23 Update: I have subsequently used Radiant for a toilet repair, faucet installation (Danny), and drain work (Ezekiel) and they have continued to impress with knowledgeable, friendly plumbers and quality work.
C Cathy McClaugherty
Cathy McClaugherty 5 years ago
★★★★★
We called Radiant Plumbing after we noticed a water leak in our kitchen. We were in a time crunch and they were able to schedule us quickly, before we left for vacation. They sent their representative, Preston Nichols, and he was excellent to deal with! He was on time, skillful, friendly, and very professional. It turned out to be a problem with our dishwasher but Preston was quick to diagnose it and set our minds at ease. While he was here, we mentioned that our one year-old water heater needed to be flushed. Preston was quick to take care of that, as well, saving us time and money in the process. Radiant charged us almost half the price another plumber quoted us for that service! While Radiant Plumbing isn’t our usual plumber, they gained a new customer. We won’t hesitate to call Radiant again in the future based on our VERY positive experience with them.
S Stefano Rosellini
Stefano Rosellini 6 years ago
★★★★★
Had 3 different systems installed by them approx. 3 years ago for a total of approx $20k. I was quite happy with the install until the year later when they came for a maintenance call and started finding deficiencies in their own install. they wanted extra money to address those deficiencies. Now I am in the process of selling my home and an inspector has found a few items that need to be addressed and they will not even look at the report unless I schedule a $139.00 service call. Very poor customer service.. This company does not stand by their work and would not recommend.

I am revising my review of this business from 1 to 5 stars. After my original review I was contacted by the company's service manager and he made sure that I was taken care off. I had a team of 3 technicians coming to my house to double check the system and make the necessary adjustments. I was very satisfied by their attention to details and professionalism.

Maintenance Membership

Join the Care Club

Home maintenance for $9.99 a month.

Care Club members get two HVAC tune-ups and a plumbing safety inspection every year, priority scheduling, no dispatch fees — ever — and 5% off every repair.

  • Priority scheduling
  • Seasonal HVAC tune-ups
  • Annual safety inspection
  • Exclusive member discounts
  • Free dispatch on repairs
  • No long-term contracts

Austin Tankless Water Heater Questions

Will a tankless water heater freeze during an Austin winter storm?

It can, and February 2021 proved it. Most tankless units have built-in freeze protection, but it is electric, so when the power fails during a hard freeze the protection fails with it. Exterior units and units in unheated garages are the ones at risk. The fixes are practical: mount the unit indoors or in a conditioned space where possible, keep the gas and water lines insulated, and know how to drain the unit if the power goes out during a freeze warning. We walk every customer through the drain-down procedure at install. If an existing unit froze and split in a past storm, the heat exchanger is usually the casualty and we can tell you quickly whether repair or replacement makes sense.

Does my gas line need to be bigger for a tankless in an older Austin house?

Very often, yes. A tank heater burns a modest amount of gas for a long time; a tankless unit burns several times as much for a short time, and the pipe has to deliver that instantly while the furnace and range may also be running. The half-inch or three-quarter-inch line that served the old tank in a 1980s or 1990s Austin-area home is usually too small over the distance involved. The symptom of an undersized line is a unit that lights, runs lukewarm and shuts off. We calculate the load against the meter and the existing piping during the estimate and price any upsizing into the quote, so there is no surprise on install day.

How often does a tankless need to be descaled in Austin?

Once a year for a house on Austin municipal water, and we would not argue with twice a year on Hill Country well water or in a house without a softener. Scale builds on the heat exchanger where the water is hottest, and it insulates the exchanger so the unit works harder and delivers less. The flush takes under an hour with a pump and isolation valves. If the unit has no isolation valves, which is common on builder installs in Leander, Kyle and Hutto, we can add them so future flushes are simple. A softener ahead of the unit slows the buildup considerably but does not replace the flush. Care Club members can add the descaling to their annual plumbing visit.

Is an electric tankless practical for a whole house in Austin?

Usually not for a whole house, and we will say so rather than sell one. Heating water on demand with electricity takes a very large amount of current, and a whole-home electric tankless typically needs multiple dedicated circuits that many Austin panels cannot spare, especially in the all-electric homes in Leander and Hutto that already carry a heat pump and an EV charger. Where electric tankless shines is point-of-use: a single distant bathroom, a garage apartment or a casita on a central Austin lot. For whole-house tankless, gas is the practical choice, and where there is no gas a hybrid heat pump tank is often the better electric option. Our Austin-only electrical team can assess the panel if you want to explore it.

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