Tankless Water Heater Installation
A tankless unit heats water the moment you call for it and never runs out — but only if it's sized to your household's real demand and fed the gas and venting the manufacturer requires. That engineering is the actual product. The box is just hardware.
Why Tankless Installation Is an Engineering Job
A tank water heater stores 40 or 50 gallons and reheats it all day whether you use it or not. A tankless unit does something harder: it takes our region's genuinely cold groundwater — often in the 45–50°F range in winter — and raises it to shower temperature instantly, at whatever flow rate your house demands. That "temperature rise" math is the entire sizing conversation. A unit that handles two showers in Phoenix may struggle with one shower and a dishwasher here, purely because our incoming water starts so much colder.
Getting it right means measuring, not guessing: your simultaneous fixture demand in gallons per minute, your actual incoming water temperature, and — critically — whether your existing gas line can feed a burner several times larger than the tank it's replacing. Many local installations require upsizing the gas supply and installing dedicated stainless or PVC venting, and quotes that skip those line items aren't cheaper, they're incomplete. We spec the full installation up front, so the price you approve is the price that produces endless hot water on the coldest morning in January.
The Details That Decide a 20-Year Result
Tankless units routinely outlast two tanks — when installed to manufacturer specification. The failures we get called to fix elsewhere almost always trace to installation shortcuts: an undersized gas line starving the burner at full fire, improper venting, no isolation valves (making future descaling a plumbing project instead of a 45-minute service), or no plan for the hard-water scale common in local wells. The installer's job is to eliminate every one of those futures on day one.
Gas volume, vent run, clearances, and condensate handled per the unit's book — which also protects your warranty.
Every install includes service valves so annual descaling is quick and inexpensive for the unit's whole life.
On hard well water, we'll tell you honestly whether a scale filter or softener should be part of the plan.
Gas work and venting are permitted, inspected trades — ours passes because it's built to pass.
Why LaVergne's?
Options Around the Tankless Decision
Tankless is a great answer — but not the only one. These are the services that surround the hot water decision honestly.
Heat Pump Water Heater Installation
The efficiency champion for all-electric homes — and currently backed by serious tax credits. We'll compare it against tankless for your situation.
Learn More →Water Heater Installation
Sometimes a quality conventional tank is the right call — simpler, cheaper up front, and well understood. We install those too, without upselling.
Learn More →Gas Line Installation
Upsizing supply for a tankless burner is common here. Our gas fitters run and pressure-test new lines as part of the project.
Learn More →Tankless Water Heater Repair
Already own a tankless that's throwing error codes? Repair and descaling service keeps a good unit going.
Learn More →Whole House Water Filtration
Scale is the natural predator of tankless heat exchangers. Treating hard water protects the investment from day one.
Learn More →Tax Credits & Rebates
High-efficiency water heating qualifies for federal and utility incentives. We'll point you to what applies before you buy.
Learn More →Last One in the Shower Shouldn't Lose.
Get a tankless quote engineered for your household — gas, venting, and sizing included in one honest number.
Is Your Home a Good Tankless Candidate?
Tankless isn't a universal upgrade — it's a targeted one, and it pays off most in specific situations. Households that fit the profile below tend to love the switch for decades; households that don't are often better served by a high-quality tank or a heat pump unit, and we'd rather tell you that in your garage than after an invoice. Here's the honest fit profile.
You Run Out of Hot Water
Back-to-back showers, big soaking tubs, teenagers — if recovery time is your daily frustration, tankless eliminates the concept entirely.
Space Is Worth Something
A wall-mounted unit the size of a carry-on frees the closet or garage corner a 50-gallon tank occupies.
Your Tank Is Near Retirement
The best time to switch is when replacement is already on the table — you're comparing costs forward, not writing off a working tank.
You Plan to Stay Awhile
Tankless economics reward the long hold: higher install cost, then decades of lower standby losses and a lifespan two tanks long.
Tankless Water Heater Installation FAQs
Helpful answers about Tankless Water Heater Installation from the experienced team at LaVergne's.
How is a tankless unit sized?
Two numbers: your peak simultaneous demand in gallons per minute (add up the fixtures that realistically run at once) and the temperature rise required — the gap between incoming groundwater and your target output. Because our winter groundwater runs cold, local sizing needs more capacity than national rules of thumb suggest. We measure both numbers at your home rather than guessing from a chart.
Will my existing gas line work?
Often not without changes — and this surprises people. A tankless burner can demand several times the gas flow of the tank it replaces, and a line sized for the old tank will starve it, causing lukewarm water and error codes at full demand. We calculate the supply during the quote; if an upsize is needed, it's in the price from the start, not a mid-project discovery.
What about our hard well water?
It matters. Scale accumulating in the heat exchanger is the number-one lifespan threat to tankless units, and many well systems in the county carry enough hardness to make treatment worthwhile. Depending on your water, the answer is annual descaling (easy with the isolation valves we install standard), a scale-inhibiting filter, or a softener. A quick water test tells us which.
Electric or gas tankless?
For whole-house duty in our climate, gas (natural or propane) is usually the practical choice — whole-house electric tankless demands enormous amperage that many local panels can't spare. Electric point-of-use units shine in specific spots like a far bathroom or shop sink. If your home is all-electric, a heat pump water heater frequently beats electric tankless on both performance and incentives, and we'll show you that comparison.
How long does installation take?
A straightforward tank-to-tankless conversion typically runs a full day, covering mounting, water connections, venting, condensate, and commissioning. Add gas line upsizing or a long vent run and it can extend into a second day. You'll have hot water again the same day the unit goes live, and we walk you through operation before we leave.
What maintenance does a tankless need?
One thing, mostly: periodic descaling — flushing the heat exchanger with a cleaning solution to remove mineral buildup, annually on hard water and less often on treated or naturally soft supply. It's a quick service through the isolation valves, and it's the difference between a 12-year unit and a 20-plus-year one. We offer it as routine maintenance, and our install manual shows the schedule for your specific water.