Tankless installation cost varies more than almost any other plumbing project, because the unit itself is often less than half the total. What drives the price is what your house needs in order to accept one. We quote after looking, not over the phone.

The Five Things That Set the Price

  • Gas supply capacity. This is the big one. A tankless water heater fires at a far higher input rate than a tank unit — often three to five times higher. Many homes have a gas line sized for the old tank and nothing more. Upsizing that run is frequently the single largest line item.
  • Venting. Tankless units require their own venting, usually stainless steel or sealed PVC depending on the model. The old flue almost never works.
  • Location. Relocating the unit — a common choice, since tankless heaters are small enough to hang on a wall or move outside — means rerouting water, gas, and vent.
  • Electrical. Even gas tankless units need power for controls and ignition.
  • Water treatment. In hard water, a softener or scale filter is not optional if you want the unit to survive.

Why Gas Line Work Surprises People

A homeowner sees a tankless unit priced comparably to a good tank heater and reasonably assumes the project will cost about the same. Then the estimate comes in significantly higher, and it feels like padding.

It is not. A tank water heater sips gas continuously to keep forty gallons warm. A tankless unit heats water instantaneously, on demand, which requires an enormous burst of gas whenever someone opens a hot tap. If the supply line cannot deliver that volume, the unit will underperform, throw error codes, or fail to reach temperature — and it will do it intermittently, which is maddening to diagnose.

We calculate the total gas load for the house, including the furnace, range, and dryer, and size the line for the actual demand. Where gas line work is required, it goes in the estimate up front.

Hard Water Changes the Economics

Hill Country water is hard, and a tankless heat exchanger is exactly the wrong place for mineral scale. The passages are narrow, the temperature differential is high, and scale accumulates fast.

An unprotected tankless unit in hard water can lose efficiency within a couple of years and fail well short of its expected twenty-year life. That turns a good investment into a bad one. Pairing the installation with a water softener adds cost, but it is the difference between a unit that lasts two decades and one that does not make it to eight.

We will tell you plainly if we think your water makes tankless a poor value without treatment.

Where the Money Comes Back

Operating cost is the return. A tank heater reheats its stored water around the clock whether you use it or not — standby loss you pay for every day. A tankless unit consumes gas only while hot water is running.

Lifespan is the larger factor. A well-maintained tankless unit commonly runs twenty years or more, roughly double a tank heater. Amortized over that period, the higher installed cost usually comes out ahead, and you skip one full replacement cycle along the way.

When a Tank Is the Better Buy

We do not push tankless on everyone. If your gas supply is badly undersized, venting is difficult, and the household is two people with modest hot water use, the payback stretches out far enough that a quality tank water heater is the smarter purchase.

The households that benefit most are larger families running simultaneous fixtures, homes short on utility space, and anyone tired of running out of hot water.

Getting a Real Number

Our estimate includes gas sizing, venting, electrical, permits, and any water treatment we recommend — itemized, so you can see what is required versus what is optional. Estimates are free and financing is available.

Ongoing water heater maintenance is what protects the investment, and we will show you the descaling schedule before you buy.

We serve Fredericksburg, Kerrville, Boerne, Comfort, and the surrounding Hill Country. For an on-site estimate, contact 72 Degrees or call (830) 468-5316.