Tankless Water Heater Installation in Phoenix & Scottsdale, priced before we start.
“Endless hot water” is how the brochure puts it, and it is true in a narrow sense. A tankless heater never runs out because it doesn’t store anything to run out of. It heats water as it flows, firing when a tap opens and shutting down when it closes. What the brochure leaves off is the fine print on “endless.” It means endless at a certain flow rate and a certain temperature rise, fed by a gas line big enough to keep up.
Inside is a heat exchanger, a coiled path of metal tubing that a burner or electric elements heat fast enough to bring water from street temperature to shower temperature in the few seconds it takes to pass through. Capacity is measured in gallons per minute, and that number falls as the required temperature rise climbs. Sizing is really a question of how many fixtures run at once in January, when the water coming in from the street is at its coldest.
Phoenix gives tankless an advantage and a problem. The advantage is that there is no tank to corrode, so the classic failure, 50 gallons across the garage floor, mostly disappears. The problem is the water itself. Minerals drop out fastest where water is heated fastest, and a heat exchanger is exactly that place. In Valley hard water, scale narrows those passages until the unit throws error codes, loses output, and, left long enough, fails. An annual descaling prevents it.
Before collecting quotes, look at three things. What fuel does your current heater use, and how thick is the gas pipe feeding it? A typical tank runs happily on a half-inch line, while a whole-house gas tankless usually needs more fuel than that pipe can deliver, which means gas line work. Where would the unit hang, and can it vent outside from there? And how long do you plan to stay? The payback math leans heavily on that last answer.
The honest comparison isn’t tankless against nothing. It is tankless against the next tank you would otherwise buy. When the current heater is already failing, that decision runs on a deadline, and deadlines make for bad arithmetic. Deciding while the old tank still works lets you run the savings numbers calmly, price a straight tank replacement alongside, and schedule the gas and venting work without a cold shower hurrying it along.
When tankless fits the house, and when yours needs service
Staying put for a decade or more
Payback typically lands between 8 and 15 years. Owners who sell in three rarely see it. Owners who stay for 12 or more often do.
The tank lives where a leak would hurt
A hall closet, an attic, a utility room off the kitchen. A wall-hung tankless unit holds very little water, so the flooded-closet ending mostly goes away. In some houses that alone justifies the switch.
Do two showers ever run at once?
Simultaneous demand decides the size. A unit sized for one shower delivers lukewarm water to two, and sizing for the average morning instead of the real peak is where disappointing installs begin.
Error codes, or heat that fades mid-shower
In Valley water, the usual cause is scale in the heat exchanger, and a descale often restores full output. If the unit is several years old and has never been descaled, have it checked before the exchanger itself is damaged.
Hot water takes longer to arrive than it did with the tank
Tankless adds a few seconds of firing time, and a far bathroom adds the length of pipe in between. A recirculation setup handles both, if it is planned at installation.
A softener is in the garage, or about to be
Soft water protects the heat exchanger and stretches the interval between descalings. If you are weighing both, a water softener and a tankless heater make the most sense installed together.
How an installation actually goes
- 01
Sizing, on paper first
Fixture count, peak simultaneous use, and winter incoming temperature produce a flow rate. The flow rate picks the unit. Brand preference comes after.
- 02
Gas, venting, and power
Most gas conversions need a larger supply line, new venting through a wall or roof, and an outlet for the unit’s electronics. Electric models may need panel capacity the house doesn’t have. You hear about all of it before the quote, not during the install.
- 03
Service valves, every time
Isolation valves let the unit be descaled in a short visit without cutting pipe. A tankless heater installed without them turns every flush into a small plumbing project.
- 04
Permit and inspection
Gas and venting work is permitted and inspected. The old tank is drained, disconnected, and hauled away.
- 05
The first descale, on the calendar
In hard water a yearly flush is part of owning the machine, not an optional extra. We note the date so it doesn’t slide into the “been meaning to get to that” pile, where it would keep company with the smoke-detector batteries.
What sets the price
Quoted flat, before we start
The unit is only part of the number. Gas line upsizing, new venting, the distance from where the old tank stood, electrical work for electric models, and whether you add recirculation move it most. You get one flat price covering all of it before work begins, and financing is available on installations.
Financing is available on larger jobsA tankless heater is a very good machine with one chore attached. Agree to the chore and it is hard to beat.
Tankless: questions we get asked
Straight answers, the same ones we give on the phone.
