Installing a Tankless Water Heater in Las Vegas

Installing a tankless water heater in a Las Vegas home is more than unbolting the old tank and hanging a new unit on the wall. A gas tankless heater burns far more gas while it runs than a tank does, so most installs need a larger gas line, new dedicated venting and, because valley water is very hard, a plan to keep scale out of the heat exchanger.

Get those three things right and a tankless unit delivers steady hot water for years. Get them wrong and it short-cycles, throws error codes or scales up early. Here is what a proper installation involves.

Sizing Comes First

A tankless heater is sized by flow, not by gallons stored. The question is how many fixtures will run hot water at the same time, and how much the unit has to raise the temperature of the incoming water. A household that runs two showers and the dishwasher together needs a much larger unit than a couple who rarely overlap.

Las Vegas helps here: incoming water is warm for much of the year, so the unit has less work to do than it would in a cold climate. Winter is the test, so a good installer sizes for the coldest incoming water, not for July. If you are still deciding whether tankless suits your home at all, start with our post on whether tankless water heaters are worth it.

The Gas Line Is Usually the Biggest Change

A tank heater warms its water slowly, so it needs only a modest gas supply. A tankless heater heats water instantly as it flows, and to do that its burner draws several times more gas while it is firing. The half-inch line that fed the old tank is often too small for that load, especially when it also serves a furnace, a range or a dryer.

An undersized line starves the unit: hot water fluctuates, the heater shuts down mid-shower or it shows an ignition fault. So before installation, the gas supply is checked against everything on that line, and where it falls short the run is upsized, sometimes back to the meter. That work is done to code and pressure-tested, and it is part of why tankless installs cost more than tank replacements. Our gas line installation and repair team handles that part of the job, and our post on gas line leak signs covers what to watch for on any gas appliance.

Venting Is Not the Same as a Tank

Most older tank heaters in valley garages vent through a metal flue that relies on natural draft. Most gas tankless units use a sealed, dedicated vent instead, and many high-efficiency condensing models vent through PVC and also need a drain for the condensate they produce.

That means the old flue usually cannot simply be reused. The new vent has to follow the manufacturer's length and termination rules and keep the required clearances from windows, doors and air intakes. On many single-story Las Vegas homes the cleanest route is straight out through a garage side wall.

Plan for Hard Water From Day One

Hard water is the one Las Vegas factor that shortens a tankless heater's life. The Las Vegas Valley Water District puts local water hardness at 291 parts per million, or 17 grains per gallon, which it classes as "very hard". Those minerals drop out as scale when water is heated, and in a tankless unit they collect in the narrow passages of the heat exchanger, cutting efficiency and eventually triggering error codes.

A good installation plans for that up front:

• Isolation valves with flush ports, so the heat exchanger can be descaled without cutting into the plumbing
• A descaling schedule, typically a flush with a pump and descaling solution at the interval the manufacturer recommends for hard water
• Water treatment where it makes sense. A softener or scale-control system protects the heater and every other fixture in the house. Our water treatment page covers the options, and hard water damage in Las Vegas shows what scale does elsewhere in a home.

What Installation Day Looks Like

With sizing, gas and venting planned, the day itself is straightforward. The old tank is drained, disconnected and hauled away. The new unit is mounted, the water lines are connected with service valves, the gas line and vent are completed and tested, and the unit is fired, calibrated and checked at full flow. You should be shown how the unit works, where the flush valves are and when it needs its first descale.

Questions to Ask Before You Book

• Has the installer checked whether the existing gas line can carry the new unit?
• Where will the vent run, and is it included in the quote?
• Is the unit sized for winter incoming water, not summer?
• Will the install include isolation valves for descaling?
• Who pulls the permit?

Book a Tankless Assessment

American Brothers Plumbing sizes and installs gas and electric tankless water heaters across Las Vegas, Henderson and Summerlin, with the gas line and venting handled by the same licensed team. Learn more about our tankless water heater installation or call (702) 704-1776 for a free estimate.