Tankless water heater and installation cost

Looking for tankless water heater and installation cost in St. Louis, MO? Call WaterHeater Experts for a contact a provider — no obligation. Licensed plumbers serve St. Louis and the surrounding area, and you'll get straight answers on timing and what affects the price.

Last updated: September 24, 2026

Need help right now? If your water heater is leaking or you have no hot water, do not wait for the problem to get worse. Water damage spreads fast, and we are ready to help right now. We know how stressful an emergency can be, so we focus on getting you connected to someone who can fix the issue immediately. Pick up the phone and let us help you get back to normal. (978) 759-4817

What affects the price

When you are looking at the price of a new water heater, a few main things shift the final number. The type of unit you choose—whether it is a tank model or a tankless system—is the biggest factor. You also have to consider the fuel source, like gas or electric, and the physical space where the heater sits. If your home needs new venting, updated piping, or a different hookup to meet current safety codes, that adds labor time to the project.

About this service

When calculating the cost of a tankless water heater and the labor to install it, we consider the unit's flow rate and your home’s existing utility connections. Upgrading to this technology usually requires specific venting and plumbing modifications that impact the total price. We ensure the system is properly sized for your family’s water usage. Exact pricing confirmed free on the call.

Even though it is warm outside, your water heater is still working daily. Summer is a great time to adjust your settings, as the incoming water isn't as cold, which can actually help extend the life of your unit. If you are planning a home renovation or just want to upgrade to a more efficient model, call us to talk through your options.

Frequently asked in St. Louis

How long do hot water heaters typically last?

In the St. Louis area, standard tank water heaters generally last 10-15 years. Tankless water heaters, with proper maintenance, can often provide hot water for 20 years or more. Signs of aging include rust or leaks.

What is the average cost of putting in a water heater?

What is the most efficient type of water heater?

Tankless water heaters are usually the most efficient, heating water only when you need it, which can lead to energy savings. High-efficiency tank models also offer good performance. Consider your household's water usage patterns.

What are signs I need a new water heater?

You might need a replacement if you have a reduced hot water supply, hear strange noises, or notice leaks or corrosion. If your unit is over a decade old, it's wise to consider replacement. A professional assessment can confirm.

What is the most common problem with a hot water heater?

Sediment buildup in the tank is a frequent issue that can impact performance and cause noise. Other common problems include thermostat failures, heating element malfunctions, or anode rod deterioration. These are typically manageable by skilled pros.

Is it worth it to repair a hot water heater?

Also serving nearby: O Fallon · Springfield · Columbia · Champaign · Peoria

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More on this: DOE water heating — efficiency and sizing.