June 23, 2026

A – Z Guide to Is a Tankless Water Heater Worth It

Is a Tankless Water Heater Worth It for Des Moines Homeowners?

Is a tankless water heater worth it? For most Des Moines homeowners, the answer is yes — but it depends on your household’s hot water habits, your home’s existing setup, and how long you plan to stay in the house.

Here’s a quick look at the key factors:

Factor	Tankless Water Heater	Traditional Tank
Energy efficiency	24–34% more efficient (low use)	Lower efficiency due to standby loss
Lifespan	20+ years	10–15 years
Hot water supply	Unlimited, on demand	Limited by tank size
Upfront investment	Higher	Lower
Space required	Very compact (wall-mounted)	Requires floor space
Iowa winter performance	Requires proper sizing	Less affected by incoming water temp

If your water heater is aging, your utility bills feel high, or you’re tired of cold showers when the whole family is home — a tankless system might be exactly what you need. But there are real trade-offs to understand before you decide.

In Greater Des Moines, factors like hard water, cold incoming water temperatures in winter, and your home’s gas line capacity all play a role in whether a tankless unit will perform the way you expect. This guide walks you through everything — from how these systems work to long-term savings, installation needs, and maintenance — so you can make a confident, informed decision.

Infographic showing tankless vs traditional water heater comparison: efficiency, lifespan, hot water supply, and

How On-Demand Systems Compare to Traditional Tanks

To understand if a tankless system is a smart upgrade for your home, it helps to look at how these systems operate under the hood.

Traditional storage tank water heaters typically hold between 20 and 80 gallons of hot water. They work on a simple principle: they heat that entire volume of water and keep it hot 24 hours a day, 7 days a week, regardless of whether you are sleeping, at work, or on vacation. This continuous heating process leads to what the industry calls standby energy loss. It is the plumbing equivalent of leaving your car idling in the driveway just in case you decide to go for a drive later.

Tankless water heaters, on the other hand, do not use a storage tank. Instead, they are incredibly compact—typically about two feet tall and two feet wide—and are mounted directly to a wall. When you turn on a hot water faucet somewhere in your home, cold water travels into the unit. A flow sensor registers this movement and immediately fires up a high-powered heat exchanger, which is heated by either a gas burner or an electric element. The water is heated instantly as it flows through the coiled pipes of the heat exchanger, delivering hot water to your tap within seconds. Once you turn off the faucet, the unit shuts down completely, consuming zero energy.

This architectural difference directly impacts how we measure their performance. While a traditional tank’s capacity is measured in gallons, a tankless water heater’s capacity is measured by its flow rate, which is calculated in gallons per minute (GPM.)

Gas-fired tankless models generally provide higher flow rates, typically ranging from 5 to 10 GPM. Electric tankless models are slightly more limited, usually delivering between 2 to 5 GPM. If you are comparing different setups for your home, exploring the variety of Water Heater Types Des Moines IA can help you visualize which power source and delivery style fits your property’s infrastructure.

Sizing and Flow Rate for Large Families

For larger households, sizing is everything. Because a tankless system does not have a pre-heated reservoir of water to draw from, its ability to supply hot water to your entire home depends on how many fixtures you want to run simultaneously.

If you have a busy morning routine where the dishwasher is running, a load of laundry is washing, and two people are taking showers at the same time, you create a high peak demand. If your tankless system is undersized, it will struggle to distribute enough heat, resulting in lukewarm water or a sudden drop in water pressure.

To size a system correctly, we have to look at two main factors:

Peak Flow Rate: The combined GPM of all hot water fixtures you expect to run at the exact same time. For example, a standard showerhead uses about 2.0 GPM, a kitchen faucet uses 1.5 GPM, and a washing machine uses 2.0 GPM.
Required Temperature Rise: This is the difference between the temperature of the cold water entering your home from the municipal supply and your desired output temperature (usually set between 120 and 140 degrees Fahrenheit.)

In Iowa, groundwater temperatures can drop significantly during the winter. This means your tankless system has to work much harder to heat incoming water up to a comfortable shower temperature than it would in a warmer climate. A unit that easily delivers 8 GPM in the middle of summer might only be able to output 4 or 5 GPM in the dead of winter because of the steep temperature rise required.

Another technical detail to keep in mind is the “cold water sandwich” effect. This occurs when you turn a hot water faucet on, turn it off briefly, and then turn it back on. A small pocket of cold water that was sitting in the plumbing lines between the heater’s activations can flow through to your tap, resulting in a brief, unexpected burst of cold water. Modern high-efficiency tankless units often include small internal buffer tanks or advanced modulating burners to eliminate this issue entirely.

To dive deeper into how these sizing calculations and flow rates work, check out our Tankless Water Heaters Complete Guide.

Weighing the Pros and Cons: Is a Tankless Water Heater Worth It?

compact tankless water heater saving space in a utility room

When deciding if a tankless water heater is a wise investment, it is best to weigh the practical advantages against the real-world limitations.

The Pros

Endless Hot Water: Since water is heated on demand, you will never run out of hot water. You can take a shower immediately after your teenager, while the washing machine is running, without worrying about the water turning icy.
Significant Space Savings: Because they are wall-mounted and compact, tankless units free up valuable floor space in your basement, utility room, or closet. This is a major benefit for homeowners looking to reclaim square footage for storage or remodeling.
Longer Lifespan: A traditional tank water heater typically lasts between 10 and 15 years before the tank begins to corrode. Most tankless water heaters have a life expectancy of more than 20 years because they are built with durable, easily replaceable parts.
Lower Risk of Water Damage: Traditional tanks hold tens of gallons of pressurized water. When they fail, they often rust out at the bottom and flood your basement. A tankless unit holds very little water at any given moment, greatly reducing the risk of catastrophic water damage.

The Cons

Higher Upfront Investment: The technology inside a tankless unit is highly sophisticated, and retrofitting a home to accommodate one requires professional plumbing and venting modifications, making the initial installation more costly than a simple tank replacement.
Power Outages: If the power goes out, your tankless water heater will not produce hot water. Even gas-fired tankless units rely on electronic control boards and electronic ignition systems to operate. In contrast, an old-school gas tank water heater with a standing pilot light can still provide hot water during a blackout.
Vulnerability to Hard Water: Because the heat exchangers in tankless units operate at incredibly high temperatures, mineral scale can form quickly if you have hard water, requiring consistent maintenance.

If you are currently dealing with a failing system and trying to decide whether to stick with a traditional model or make the jump to on-demand heating, our Water Heater Replacement Guide is an excellent resource to help you navigate your options.

Evaluating Long-Term Energy Savings: Is a Tankless Water Heater Worth It?

One of the most compelling arguments for switching to an on-demand system is the reduction in your monthly utility bills. Because tankless water heaters completely eliminate standby energy loss, they are vastly more efficient than their storage-tank counterparts.

According to data from the U.S. Department of Energy:

For homes that use 41 gallons or less of hot water daily, tankless water heaters can be 24% to 34% more energy efficient than conventional storage tank models.
For busier households that use around 86 gallons of hot water per day, they are still 8% to 14% more energy efficient.

These efficiency gains translate directly into financial savings. For example, an ENERGY STAR® certified gas tankless water heater can save a typical family of four about $95 per year on gas bills compared to a standard gas storage tank model. Over the course of the system’s 20-plus-year lifespan, these annual savings—combined with the fact that you won’t have to buy a replacement system halfway through—can help offset the higher initial installation costs.

Additionally, homeowners in 2026 can take advantage of federal tax credits and local utility rebates designed to encourage energy-efficient upgrades.

Under current federal guidelines, qualifying ENERGY STAR® certified gas tankless water heaters may eligible for a 30% federal tax credit, making the initial transition much more manageable. To see how these efficiency ratings stack up and how they impact your carbon footprint, read about why tankless systems are considered the Tankless Water Heaters Efficient Choice.

Installation and Maintenance Requirements in Iowa

Installing a tankless water heater is not a simple DIY project. Because these systems pack a massive amount of heating power into a small space, they have strict installation requirements that must be handled by a licensed professional.

First, gas-fired tankless units require a significant amount of fuel to heat water instantly. A standard tank water heater might run on 40,000 BTUs, while a whole-home tankless unit can require up to 200,000 BTUs. This means your existing gas lines and your gas meter may need to be upgraded to handle the higher load when the unit fires up. If the gas line is undersized, the unit may trigger low gas pressure error codes and fail to deliver hot water.

Second, venting is critical. Non-condensing tankless units exhaust extremely hot gases, requiring expensive stainless-steel venting. Condensing tankless water heaters, however, use a second heat exchanger to cool the exhaust gases and capture extra heat. This lowers the exhaust temperature enough that the system can be safely vented through inexpensive PVC pipes, which is often much easier to route through an exterior wall.

If you want to know what to expect during the installation process in our local area, our Tankless Water Heater Installation Des Moines Guide outlines the exact steps and local building codes we follow.

Managing Hard Water and Iowa Winters: Is a Tankless Water Heater Worth It?

Living in Iowa means dealing with two major environmental factors that directly affect water heater performance: hard water and freezing winters.

The municipal water supply in many parts of Greater Des Moines contains high levels of calcium and magnesium. When hard water is heated inside a tankless unit’s heat exchanger, these minerals solidify and form scale. Over time, this scale acts as an insulator, forcing the heat exchanger to work harder and run hotter to heat the water. If left unaddressed, mineral buildup will restrict water flow, reduce energy efficiency, and eventually cause the heat exchanger to overheat and crack.

To protect your investment, regular maintenance is non-negotiable. This involves an annual flushing process where a mild, food-grade descaling solution is pumped through the unit to dissolve the mineral deposits. If you have extremely hard water, pairing your tankless system with a whole-house water softener is highly recommended to extend the lifespan of your equipment.

Iowa winters also put extra stress on water heaters. When the ground freezes, the temperature of the incoming water drops significantly. Your tankless system must perform a much larger “temperature rise” to reach your target output. This means proper sizing by a local expert who understands Iowa’s climate is essential. A system sized for a home in a southern state will fail to deliver adequate hot water during a freezing January in West Des Moines or Ankeny. If you ever run into performance issues during the winter, you can learn more about troubleshooting and professional repairs in our guide to Tankless Water Heater Repair Des Moines IA.

Frequently Asked Questions About Tankless Water Heaters

How long do tankless water heaters last compared to tank models?

Most tankless water heaters have a life expectancy of more than 20 years when they are properly maintained. In comparison, traditional storage tank water heaters typically last between 10 and 15 years. Because tankless units are built with individual, replaceable components, a technician can easily swap out a worn-out part to extend the system’s life. With a traditional tank, once the inner lining rusts or cracks, the entire unit must be replaced. If you are trying to determine if your current system is on its last legs, read our article on the Signs Your Water Heater Is Going Out.

Can a tankless water heater freeze during Iowa winters?

Yes, if not properly installed or protected, a tankless water heater can freeze. However, modern high-quality tankless units come equipped with built-in freeze protection heaters that prevent the internal water lines from freezing, provided the unit remains plugged in and has electrical power.

Additionally, professional installers use specialized wind-resistant vent terminations and insulate all exposed water pipes to ensure cold winter drafts do not compromise the system.

Do tankless water heaters require annual maintenance?

Yes. To maintain your manufacturer’s warranty and keep the system running efficiently, tankless water heaters require regular maintenance. In hard water areas like Des Moines, we recommend an annual flushing and descaling service to remove mineral deposits from the heat exchanger. The unit’s inlet water filter should also be checked and cleaned periodically to ensure steady water flow.

Conclusion

So, is a tankless water heater worth it? For homeowners in Greater Des Moines who plan to stay in their homes for several years, value endless hot water, want to reclaim basement space, and want to lower their monthly energy bills, the long-term benefits of a tankless system make it an outstanding investment.

However, because these systems require precise sizing, adequate gas line capacity, and proper venting to handle Iowa’s cold winters and hard water, a professional assessment is the only way to guarantee you get the performance you deserve.

At True Comfort Heating, Cooling and Plumbing, we are dedicated to keeping your home comfortable and efficient. We serve families across the entire Greater Des Moines area—including Waukee, Ankeny, West Des Moines, Urbandale, Johnston, Altoona, Pleasant Hill, and Bondurant—with honest assessments, dependable service, and flexible maintenance plans. We treat our customers like family, which is why we offer unique perks like crediting your maintenance fees toward new equipment upgrades.

If you are ready to explore your options and find the perfect water heating solution for your home, Schedule a professional water heater consultation with True Comfort today!