Do Tankless Water Heaters Raise Your Electric Bill? Here's The Real Answer

Do tankless water heaters raise your electric bill? For most homeowners, the answer is no and in many cases, the opposite happens. At Derks Plumbing, we get this question from homeowners comparing electric tankless models to their old storage tank units. The short version: tankless systems use energy differently, not necessarily more of it. This guide breaks down the real tankless heater electric cost, what affects it, and how to know if switching makes sense for your home.

Why Tankless Water Heaters Use Energy Differently

A traditional tank heater keeps 40 to 60 gallons of water hot around the clock, whether you're using it or not. That constant reheating, called standby loss, adds up over a month. A tankless unit only heats water on demand, when a faucet or appliance calls for hot water. No storage tank means no standby loss.

This is the core reason tankless heater utility bill numbers often come in lower than expected. You're paying for hot water only when you actually use it.

Do Tankless Water Heaters Raise Your Electric Bill? What The Numbers Show

Here's where it gets nuanced. Electric tankless units draw a large amount of power in short bursts. Heating water instantly requires more wattage at that exact moment compared to a tank system's slow, steady heating cycle.

• Tank heaters: Lower wattage, but running for longer periods throughout the day.

• Tankless heaters: Higher wattage, but only during actual use.

Because usage is brief, most households still see a lower or similar tankless water heater running cost overall, even with the higher instantaneous draw.

Average Tankless Heater Monthly Cost

While exact numbers depend on your household size and local electricity rates, here's a general comparison:

• Traditional tank heater: Often $30 to $45 per month in energy costs for a typical household.

• Electric tankless heater: Often $20 to $35 per month, largely due to eliminating standby heat loss.

Larger households with multiple simultaneous hot water uses, like a shower and dishwasher running together, will see costs closer to the higher end of that range.

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Factors That Actually Affect Your Tankless Heater Electric Cost

Several variables influence whether your bill goes up, down, or stays about the same:

1. Household Hot Water Demand

More people showering, doing laundry, or running dishwashers at once means the unit works harder and draws more power during those windows.

2. Incoming Water Temperature

Homes with colder groundwater require more energy to raise water to the desired temperature, which increases electricity use.

3. Unit Sizing

An undersized tankless heater struggles to keep up with demand, running less efficiently and costing more. Proper sizing is one of the most important factors in keeping your tankless heater monthly cost predictable.

4. Installation Location

Where the unit is installed affects heat loss and efficiency. Homeowners considering installing tankless water heater outside should know that outdoor units can face temperature swings that slightly affect performance, though proper insulation and placement minimize this.

5. Local Electricity Rates

Your utility provider's rate structure plays a bigger role than most people expect. Even an efficient unit can show higher costs in areas with high per-kilowatt-hour pricing.

Tankless vs. Tank: A Quick Cost Comparison

This comparison shows why tankless systems, despite their higher upfront draw, often win out over time.

How To Keep Your Tankless Heater Running Cost Low

A few simple habits help maximize efficiency:

• Schedule annual maintenance. Mineral buildup reduces efficiency over time, especially in hard water areas.

• Choose the right unit size. An oversized or undersized heater wastes energy either way.

• Space out heavy hot water use. Running the dishwasher and a long shower simultaneously increases peak demand.

• Insulate hot water pipes. This reduces heat loss between the unit and your faucets.

• Flush the system periodically. This keeps heating elements working efficiently and prevents strain on the unit.

Is Switching To Tankless Worth It?

For most households, yes. The combination of eliminated standby loss, longer lifespan, and consistent hot water supply usually outweighs the higher upfront installation cost. Homeowners considering a switch should also factor in proper installation, since incorrect setup is one of the most common reasons a tankless heater electric cost ends up higher than expected.

If you're planning an upgrade, our team offers professional Tankless Water Heater Installation in Eagle Rock, ensuring your unit is sized correctly and installed for maximum efficiency from day one.

Final Thoughts

So, do tankless water heaters raise your electric bill? In most cases, no. While the unit draws more power during use, eliminating standby heat loss usually results in a lower overall tankless heater monthly cost compared to a traditional tank system. The real difference comes down to proper sizing, installation, and household usage patterns. If you're considering an upgrade or want a clearer estimate for your home, Derks Plumbing is ready to help you make the switch with confidence.

Frequently Asked Questions

1. Do tankless water heaters raise your electric bill compared to gas models? 

Electric tankless units typically cost more per month to run than gas tankless units, since electricity rates are generally higher than natural gas rates in most areas.

2. What is the average tankless heater electric cost per month? 

Most households see $20 to $35 per month, though this varies based on usage, unit size, and local electricity rates.

3. Does installing a tankless water heater outside affect the electric bill? 

It can slightly affect efficiency due to temperature exposure, but proper insulation and placement typically minimize any impact on your tankless heater utility bill.

4. How long does it take to see savings on tankless heater running cost? 

Many homeowners notice a difference within the first billing cycle, though full savings become clearer after a few months of typical usage.

5. Can an oversized tankless unit increase my tankless heater monthly cost? 

Yes. An oversized unit can cycle inefficiently, while an undersized one struggles to keep up with demand. Correct sizing keeps costs predictable.