--- title: Electric Tankless Water Heaters and Power Quality description: Read about the problems caused by electric tankless water heaters and tools for mitigating them. image: https://library.powermonitors.com/hubfs/White_Papers/White%20Paper%20Header%20Images/Case%20Study%20Electric%20Tankless%20Water%20Heaters%20and%20Power%20Quality.png --- [![PMI\_Logo\_White\_Slogan](https://library.powermonitors.com/hs-fs/hubfs/Branding%20-%20Logos%20and%20Designs/PMI_Logo_White_Slogan.png?width=655&height=175&name=PMI_Logo_White_Slogan.png "PMI_Logo_White_Slogan")](https://powermonitors.com) [![PMI Logo: Tools you Need. People you Trust.](https://library.powermonitors.com/hubfs/PMI_Website/logo.svg "PMI Logo: Tools you Need. People you Trust.")](http://powermonitors.com) [![PMI Logo: Tools you Need. People you Trust.](https://library.powermonitors.com/hubfs/PMI_Website/logo.svg "PMI Logo: Tools you Need. 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Through real-world data and analysis, it demonstrates how the high instantaneous power demands of TWHs can cause voltage sags, flicker, and transformer overloads, especially when multiple units are installed on the same distribution transformer. The paper also discusses mitigation strategies and compares TWHs with traditional electric water heaters, highlighting the unique challenges posed by the widespread adoption of TWHs. Using field data, the paper shows a single tankless unit can draw 20–30 kilowatts (and more at higher flow), causing abrupt step changes and rapid cycling at partial flow that drive light flicker and root-mean-square (RMS) voltage variation. **Key topics include:** \- Introduction to Tankless Water Heaters \- Power Requirements and Load Characteristics \- Voltage Quality Impacts of TWHs \- Real-World Data and Analysis \- Mitigation Strategies for Voltage Problems \- Comparison: Traditional vs. Tankless Water Heaters **Why utilities should care:** Widespread adoption of electric tankless water heaters can lead to transformer overloads, voltage sags, and flicker, impacting service reliability and customer satisfaction. Understanding these effects is crucial for planning, infrastructure upgrades, and maintaining power quality standards. On a 25 kilovolt-ampere (kVA) transformer, a 24–36 kilowatt unit can depress secondary voltage; with multiple homes sharing a transformer, flicker spreads. At low gallons-per-minute (GPM) flows, fast element cycling sustains modulation; at shower flow, continuous high current drives undervoltage. Verify loading with root-mean-square (RMS) min/average/max stripcharts and correlate power steps to usage. Mitigation includes upsizing service conductors or, when necessary, the distribution transformer; monitoring confirms results. Because these appliances are sold and installed without utility notification, screening and customer guidance reduce complaints and protect transformer life. Document seasonal variations, cold-inlet effects, and parallel installations to prioritize upgrades and avoid surprises, service calls. You may also enjoy...   - - - - ## Speakers ### [Alvin Rogers](https://library.powermonitors.com/electric-tankless-water-heaters-and-power-quality#inline-content-1speakers)[Follow me on LinkedIn](https://www.linkedin.com/apex-alvinrogers) Director of Sales Omnicorp Alvin Rogers Director of Sales Omnicorp About Alvin Rogers Alvin Rogers is a highly accomplished and sought-after speaker, renowned for their expertise and captivating stage presence. With a diverse background in \[relevant field or industry\], they bring a wealth of knowledge and experience to every speaking engagement. Their dynamic and engaging style seamlessly combines powerful storytelling with actionable insights, leaving audiences inspired and equipped with practical strategies for success. Alvin has delivered impactful keynote addresses at prestigious conferences and corporate events worldwide, consistently receiving rave reviews for their ability to connect with and energize audiences. Whether addressing topics such as \[specific areas of expertise\], leadership, or innovation, Alvin is dedicated to empowering individuals and organizations to reach their full potential. [LinkedIn](https://www.linkedin.com/apex-alvinrogers) [Facebook](https://www.facebook.com/apex-alvinrogers) [Instagram](https://www.instagram.com/apex-alvinrogers) [Twitter](https://www.twitter.com/apex-alvinrogers) ### [Lisa Smith](https://library.powermonitors.com/electric-tankless-water-heaters-and-power-quality#inline-content-2speakers)[Follow me on LinkedIn](https://www.linkedin.com/apex-lisasmith) Creative Director Megacorp Lisa Smith Creative Director Megacorp About Lisa Smith Lisa Smith is a highly accomplished and sought-after speaker, renowned for their expertise and captivating stage presence. With a diverse background in \[relevant field or industry\], they bring a wealth of knowledge and experience to every speaking engagement. Their dynamic and engaging style seamlessly combines powerful storytelling with actionable insights, leaving audiences inspired and equipped with practical strategies for success. Lisa has delivered impactful keynote addresses at prestigious conferences and corporate events worldwide, consistently receiving rave reviews for their ability to connect with and energize audiences. Whether addressing topics such as \[specific areas of expertise\], leadership, or innovation, Lisa is dedicated to empowering individuals and organizations to reach their full potential. [LinkedIn](https://www.linkedin.com/apex-lisasmith) [Facebook](https://www.facebook.com/apex-lisasmith) [Instagram](https://www.instagram.com/apex-lisasmith) [Twitter](https://www.twitter.com/apex-lisasmith) ### [James McGiven](https://library.powermonitors.com/electric-tankless-water-heaters-and-power-quality#inline-content-3speakers)[Follow me on LinkedIn](https://www.linkedin.com/apex-jamesmcgiven) President Minicorp James McGiven President Minicorp About James McGiven James McGiven is a highly accomplished and sought-after speaker, renowned for their expertise and captivating stage presence. With a diverse background in \[relevant field or industry\], they bring a wealth of knowledge and experience to every speaking engagement. Their dynamic and engaging style seamlessly combines powerful storytelling with actionable insights, leaving audiences inspired and equipped with practical strategies for success. James has delivered impactful keynote addresses at prestigious conferences and corporate events worldwide, consistently receiving rave reviews for their ability to connect with and energize audiences. Whether addressing topics such as \[specific areas of expertise\], leadership, or innovation, James is dedicated to empowering individuals and organizations to reach their full potential. [LinkedIn](https://www.linkedin.com/apex-jamesmcgiven) [Facebook](https://www.facebook.com/apex-jamesmcgiven) [Instagram](https://www.instagram.com/apex-jamesmcgiven) [Twitter](https://www.twitter.com/apex-jamesmcgiven) Power Monitors, Inc. is an industry-leading product design and manufacturing firm based in Mt. Crawford, Virginia. PMI strives to solve power quality problems by listening to our customers and working with them to design and manufacture products. Total customer satisfaction is the primary goal of all PMI staff. Please browse our site or call us to learn more about PMI and how we can help meet your power monitoring needs.   800 N Main St Mt Crawford, VA 22841 | Toll Free 800.296.4120 | Fax 540.432.9430 | © 2025 Power Monitors, Inc. ###### Follow Us [Follow us on Facebook](https://www.facebook.com/powermonitors/) [Follow us on LinkedIn](https://www.linkedin.com/company/power-monitors) [Follow us on Twitter](https://twitter.com/powermonitors) [Follow us on Instagram](https://info.powermonitors.com/email-subscribe-page) - [Support](https://powermonitors.com/support) - [Library](https://library.powermonitors.com) - [Training](https://info.powermonitors.com/training) - [Contact](https://powermonitors.com/contact/) - [Products](https://powermonitors.com/products/) - [- Bolt](https://powermonitors.com/product/bolt/) - [- Revolution](https://powermonitors.com/product/revolution/) - [- Seeker](https://powermonitors.com/product/seeker/) - [- Guardian](https://powermonitors.com/product/guardian/) - [Careers](https://info.powermonitors.com/join-pmi) - [Terms and Conditions](https://powermonitors.com/terms-and-conditions/)