What Causes Tankless Water Heaters to Malfunction?
While tankless water heaters are known for their efficiency and longevity, they are not immune to issues. Over time, factors such as mineral buildup, system overload, and improper installation can cause them to malfunction. Understanding these common problems can help you identify issues early and prevent costly repairs:
- Hard Water and Mineral Buildup: Mesa, AZ, has hard water rich in calcium and magnesium, which accumulates inside tankless water heaters. This buildup restricts water flow, reduces efficiency, and can cause heating element failure. Regular descaling and water softeners help prevent these issues, ensuring consistent performance and longevity.
- System Overload: Running multiple appliances simultaneously can overwhelm a tankless water heater, leading to pressure drops and fluctuating temperatures. If your household demand exceeds the unit’s capacity, professional adjustments or an upgraded system may be necessary to maintain a steady hot water supply.
- Ignition or Gas Supply Issues: A tankless water heater depends on an ignition system to heat water instantly. If it fails to ignite, cold water results. Faulty gas lines, sensor malfunctions, or blocked vents are common causes, requiring professional diagnosis and repair to ensure safe operation.
- Error Codes and Electrical Problems: Modern tankless water heaters display error codes for troubleshooting. Some indicate simple maintenance needs, while others signal serious mechanical failures. Ignoring these warnings can lead to complete system breakdowns, making timely inspection and repair essential for uninterrupted hot water supply.
- Cold Water Sandwich Effect: A temporary burst of warm water followed by cold water before reheating is a common tankless heater issue. This occurs when hot water left in pipes runs out before new hot water is heated. Proper system adjustments and maintenance can help minimize this inconvenience.
If you are experiencing any of these common tankless water heater problems, do not wait until your system stops working completely. Call The Cooling & Plumbing Co. today for professional tankless water heater repair in Mesa, AZ!


Our Repair Services: Error Code Troubleshooting, Leak Fixes, and More
At The Cooling & Plumbing Co., we provide comprehensive tankless water heater repair services to ensure your system runs efficiently. Our certified technicians use advanced diagnostic tools to pinpoint the exact cause of the issue and deliver fast, effective repairs:
- Error Code Troubleshooting and System Diagnostics: Tankless water heaters display error codes for issues like water flow restrictions, ignition failures, or overheating. Our experts interpret these codes, inspect the unit, and quickly resolve problems to restore consistent hot water and prevent further damage.
- Tankless Water Heater Flushing and Descaling: Hard water in Mesa, AZ, leads to mineral buildup, reducing efficiency and causing system failures. Our descaling and flushing service removes these deposits, ensuring optimal performance. We recommend annual maintenance to extend your unit’s lifespan and prevent costly repairs.
- Leak Detection and Repair: Water leaks can lower pressure, waste energy, and damage components. Our technicians locate and repair leaks, ensuring your system operates safely and efficiently. Addressing leaks promptly prevents further damage and maintains consistent hot water supply.
- Burner and Ignition System Repairs: A malfunctioning burner or ignition system prevents proper heating. We inspect gas lines, sensors, and ventilation to diagnose and repair ignition issues, ensuring reliable hot water production and preventing potential safety hazards.
- Temperature Adjustments and Flow Rate Optimization: Inconsistent water temperature may stem from improper flow rates or sensor calibration. Our technicians fine-tune settings, adjust flow rates, and recalibrate sensors to ensure your tankless water heater meets your household’s hot water demands efficiently.
For fast and reliable tankless water heater repair in Mesa, AZ, trust The Cooling & Plumbing Co. to get the job done right.
Experienced Plumbers, Advanced Tools, and Exceptional Service
When it comes to tankless water heater repair in Mesa, AZ, you need a trusted local company that understands the unique challenges of Arizona’s water quality and climate. At The Cooling & Plumbing Co., we have over 21 years of experience repairing and maintaining tankless water heaters across the East Valley.
Why Choose Our Repair Services?
- Licensed and Certified Technicians: Our plumbers are trained and certified to work with top tankless water heater brands like Rinnai, Navien, Noritz, and Bosch. Their expertise ensures precise installation, repairs, and maintenance for optimal performance and long-term reliability.
- Fast and Reliable Service: We understand the importance of hot water, so we offer same-day appointments to restore your system quickly. Our prompt service minimizes disruptions, ensuring your home remains comfortable and functional without extended downtime.
- Honest and Upfront Pricing: Transparency is our priority—no hidden fees or surprise charges. We provide clear, upfront pricing so you know exactly what to expect, delivering quality service with integrity and fairness.
- Five-Star Rated Service: Our commitment to excellence has earned us five-star ratings on Google, Yelp, Facebook, Angie’s List, and Nextdoor. Customers trust us for dependable, high-quality service backed by a strong reputation.
- Veteran-Owned and Community-Focused: As a veteran-owned business, we proudly support military personnel, veterans, and first responders with special discounts. Our dedication to the community drives us to provide exceptional service with integrity and care.
When you call The Cooling & Plumbing Co., you are choosing expert service, honest pricing, and guaranteed results.