Tankless water heaters power 50–60% of new U.S. homes with endless hot water on demand and can last 20+ years when well-maintained.
Yet even these energy-efficient systems develop faults over time.
Ignoring early warning signs can lead to costly heat exchanger failures or complete system shutdowns.
This blog helps homeowners spot problems with their tankless water heater and know when to call us for expert tankless water heater repair services.
How a Tankless Water Heater Works
Unlike traditional tank units, a tankless water heater heats water only as it flows through the system.
Key components include:
- Heat exchanger: Transfers energy from a gas or electric element to water
- Flow sensor: Detects demand and triggers heating elements
- Ignition system: Lights the burner when a gas supply is required
- Venting assembly: Safely expels combustion byproducts
This on-demand design reduces standby heat loss and keeps energy bills lower, provided mineral buildup and electrical problems are addressed from time to time.
Common Warning Signs
Homeowners often push through minor glitches until the water isn’t hot at all.
Watch for:
- Inconsistent Hot Water Supply – Fluctuating temperatures may signal a failing flow sensor or a clogged heat exchanger.
- Low Water Pressure – Reduced flow often points to scale buildup inside the unit or inlet filters.
- Unusual Noises – Banging, popping, or whining suggest mineral deposits expanding rapidly inside the exchanger.
- Error Codes Displayed – Modern units flash diagnostic codes when gas supply or electrical components fail. Consult your manual or on your own.
- Visible Leaks – Even small drips around fittings can erode seals, leading to bigger leaks and corrosion.
DIY Troubleshooting Steps
Before scheduling a pro visit, try these simple fixes:
- Reset the Unit: Power-cycle electrical models or turn off/on the gas supply for gas units.
- Check Power & Gas Supply: Ensure breakers are on and gas valves are fully open.
- Flush for Mineral Buildup: Every 6–12 months, descaling prevents efficiency loss.
- Clean Inlet Filters: Remove screens and rinse debris under running water.
| Issue | DIY Action | When to Stop |
| Fluctuating Temperature | Reset; flush unit | Error codes persist |
| Low Water Pressure | Clean inlet filter; flush | Pressure <1 GPM after cleaning |
| Error Code (e.g., E02, E03) | Power/Gas cycle; consult the manual | Code repeats after reset |
Call a Professional
Some faults go beyond DIY:
- Complex Gas-Line or Venting Repairs – Improper venting risks carbon monoxide buildup.
- Electrical Faults – Replacing control boards or heating elements requires a licensed technician.
- Persistent Error Codes – Codes that reappear after reset often mean sensor or circuit failures.
- Major Component Failure – Cracked heat exchangers or damaged pressure relief valves need specialized tools.
Our certified plumbers diagnose and fix these issues safely.
Our Inspection
When you book a professional tankless water heater repair, the first step is a full diagnostic inspection.
We start by reading any error codes on your unit. Then we test gas pressure and check for leaks. A pressure drop test follows. This helps us spot hidden issues before they become emergencies.
You’ll know exactly what’s wrong and what needs fixing.
Next comes the hands-on work. We use high-pressure flushing to remove mineral buildup.
Then we replace worn parts like igniters, flow sensors, or pressure relief valves.
We also inspect and adjust venting and combustion-air pathways.
Finally, we run a performance test. We verify water pressure and temperature stability. We leave no loose ends.
With our expert service and manufacturer-backed warranties, your heater will run safely and reliably.
Repair Costs vs. Full Replacement
Understanding pricing helps you decide when to repair or replace:
| Repair Issue | Typical Cost Range (Labor + Parts) |
| Sensor or Igniter Replacement | $150 – $300 |
| Heat Exchanger Descaling | $200 – $350 |
| Control Board Replacement | $300 – $600 |
| Gas-Line or Venting Repair | $250 – $500+ |
When repair costs exceed 50–60% of a new unit’s price or if your heater is over 15 years old, consider a full replacement.
Preventive Maintenance to Extend Lifespan
Regular upkeep is the best way to cut down on repair calls.
Start with an annual professional flush and descaling. In hard-water areas, a bi-annual service stops mineral buildup before it clogs your heater.
Next, install a pre-filter or water softener. This cuts down on sediment and protects internal parts.
Finally, check inlet filters and screens every month. A quick clean-out keeps water flowing at full pressure.
You’ll enjoy steady hot water and lower energy bills. Plus, regular service extends your heater’s lifespan.
Stay ahead of problems and keep your system running like new.
Choosing the Right Repair Service
Look for:
- Licenses & Certifications – Ensure technicians are EPA-certified and factory-trained.
- Transparent Warranties & Financing Options – Avoid surprise fees with clear service agreements.
- 24/7 Emergency Service – Tankless systems can fail at any time. Choose a company offering round-the-clock support.
- Local Homeowner Reviews – Check testimonials on Google or check our plumbing checklist.
Our A+ rating and decades of local experience guarantee quality and trustworthiness.
Conclusion
Tankless water heater repair isn’t something to put off. Early detection of electrical problems, unusual noises, or water pressure drops keeps your hot water flowing reliably.
For professional diagnostic inspections or preventive maintenance, post your plumbing issue!
Let our certified technicians restore your hot water system and help you avoid unexpected cold showers.
Ready to schedule your tankless heater service? 📞 Call us now or book online at: +1 (929) 944-2988
FAQs
Can I fix my tankless heater if it keeps shutting off?
Persistent shutdowns often indicate overheating due to scale buildup or venting issues. Try flushing first, but call a pro if it continues.
How often should I schedule professional maintenance?
For most U.S. homes, an annual flush and inspection suffice. Hard-water areas may need service every six months to prevent mineral buildup.
What causes a tankless heater to release water?
Water release can stem from a faulty pressure relief valve or thermal expansion. If you notice any leaks, have a licensed plumber inspect the unit right away.
