How to Keep Your Tank and Tankless Water Heaters Running at Peak Performance

A Maintenance Guide to Extend Lifespan, Improve Efficiency, and Avoid Costly Repairs 

Why Regular Maintenance Matters for Both Tank and Tankless Water Heaters 

The performance, safety, efficiency, and longevity of water heaters depend heavily on proper upkeep. Skipping maintenance can increase the risk of breakdowns, energy waste, and premature replacement. Tank water heaters can have sediment buildup at the bottom of the tank, which often leads to corrosion, leaks, or system failure. Tankless water heaters can have mineral deposits form inside the heat exchanger, restricting water flow and forcing the unit to work harder. Whether you have a traditional storage tank or a tankless model, both systems need attention to operate at their best. 

See also: Your Water Heater Needs Maintenance Just Like Your Car 

What Maintenance Does a Tankless Water Heater Need, and How Often? 

Tankless water heaters provide endless hot water and impressive energy efficiency, but only when their internal components stay clean and free of buildup. Rheem recommends that these key maintenance tasks be performed at least once a year, often by a professional, to keep your unit in top shape. 

1. Clean the water filter. 

The small inlet filter prevents debris from entering the system. Remove and rinse it under running water to ensure proper flow in your water heater and prevent clogs that reduce performance or trigger error codes. 

2. Flush the heat exchanger. 

Mineral scale can build up inside the heat exchanger, reducing heating efficiency and increasing wear. A vinegar or descaling solution flush helps dissolve deposits and keeps the unit running smoothly. 

3. Inspect burners, flame sensors, and igniters. 

Have a qualified technician check for soot buildup, proper ignition, and any signs of corrosion or wear. 

4. Test the pressure relief valve. 

This is a safety device that releases excess pressure from the system. Make sure it opens and closes properly to prevent leaks and other potential damage. 

5. Check the condensate neutralizer. 

If your unit is a condensing model, inspect the neutralizer, media, and housing. Replace or refill the media if it’s saturated or worn. This will ensure that acidic condensate is properly treated before draining. Neutralizing the acidic condensate is important not only for preserving your plumbing system, but also for following environmental guidelines. 

6. Inspect vent terminations. 

Ensure the intake and exhaust vents are clear of dirt, debris, snow, or pests. Proper airflow is critical for safe combustion and efficient operation. 

Regularly performing or scheduling these maintenance steps helps prevent unexpected shutdowns and extends the lifespan of your tankless water heater. Some maintenance tasks, like cleaning the water filter, checking vent terminations, and visually inspecting components, can be handled by most homeowners with basic tools and care. However, tasks involving gas lines, burners, or electrical components (such as flushing the heat exchanger or inspecting sensors and igniters) are best left to a licensed professional. Check out our previous blog post for more on the importance of tankless water heater maintenance and building a relationship with your plumber.  

See tankless water heater blog. 

What Maintenance Does a Traditional Tank Water Heater Need, and How Often? 

Traditional tank-style water heaters benefit greatly from regular attention to keep them efficient, safe, and long-lasting. Here’s what should be done, typically on an annual basis. 

1. Flush the tank to remove sediment.
Over time, minerals and debris collect at the bottom of the tank, often reducing efficiency and causing rumbling noises. Draining a few gallons or performing a full flush helps prevent corrosion and improves heating performance. 

2. Remove, inspect, and clean combustion chamber and burner.
Inspecting the combustion chamber is the fastest way to determine if the burner is getting a proper air and gas mixture to allow proper combustion. A dirty combustion chamber can lead to the creation of carbon monoxide. 

3. Inspect the anode rod and replace it if needed.
The anode rod attracts corrosion to protect the tank’s interior lining. If it’s worn or mostly coated with calcium, it’s time for a replacement. Checking it annually can add years to your water heater’s lifespan. 

4. Test and flush the temperature and pressure (T&P) release valve.
Lift the valve’s handle briefly to make sure water flows freely through the discharge pipe. If it doesn’t release properly or if it continues to leak afterward, replace it to maintain safe pressure levels inside the tank. 

5. Check for leaks around the tank, fittings, and plumbing.
Inspect connections at the top and base of the tank, as well as any nearby piping. Catching small leaks early on can prevent water damage and costly repairs down the road. 

6. Insulate the tank and hot water pipes.
Adding insulation reduces standby heat loss and improves energy efficiency. Use pre-cut pipe sleeves or a water heater blanket rated for your model. NOTE: For gas water heaters, it’s important to leave the burner access and air intake areas uncovered for proper ventilation. 

7. Use a lighter or match to conduct a draw test at the draft hood to ensure proper venting.
By checking the draft of the flue you can determine if the carbon dioxide is traveling outside the home as it should be or escaping within the home.  

8. Check the tank’s temperature setting.
Ensure that the thermostat is set between 120°F and 125°F. This range provides comfortable hot water, minimizes scalding risk, and helps control energy use. 

Homeowners can safely handle most of these steps, like flushing the tank, checking for leaks, insulating pipes, and adjusting the temperature. However, inspecting or replacing the anode rod and T&P valve often requires tools and safety precautions best handled by a qualified plumber. 

See our previous blog post on tank water heater maintenance. 

See pages 22-25 in the Use & Care Manual for Electric Residential Water Heaters. 

How Water Quality & Usage Impact Maintenance Frequency 

Not all water heaters operate under the same conditions. The factors listed below can affect how often maintenance is needed, and understanding their influence helps you tailor your upkeep schedule to prevent premature wear. 

Hard water = more frequent descaling or flushing 

Mineral-rich water, or “hard” water, leaves behind calcium and magnesium deposits inside tanks and heat exchangers. These deposits reduce efficiency and can cause overheating or damage. In hard-water areas, plan to flush or descale about every six months. 

High-demand households = more frequent inspections 

Homes with multiple showers, large families, or heavy appliance use put extra strain on water heaters. More frequent system checks, such as every six to nine months, help catch early signs of wear, such as fluctuating water temperature or reduced flow. 

Sediment or mineral-heavy water = more filter maintenance 

If your water supply carries visible sediment or mineral particles, clean or replace your inlet filters more often. This simple step protects internal components and helps the system have more consistent water pressure. 

Environmental factors matter, too 

Installation location and water temperature can influence maintenance needs. Outdoor units face exposure to dust, insects, and weather, so vent inspections and cleaning may be needed more often. Cold inlet water (common in northern climates) increases heater workload, which can also shorten service intervals. 

Signs That Indicate the Need for Urgent Maintenance 

Recognizing early warning signs can help you avoid major breakdowns, water damage, or costly repairs. Acting quickly when these symptoms appear can also prevent safety hazards and protect your warranty coverage. 

Reduced hot water output or slower heating 

If your tankless unit struggles to deliver consistent hot water, or if your tank model takes longer to reheat, sediment buildup or scaling may be restricting heat transfer or water flow. 

Fluctuating water temperature 

Sudden shifts between hot and cold water often signal mineral buildup in the heat exchanger, a faulty thermostat, or flow sensor issues, all of which can worsen without timely maintenance. 

Unusual noises from the unit 

Popping, rumbling, or cracking sounds (especially in tank models) usually indicate sediment accumulation at the bottom of the tank. Ignoring these noises can lead to overheating or tank damage. 

Discolored water or visible mineral debris 

Rust-tinted or cloudy water points to corrosion or high mineral content inside the tank or pipes. Flushing the system and inspecting the anode rod can prevent more serious damage. 

Leaks or moisture around the base or fittings 

Even a small amount of standing water or dripping connections should be addressed immediately. Minor leaks can quickly lead to corrosion, electrical hazards, or tank failure. 

Foul smells  

A sulfur or “rotten egg” odor may mean bacterial growth inside the tank between the water and magnesium anode rod. This can be solved by switching to an aluminum anode or powered anode. 

Visible corrosion 

Corrosion on fittings or vents suggests deteriorating parts that need prompt repair or replacement. 

While minor issues like noise or mild discoloration can sometimes be resolved with a flush or cleaning, any leaks, odors, or inconsistent heating performance should be inspected by a licensed technician right away. Paying attention to these signs prevents small maintenance issues from becoming expensive system replacements. 

See our previous article, 7 Signs You Need to Call a Plumber 

Quick Tips for Proper Settings, Insulation, and Energy Saving Between Maintenance Visits 

Between professional maintenance visits, a few simple habits can help keep your water heater efficient and reliable year-round. 

1. Insulate exposed hot water pipes.
Pipe insulation reduces heat loss as water travels through your plumbing, helping hot water reach fixtures faster and cutting standby energy waste.

2. For tankless models:
Keep inlet filters clean, flush the system when needed, and ensure vent openings remain clear for proper airflow and combustion.

3. For tank models:
Use an insulating blanket or jacket (if compatible) to reduce heat loss, maintain proper clearance around the unit, and avoid setting the temperature too high.

4. Watch your energy bills.
A sudden spike in energy use without changes in household demand can indicate scale buildup or declining system efficiency.

See “Spring Cleaning for Your Water Heater” 

Conclusion: Consistent Maintenance Pays Off 

Regular care makes the difference between a water heater that fails early and one that lasts well past the warranty, all while saving energy and money. Following maintenance checklists, recognizing warning signs, and doing small preventive tasks yourself add up to real value.  

FAQ 

Q: How often should I flush my tankless water heater?
A: About once a year. If your water is hard or high in minerals, flush it more often. 

Q: When’s the best time for maintenance?
A: Spring or fall is usually ideal, since water usage is often moderate and temperatures aren’t extreme. 

Q: What’s the ideal water temperature setting?
A: Around 120–125°F for a good balance of comfort, safety, and efficiency. 

Q: How do I know if the anode rod needs replacing?
A: Check it yearly. Replace if it’s corroded, thinned, or coated with calcium or sediment. 

Q: Will DIY maintenance void my warranty?
A: Possibly. Check your manual, as some work must be done by a licensed technician to keep your warranty valid.