Yes, most manufacturers strongly recommend flushing your tankless water heater every 12 to 24 months to prevent mineral and sediment buildup (scaling). However, the exact frequency depends heavily on your local water quality and usage.
Flushing tankless water heaters whose heat exchangers are blocked by the lime scale is very important and must be done before something happens. If you don't flush the water heater, the heat exchanger can be damaged as not enough water will pass through and cool it down.
Check with a local pro for your specific job. Cost Insights: Tank water heater flushing costs $110 to $200, while tankless models run $150 to $250 due to their more complex components. Your tank size and household hot-water use affect flush time, since larger tanks take longer to drain and refill.
Plumbers often hesitate to recommend tankless water heaters because they act like high-performance sports cars. Unlike traditional tank models that are "workhorses" and can function while mostly ignored, tankless units require precise installation, regular maintenance, and are highly sensitive to mineral buildup.
Here are some common reasons why your tankless water heater might not be working and how you can troubleshoot these problems.
Tankless water heaters typically last 15 to 20 years—nearly double the lifespan of traditional tank models, which average 10 to 12 years. With rigorous maintenance, some high-quality units can perform reliably for up to 25 or even 30 years.
Cons: Minimal energy savings compared to well-insulated tank heaters, high energy demand (12 kW to 30 kW), potential need for electrical system upgrades, and higher operating costs for electric models.
For larger households, multiple showers, laundry, and dishwashing may run at the same time. Hot water demand could reach 10–12+ GPM. A high-capacity tankless water heater—or even two units installed in parallel—may be the best solution.
The answer is no — tankless water heaters can save money on your monthly electric bill because they're 8%-34% more efficient than storage water heaters.
Gas tankless water heaters installed by December 25, 2025, might qualify for a $600 federal tax credit. The government is offered this 30% credit through December 2025 to help cover the cost of the unit and its installation. This tax credit comes from the 25C Energy Efficient Home Improvement Tax Credit program.
Flushing your tankless water heater with standard food-grade white vinegar is the best way to remove scale buildup, improve energy efficiency, and extend the unit's lifespan. This annual maintenance takes about an hour using a few basic tools.
Flushing a tankless water heater typically takes 45 to 60 minutes. The entire maintenance process—including setup, circulating the descaling solution, rinsing the system with fresh water, and draining—usually takes about 1 to 1.5 hours from start to finish.
A 10-minute shower typically uses 20 to 25 gallons of hot water. Because showers are usually mixed with cold and hot water to reach a comfortable temperature, the actual volume of hot water drawn from your heater will usually be slightly less, while a low-flow showerhead can reduce this amount by up to 50%.
Use 4 gallons (15.1 liters) of undiluted white vinegar to clean your tankless water heater. Never use chemical solutions of any kind. Since your home's drinking and bathing water mostly likely flows through your tankless water heater, using chemical cleaning solutions could be extremely harmful to your health.
This problem usually comes down to capacity, heat production, or mixing issues inside your plumbing system. Sometimes the fix is simple, like adjusting your water heater temperature or flushing out sediment. Other times you may need a new mixing valve, an element replacement, or a different size water heater.
In most homes, Heating and Cooling (HVAC) systems drive the highest energy costs, accounting for nearly 40% to 50% of your total electricity bill. Following these, the appliances that run up your bill the most include water heaters, refrigerators, and laundry machines.
For a 3-bathroom home, you generally need a tankless water heater with a flow rate of 7 to 9 GPM (Gallons Per Minute). This size can effectively run 2 to 3 major hot water fixtures (such as a shower and a washing machine) simultaneously.
A tankless water heater usually goes cold mid-shower because the water flow drops below the heater's minimum activation threshold, or the system is overloaded by using too many fixtures at once. It can also happen if sediment blocks the filter or the unit is improperly sized.
Tankless water heater installation costs between $1,404 and $3,899 for your home, depending on unit size and setup. The fuel type you choose shapes your upfront and utility costs, with electric lower-priced and solar earning tax credits.
If a standard showerhead is fitted, it will use around an extra half a gallon each minute, accounting for a 25-gallon emittance every 10 minutes, or 50 gallons throughout a 20-minute shower. *1 gallon = 4.54 litres.
Plumbers often hesitate to recommend tankless water heaters because they act like high-performance sports cars. Unlike traditional tank models that are "workhorses" and can function while mostly ignored, tankless units require precise installation, regular maintenance, and are highly sensitive to mineral buildup.
Insulate your tankless water heater pipes to prevent freezing and bursts. When plumbing guides talk about “insulating your tankless”, they mean the pipes going to and from your unit. They're as susceptible to freezing and bursting as any other pipes in your plumbing system.
Plumbers generally recommend professional-grade water heaters sourced from supply houses rather than retail big-box stores, as they feature thicker, heavier-duty components. The most trusted brands among professionals depend on the type of system you need: