What is the downside to an on demand water heater?

Author: Mrs. Violet Morissette  |  Last update: Wednesday, April 15, 2026

Tankless Water Heater Cons Limited Flow Rates: Reduced flow rates can lead to poor heating efficiency and low-temperature water. Before deciding on a tankless water heater, ask an experienced plumber about the appropriate flow rate for your home.

Why avoid a tankless water heater?

Additional Installation Costs

Tankless water heaters are much more complex than traditional hot water tanks. As a result, they require professional installation. If you're switching from a hot water tank to a tankless unit, you will likely need your gas lines rerouted, as well as a larger gas supply line.

What is negative about a tankless water heater?

Before you commit to buying a tankless water heater, the primary drawbacks to know include: Higher upfront costs. Tankless water heaters are, on average, quite a bit more expensive to buy and install than tank water heaters. Access to fuel.

What do plumbers think of tankless water heaters?

St Paul Pipeworks plumbers advise against purchasing tankless water heaters from big box stores or online retailers, as homeowners often lack the expertise to determine the correct sizing for their specific needs. Many negative reviews about tankless systems stem from improper sizing or piping installations.

Why don't more people use tankless water heaters?

  • Higher Initial Costs : Tankless systems typically have a higher upfront cost compared to traditional tank water heaters.
  • Installation Complexity : Installing a tankless system can be more complicated, which may require changes to gas lines or electrical systems.
  • Limited Flow Rat

3 Things They Don’t Tell You About Tankless

What is the downfall to a tankless water heater?

A tankless water heater cannot provide hot water faster than its ability to heat the water. While a tank unit can provide hot water for multiple uses at once, a tankless unit might not be able to support simultaneous usage, such as washing dishes, taking a shower and running a washing machine all at once.

Can you replace a 50 gallon water heater with a tankless water heater?

A 50-gallon water heater should be replaced with a tankless system with a 10 GPM flow rate just to be safe. Selecting the right flow rate ensures you won't experience cold showers or excessive energy costs. Proper sizing optimizes performance, providing hot water on demand without unnecessary waste.

Can I replace my 40 gallon water heater with a tankless water heater?

Absolutely! In fact, tankless water heaters are becoming the standard for new home construction because of the energy efficiency.

Is there an IRS tax credit for a tankless water heater?

The federal tax credit for tankless water heaters in 2024 is an excellent opportunity for homeowners to save money while investing in energy-efficient water heating solutions. This tax credit is effective from January 1, 2023, to December 31, 2032.

What water heaters do plumbers recommend?

AO Smith, State, and Bradford White are all very dependable brands and are known by professional plumbers for top-quality gas and electric water heaters. Master plumber Eddie Heil put it this way, “AO Smith, State, and Bradford White are all great choices in our experience.

Where should tankless water heater not be installed?

Keep your water heater away from outside elements

If your tankless heater is exposed to extremes weather conditions, it will run a greater risk of premature failure. So, make sure your appliance is away from doors and windows, and never installed in the garage or basement.

Can you take a long hot shower with a tankless water heater?

While a tankless water heater will deliver an unlimited stream of hot water, they struggle to deliver a lot of hot water at one time. So while you might be able to take 100 showers in a row if you have the dishwasher, washing machine, and shower going at the same time you might have problems.

Should I replace my water heater with a tankless?

Tankless water heaters can save you money on your energy bill in the long run, but they also require a greater initial financial investment upfront. Installation costs more, especially if you're installing your first tankless heater and require new gas lines and venting or a dedicated electrical circuit.

Is it worth converting to a tankless water heater?

Even for homes with high water usage, up to 85 gallons per day, tankless water heaters can offer up to 14% energy efficiency savings. However, while they offer energy savings, the higher upfront costs and installation expenses can result in a long payback period, ranging from 12 to 27 years.

What is the life expectancy of a tankless water heater?

One of the most common questions asked by consumers about tankless water heaters is how long they will last. A tankless water heater can last anywhere from 15 to 20 years with proper maintenance and operation. In comparison, a standard tank water heater normally has a working life of 10 years or less.

Why does the breaker keep popping on my tankless water heater?

If the circuit breaker in your tankless water heater tends to trip frequently, it may indicate that the circuit is overloaded or the circuit breaker is faulty. Overloading occurs when multiple high-power appliances draw excessive current from the same circuit, causing the circuit breaker to trip as a safety measure.

Can I write off a water heater on my taxes?

Water Heater Tax Credit Details.

You can claim 30% of the project cost, up to a $2,000 maximum credit. Heat pump water heaters that have earned the ENERGY STAR are eligible for this credit. You can find a list of ENERGY STAR certified models here.

Are tankless water heaters worth it?

Advantages and Disadvantages of Tankless Water Heaters

The initial cost of a tankless water heater is greater than that of a conventional storage water heater, but tankless water heaters will typically last longer and have lower operating and energy costs, which could offset their higher purchase price.

What is the new tax credit for 2024?

You may be eligible for a California Earned Income Tax Credit (CalEITC) up to $3,644 for tax year 2024 as a working family or individual earning up to $30,950 per year. You must claim the credit on the 2024 FTB 3514 form, California Earned Income Tax Credit, or if you e-file follow your software's instructions.

What is one disadvantage of a whole house tankless water heater?

As we discussed above, the biggest downside of owning a Tankless Water Heater is its higher cost. The initial installation costs and the price of the unit are more expensive than a traditional Storage Tank Water Heater. Another downside of a Tankless Water Heater is that it has limited hot water.

Who makes the best tankless water heater?

Top Tankless Water Heater Brands in 2025
  • Noritz.
  • Navien.
  • Rinnai.
  • Takagi.
  • Rheem.

Do you have to replumb your house for a tankless water heater?

Do I need to replace all my home's plumbing if I install a tankless water heater? Rarely is a complete overhaul necessary. However, you may need to upgrade certain sections of your plumbing, particularly those leading into and out of the tankless unit, to ensure proper water flow and volume.

What is the average labor cost to install a 50 gallon gas water heater?

In general, plumbers cost $45 to $200 per hour, while electricians cost $50 to $100 per hour. Expect the following average price ranges for labor alone: Replacing a tank-style water heater: $150–$450. Replacing a tankless water heater: $600–$1,850.

Do I need to upgrade my gas line for a tankless water heater?

The Tankless Truth is, in many cases, you don't need to upgrade your gas supply line when going tankless.

What maintenance does a tankless water heater need?

The most complicated and time-consuming tankless water heater maintenance is typically descaling and flushing out the unit. Even with the inline water filter, lime and calcium deposits can build up inside the tankless system. If you have hard water, it's a good idea to descale and flush the unit once a year.

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