What is the most common problems with tankless water heaters?

By Robert Flores / October 26, 2022

Here are six of the most common problems and maintenance concerns for tankless water heaters: Mineral Buildup. System Overload. Cold Water Sandwich. Air Supply or Exhaust Blockage. Ignition Failure. Flame Failure. Mar 9, 2022

How long does it take for a tankless water heater to heat up?

Instant Hot Water Tankless units take about 15 seconds to bring water up to temperature, but you still have to wait for that hot water to arrive at your shower head or faucet, just as you do with a tank-type heater.

Do tankless water heaters get hot enough?

Tankless water heaters can get the water plenty hot enough. Depending on the brand and model, most tankless water heaters have a temperature setting that is adjustable between 100° to 140° (most tank water heaters are set around 120°).

How much gas pressure does a tankless water heater need?

However, the following conditions must be met: The minimum static gas pressure must be 8 in. w.c. or greater; The calculated dropped pressure (the static pressure minus the 3.0 in. pressure drop), must be greater than the highest minimum gas pressure required by any of the gas appliances on the system.

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What type of piping is used for tankless water heater?

Chlorinated Polyvinyl Chloride Use of CPVC Piping Systems with Tankless Heaters This PPFA User Bulletin is designed to provide general guidance for using Chlorinated Polyvinyl Chloride (CPVC) piping systems with residential tankless (instantaneous) water heaters. Specific situations may and often do require special precautions or procedures.

What happens if gas line is too small?

An undersized gas system can cause poor performance in the appliances. It could cause the burners to soot, pilots lights and burners to go out, or cause condensate to form in the heat exchanger of the furnace or water heater.

Do all tankless water heaters require gas?

The 3 most common fuel sources for tankless water heaters are electricity, natural gas and propane. An electric tankless water heater is designed completely different than gas models. However, a gas unit is designed to burn either natural gas OR propane.

How close can a gas regulator be to a tankless water heater?

You can use a 1/2 in regulator down to 7″ up to about 15 feet before the tankless. Mar 8, 2019

Can a tankless water heater be installed on outside wall?

A tankless water heater can be installed outside if it’s designed to withstand harsh weather patterns. There are specific models designed for indoor and outdoor usage, so you have to choose the correct type.

Do tankless water heaters increase electric bill?

Tankless heaters can be 8-14% more energy-efficient for households that use around 86 gallons daily. Installing a tankless heater at each hot water outlet, Energy.gov says, can increase tankless water heater energy savings by up to 27-50%. Oct 6, 2016

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Can you take two showers at once with tankless water heater?

Depending on the flow rate of your water heater, you may be able to take a shower and use hot water at the kitchen sink at the same time, but you probably won’t be able to run two showers and the kitchen sink. You could, of course, install two tankless heaters to provide you with a greater output of hot water. Jan 29, 2018

How long do tankless water heaters last?

Some people hesitate to decide on a tankless water heater because they can be a slightly higher cost; however, you get significantly more life out of one. A standard water heater tank lasts about 8-12 years. A tankless water heater can last as long as 25 years!

Why does my shower get cold with a tankless water heater?

Low Water Pressure Low water pressure is one of the most significant reasons why the tankless water heater suddenly cold during the shower. The flow within your device is lower than the activation flow rate required, resulting in the closing down of the gas burner or it may not ignite the burner at all. Jun 22, 2022

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

With a tankless water heater, you can take a shower, use the dishwasher, and do laundry all at the same time without losing hot water. On top of saving, you from the dreaded cold shower, it can also save you money and energy.

Can a tankless hot water heater fill a bathtub?

Yes, usually. A tankless water heater can provide hot water indefinitely, which means it will fill up the tub. However, you still need to consider how fast the heater can provide the temperature of water you want. Faucets work by mixing in hot water with the cold. Feb 22, 2022

How much does it cost to install a tankless water heater?

The typical range for tankless heater installation is between $4,500 and $6,500, averaging out to around $5,500 (including the water heater, warranty and tune ups). The tankless heater installation without the unit can cost between $1800 and $3500, averaging out to around $2650. Aug 26, 2022

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Can you drink hot water from tankless water heater?

“Hot water corrodes pipe metal and could become unsafe to drink.” When hot water runs through your pipes, it corrodes the metal and could become unsafe to drink. Even homes with “lead-free” plumbing aren’t safe, as they might still contain trace amounts of lead according to the U.S. Environmental Protection Agency.

Is an electric tankless water heater worth it?

For many people, the long-term benefits of tankless heaters more than compensate for their initial expense. A tankless heater can be up to 34% more efficient than a traditional water heater. This increase in efficiency can amount to annual savings of over $100, depending on the type and size of the heater. Jun 10, 2022

Can you put a tankless water heater inline with a tank water heater?

Takagi Tankless Water Heaters can be used as an indirect water heater in conjunction with a storage tank for high volume situations.

Can you put two tankless water heaters together?

It is possible to connect two tankless heaters to run parallel to each other, providing a larger amount of hot water on-demand. You could also get a larger tankless unit that can provide a higher flow rate.

Resources

https://www.eccotemp.com/blog/6-common-tankless-water-heater-problems-and-how-to-solve-them/index.php
https://www.thisoldhouse.com/plumbing/21019184/read-this-before-you-buy-a-tankless-water-heater
https://todayshomeowner.com/is-water-from-a-tankless-hot-water-heater-hot-enough/
https://cdn.globalimageserver.com/FetchDocument.aspx?ID=B01B2F08-B997-4C0E-9FEC-D666DEF226AC
https://www.ppfahome.org/page/UB18
http://users.snowcrest.net/thriftysupply/pdf/RTG-Gas_Piping_Facts.pdf

Gas vs. Electric Tankless Water Heater: Which is Best?


https://diy.stackexchange.com/questions/159323/will-a-2-psi-natural-gas-line-be-sufficient-for-a-tankless-water-heater

Can a Tankless Water Heater Be Installed Outside?

Tankless vs. Traditional Water Heaters | Which is More Energy Efficient?


https://www.erniesplumbingandsewer.com/never-take-another-cold-shower-get-a-tankless-water-heater

The Pros and Cons of a Tankless Water Heater


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https://www.mrplumberatlanta.com/help-guides/never-run-hot-water-tankless-water-heater

Can a Tankless Water Heater Fill an Oversized Bathtub?

Tankless Water Heater Installation Cost (2024)


https://www.eemax.com/2016/11/3-ways-tankless-heaters-will-change-how-you-use-water-2/
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About the author

Robert Flores