Has your water heater reached the end of its life and needs to be replaced? Whenever this time comes, you should think carefully about which type and model of water heater you want to install. Installing another traditional water heater is always going to be the cheapest and easiest route to go. Nonetheless, installing a tankless water heater instead can definitely be worth the added cost.
How a Tankless Water Heater Provides Hot Water on Demand
The main thing to note about tankless water heaters is that they work on demand and only turn on when you start running hot water somewhere in the house. All of the pipes that make up your hot water system are connected and branch off from the main hot water outlet pipe on the water heater. The pipes also always remain full of water.
Once you turn on a shower or faucet, it results in water flowing into the water heater through the cold water inlet pipe. This triggers the water heater to turn on and begin heating. The unit will then continue heating until you shut the shower or faucet off and water stops flowing in through the cold water inlet.
It doesn’t matter if you only leave the hot water running for a few seconds or the entire day; the water heater will continue running as long as necessary. This is one of the main advantages of a tankless water heater: it ensures you have unlimited hot water.
How Tankless Water Heater Heat Exchangers Work
A tankless water heater uses a component known as a heat exchanger to continually transfer heat to water as it flows through the unit. When the unit is running, the electric heating elements or gas burner cause the heat exchanger to get hot. The heat then flows out of the exchanger into the water moving through the unit. Gas and electric units each have a different type of heat exchanger.
In a gas unit, the heat exchanger is basically just a large metal exhaust pipe that extends from the burners to the top of the unit where it connects to the flue or vent pipe. As the burners produce hot combustion fumes, the fumes rise through this pipe and quickly heat the metal. When the unit turns on, water begins flowing through a copper pipe that is coiled around the heat exchanger. The heat from the exchanger quickly heats the copper pipe and then heats the water as it moves up through the pipe.
Electric units have a multi-chambered heat exchanger that consists of several interconnected pieces of copper pipe. Each chamber has an electric heating element at the top that continually transfers heat to the copper. As the water flows up or down through each of the chambers, the water heats up until it reaches the correct temperature.
All tankless water heaters also have thermometers and components known as thermistors that allow them to control the amount of heat they produce. This feature ensures that the water is always warmed to the correct temperature. The cold water coming into the unit first passes through the inlet thermistor. This thermistor tells the unit just how cold the water is, allowing it to accurately determine how much heat it needs to produce.
The hot water also passes through a second thermistor before exiting the unit, which lets the unit know if the water is the right temperature or if it needs to increase or decrease the amount of heat it’s producing. There are also additional thermometers that continually measure the temperature of the heat exchanger to ensure it isn’t too hot or too cold. In an electric unit, each heat exchanger chamber has a thermostat.
Benefits of Installing a Tankless Water Heater
Tankless water heaters provide some other benefits in addition to ensuring you never run out of hot water. One is that they’re highly efficient and typically use less energy than traditional water heaters. In some cases, a tankless water heater can reduce how much energy you use for water heating by over 30%. However, the amount you’ll save depends on how much hot water your household uses.
Another great feature about tankless water heaters is that they last a long time and require very little maintenance. You’ll rarely get more than 12-15 years of life out of a traditional water heater, whereas most tankless units have a lifespan of 20 years or more. The biggest issue with traditional units is that the tank almost always starts leaking at some point. When this happens, you then have no option but to replace the unit.
Downsides to Having a Tankless Water Heater
While tankless water heaters have some significant advantages over traditional units, they have a few downsides as well. For most people, the advantages definitely outweigh the drawbacks. However, this isn’t always going to be the case, so it’s important that you consider both the pros and cons when trying to decide if a tankless water heater is right for you.
The main downside is the increased lag time you get with a tankless unit. Lag time refers to how long it takes for the water to be fully hot after you turn it on. With a traditional unit, the lag time is usually fairly short since the water that flows out of the tank is already hot. That means you just need to wait for however long it takes for the hot water flowing out of the tank to reach whatever fixture you’re using.
That said, you’ll often have a slightly longer lag time in winter because your cold pipes may initially absorb some of the heat, causing the hot water to be slightly cooler at first.
The reason tankless water heaters have a longer lag time is that it takes a bit of time from when the unit first turns on until the heat exchanger warms up. With a whole-home unit, you can usually expect the lag times to be anywhere from 30 seconds to 2-3 minutes. It really depends on how far away the fixture is from the water heater and how cold the incoming water is.
The longer lag times also mean that your water bills will often be slightly higher with a tankless unit. However, the difference usually isn’t that substantial, unless you have a much larger household or people who shower multiple times a day.
If you need a new water heater or any other plumbing services in the Lincoln or Omaha areas, John Henry's Plumbing, Heating, Air, and Electrical is the company to look to. We’ve been in business since 1996 and have an outstanding reputation for performing quality work and providing top-notch customer service. We carry a selection of efficient tankless and traditional water heaters from trusted brands and will happily guide you through all of your available options. You can also rest assured you’ll get a fair deal thanks to our free estimates and honest, upfront pricing.
To get help choosing the right replacement water heater for your home, contact us today.
