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How Long For Water Heater to Heat Up?

Jennifer Hansen
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by Jennifer Hansen

Who doesn’t love a long, hot shower after a hard day?

You’ve probably come home one day looking forward to one, only to find that a family member is in the shower or they’ve started the dishwasher or washing machine, using up all that hot water.

Fortunately, it doesn’t take a modern hot water tank long to replenish its supply. In this short article, we’ll teach you everything you need to know about water heaters and how they serve your home.

How Long Does It Take a Water Heater to Heat Up?

How long does a water heater take to heat up in practice? The actual number will be a combination of several factors. However, as a general guide, you can expect the following:

  • Gas-powered water heaters: 40 minutes to an hour
  • Electric and solar-powered water heaters: 1-2 hours
  • Heat pump water heaters: 1-1.5 hours
  • Tankless water heaters: Less than one minute

As a homeowner, your job will be to determine your hot water usage during peak times. For example, if you and your partner get home at the same time, shower at the same time, and also tend to run the washing machine and dishwasher all at once, then your hot water tank needs to handle all of that. If you tend to stagger your water-related tasks, you can get by with a smaller, slower water heater.

You should be able to find your appliances’ hot water requirements by looking through the documentation that came with them. However, calculating your shower usage is a bit more complicated.

First, you need to find out what temperature you prefer to take your showers and figure out how much water you use. For example, if your shower head puts out a flow of two gallons per minute and you take 15-minute showers, you’re using about thirty gallons of hot water. The higher the temperature you shower at, the greater the demand you place on your water heater.

To figure out your maximum demand, just add everything together. If your water heater can produce hot enough water faster than you use it, you’re golden!

Hot Water Tanks: Types and Time Required

There are many types of hot water tanks on the market today, so answering the question of “how long does it take a water heater to heat up” isn’t always straightforward. How long for a water heater to heat up depends on several different factors.

Water Heater Size

Water heater size is the first thing to consider when your water heater is doing its job. Like with a pot of water, the more water you want to heat, the longer it will take to reach your desired temperature. Tankless water heaters are different because they don’t use water tanks at all; they can offer a limitless supply of hot water because they heat water on demand.

Energy Source

The next most important thing to consider is what your heater uses for energy. Generally, gas-powered water heaters, regardless of whether they use propane or natural gas, operate much faster than electric water heaters. This is because gas burners can reach higher temperatures (and they can reach those temperatures faster) than an electrical heat source.

Today, electric water heaters are also available in hybrid models (also known as heat pump water heaters). These water heaters provide a nice midpoint between electric and gas-powered water heaters because they’re both fast and energy-efficient. Hybrid water heaters save energy by heating water more slowly when it’s not in-demand, then heating it quickly when you need it.

First Hour Rating

The First Hour rating on a water heater is critical, and it’s something that you should keep in mind when choosing a new water heater. Essentially, the higher the first hour rating, the more hot water your heater can deliver within the “first hour” of being run.

Incoming Water Temperature

The temperature of the water as it comes into your water tank makes an enormous difference, too. If water is sitting inside your home for a long time, it’ll eventually come to room temperature. However, if your system is pumping in freshwater from a well or a city pipeline, it may be significantly cooler.

How cold this water is depends on where you live. For example, if you live in Maine, the temperature of shallow groundwater can often be near-freezing. However, on the southern tip of Florida, groundwater is usually  upwards of room temperature already, even when it’s in the ground. As such, your water heater will have to work harder (and longer) in cold regions.

Problems and Solutions

What if your water heater isn’t performing to your expected standards? There can be many reasons why this might be happening, such as:

  • Your water heater is reaching the end of its life and needs replacing
  • Your heater is full of sediment build-up and needs to be flushed
  • A heating element or other small part of your water heater needs fixing or replacing
  • The pipes leading to or from your water heater are blocked or leaky
  • Your water heater was never big enough to handle the demand you place on it

Before kicking your water heater to the curb, it’s a good idea to have a professional come out and take a look at it. They may be able to identify a small issue that needs fixing, saving you quite a bit of money over replacing the entire water heater. However, if your water heater is old and inefficient, it may benefit you more to replace it anyway.

If you’re not ready to replace your water heater yet, there are still some things you can do (besides maintenance) to increase your hot water flow.

One great way to feel like you’re getting more hot water is to turn up the water heater’s temperature. It’s essential to this carefully, though, as turning it up too high can present a scalding hazard.

Another thing you can do is invest in low-flow appliances and fixtures. These will use less water than ordinary fixtures and appliances, meaning your hot water will stretch further than before.

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About Jennifer Hansen
Jennifer Hansen
Jennifer is a mother of 2 and has always been a careful shopper, determined to make the best buying decisions for her family. She loves researching the marketplace to find the right products for her household. She leads a small but mighty team of writers in bringing you WaterFilterSpot.
Jennifer Hansen
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