Guide on How Long a Water Heater Take to Heat Up

If you are like me and countless others, hot showers are some of the most beautiful life luxuries that could be hard to live without. A hot shower soothes like no other and removes the remnants of a long, hard day effectively.

Unfortunately, a faucet does not necessarily produce hot water on its own and most people’s water heaters, including mine, do not create an endless supply of hot water. That would be THE dream!

That said, hot waters can take some amount of time to turn water already far too cold to be enjoyable in the shower unless it is right in the middle of summer and the heat is palpable.

This means any homeowner should know how long to wait when their supply of hot water runs out. I could remember distinctively asking this question when I moved out to my own apartment, “How long will it take my water to heat up?” Looking back, it’s not such a dumb question, after all. I do not think people necessarily know this information right from the start unless they cared about such stuff when they were younger. Not me, certainly.

Here, I will be sharing what I learned about water heaters and how long for the hot water heater to heat up.

Determine Size and Capacity

Of course, not all water heaters are the same in make and capacity. How long does a new water heater take to heat up may not be similar to how long it would take an old water heater.

The size of the water heater can also affect the time it takes for water to heat up. The usual size of a water heater is 40 gallons, which is what I have at home, so that is my basis when sharing what I know of about how long for hot water heater to heat.

The rule of thumb based on what I read and heard is that the bigger the size of the water heater, the longer it can take to heat up the water. An impatient person such as me probably should not get more than 40 gallons, unless this is necessary.

Determine the Type of Water Heater

Technician servicing an hot water heaterNot all types of water heater work the same. To know how long for hot water heater to heat up water, it is crucial to know whether the heater is Gas, electric, solar, and tankless. Gas heaters can take at least 30 minutes to 40 minutes to heat the water in the tank fully.

For those with electric heaters, it can take twice as long for hot water heater to heat compared to using gas heaters. My parents’ home uses electric heaters, and from my experience, it takes at least an hour up to an hour and 20 minutes to heat water. While waiting for the water to heat up, I used to cook breakfast first for my parents. Once done, I will only need a few more minutes to wait before the hot water is ready and I can finally take a bath.

Based on what I know, solar heaters can take as much time as electric heaters to heat up water. They can take much longer than gas heaters so they are not necessary for those who cannot wait. Solar heaters are usually connected to an electric water heater, so it is not surprising to note that they can take a relatively similar amount of time to heat up the water.

I never liked solar heaters because the idea of not having any hot water if there is no backup energy source on a cloudy day does not appeal to me. It is during cloudy days that I am particularly keen on having hot baths in the first place.

If I can have my way, I would rather have a tankless heater. Theoretically, tankless heaters are designed to provide the home with an unlimited supply of hot water.

How long for hot water heater to heat up using tankless heater is next to no warmup time — wow! This could just be the dream water heater come true.

The problem is that it is relatively a new technology so I am sure it is going to cost an arm and a leg and it may not even be perfect. However, I am liking the idea of not ever having to wait anymore for the shower to heat up again, so I think I will really look into this more and probably save up.

Compute How Long Does a Water Heater Take to Heat Up Water; It’s Possible!

Since I am sharing how long for hot water heater to heat up based on my own experience and research only, it might not necessarily be accurate.

However, there was an article I recently read that provides the specific calculations one can make to know how long does a water heater take to heat up. I just love Physics and Mathematics that way, they do come handy once in a while.

According to Men’s Health, the equation involves finding out how long I want to shower and how much hot water is left at that time. Once I have these, I should deduct the minutes of hot water remaining from the expected shower duration, the difference of which I should multiply by 4.3 when I am using an electric heater, or just by 1.9 if I am using gas.

The magazine also asked me to determine the tank’s total available minutes of hot water and then deduct the number of minutes the last person used the hot water for.

A chart was provided, showing that 30 gallons in tank capacity mean 19 minutes of hot water in electric heaters and 30 minutes in gas water heaters. If the water heater is at 40 gallons’ tank capacity, this means 25 minutes of hot water in electric heaters and 40 minutes in gas heaters. Lastly, for water heaters with 50 gallons’ tank capacity, this means having a total of 31 minutes of hot water for electric heaters and 50 in gas heaters.

I tried this method on my parents’ home, where the electric heater capacity is at 30 gallons. When my dad took a hot shower for 15 minutes, I calculated that there would just be four minutes of hot water remaining – certainly not enough for me!

Since I also wanted to loll in my own hot shower for at least 15 minutes, my calculations showed that I needed to wait at least 47 minutes before stepping in. Given that this was nearly an hour, I took the time to eat some breakfast and brush my teeth. Once I got into the shower after 50 minutes, I got some hot water that was certainly relaxing, making me ready for the whole day.

Check for Sediment Buildup!

Technician servicing heating boiler

Sometimes though, I could notice that my water is taking too long to heat. Instead of the usual 30 minutes, I suddenly experienced plunging myself into a cold shower, because the water is not hot yet. I had my water heater checked and found out that sediment already has built up in my water heater tank.

The sediment is a mix of dissolved materials like calcium and magnesium that can go into the bottom of the tank and settle there. overtime, the buildup of sediment can displace the amount of hot water in the tank, which can lead to two things. First, it will make the water less available and two, it will take a longer time to heat between refills.

Based on my experience, therefore, finding out how long does a water heater take to heat up water is important also as it can indicate whether the water heater is still in mint condition.

It can signal whether the water heater should already be checked and the sediment buildup cleaned out.  In general, water heaters that are in use for a decade and more are already considered old and should be replaced for better performance. How long does a new water heater take to heat up? Certainly, faster than a decade-old one!

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