How Long Will it Take my 50 Gallon Water Heater to Heat Up?

Getting hot water out from a large tank based heater can be tiresome and may take up a lot of time. If you are staying in extreme weather conditions, heating the entire unit of 50 gallons may take up a long time. However, these mostly depend on a certain number of factors. The heating element is one of the most important components of the heater that affects how long it will take to heat 50 gallons of water. But it does not end here at all. Multiple other factors play their roles to determine how long it will take. Some of them are energy ratings and energy efficiency. But if you want to know more, this guide will help you.  You should also consider options like a Tankless Electric Water Heater as well.

Draw Efficiency

The drawing efficiency refers to the amount of water that needs to be heated to raise the temperature of the entire tank. The heater will not heat an entire 50 gallons of cold water. It has a certain draw efficiency calculation that will work together to raise the temperature. If you consider any decent heater, it must have at least 70% draw efficiency. It is important because the cold water comes in as the hot water flows out of the heater. It is calculated as 70 per cent of the overall storage tank.

First Hour Rating

The first-hour rating is the calculation that determines the amount of water flowing out of the heater during one hour of work. To calculate this amount, the heater will be required to set at a default temperature range which is usually 135 degrees Fahrenheit. The amount of water flowing out of the unit is recorded as the first-hour rating. Any heater with a decent first-hour rating can be considered as a top purchase. The test is however conducted with at least 3 gallons of water and it goes on running till the time the temperature drops by 25 degrees. Having a high FHR means that it is capable of delivering you sufficient quantity during the peak hour times.

Recovery Rating

The recovery rating is another important factor that determines the efficiency of the product. The recovery rating usually refers to the amount of power the unit requires to heat the water inside. There is always a huge difference in the temperature setting of the unit and the actual temperature the water inside the tank is receiving. This is the reason why it is better to have an efficient recovery rate that will reduce the time. To get the best results, you can opt for gas-based heaters rather than the electric-based heaters. Overall, they can warm at half the time of the electric heater.

Electric Hot Water Recovery

Any 50 gallons of water heater will usually consume around 5500 watts to heat the entire unit. When you set the temperatures at 120 Fahrenheit, it should take about 1 hour and 20 minutes to complete the entire heating time. However, you must make a note that this is applicable when the water entering the unit is at 60 degrees. When it comes in at 70 degrees, it should take about 1 hour to complete heating. On the other hand, when the inlet temperature is around 40 degrees, the time taken by the same unit to fill up an entire 50 gallons will be around 1 hour 50 minutes.

Gas Hot Water Heater Recovery

The efficiency of a gas water heater is far better than that of the electrical unit. This is mainly because it has a higher recovery rating. If you compare it with electric-based models, the recovery rate of the gas-based heaters is just half of the electric-based heaters. To be fair, it should take around 55 minutes to heat an entire 50 gallon when the water temperatures are around 40 degrees Fahrenheit. When the water temperature is around 60 degrees, the time required to heat the unit will be around 40 minutes. However, when the temperature is higher, it should take around 30 minutes.

Frequently Asked Questions

1. How long do water heaters last?

Usually, the manufacturers are very clear on making the internal components to be durable in a task-based model. The only places to worry are the tank and the pipes. If you have hard water in your locality and it is causing troubles, the entire unit should last about 5 years if you do not maintain it. However, if you do, it should last about 13 to 20 years or even more according to the quality of water and the maintenance.

2. Can a water heater explode?

Of course, accidents may happen in any situation. That’s the reason why you need to consider the safety valves of the heater while purchasing. When the heater is set at an excessively high temperature, it may explode. Having a temperature and pressure release valve may help you to avoid such situations. However, the chances of such situations arising are very slim for most of the models.

3. Should I turn off my water heater if it is leaking?

You simply can let your house catch fire if the heater starts leaking. Of course, the first thing that you must do is to turn off the heater completely. It must have a dedicated shut-off valve to turn down the operations of the heater. If you are not a professional, you need to call one or else, bring down the heater to a safe position and drain out the water inside and let it cool down. For more information you can read this article.


If you’re having a 50-gallon water heater tank, it has to take up time to start delivering you hot water. Composing of these factors, you can get to know about how much time it takes to heat the entire unit. So if you stay under extreme weather conditions, you must have a thorough look at these factors and get to purchase one. Do let us know about how long it took to heat your 50-gallon water heater.