Two of the most important parts of water heaters to consider if you're running out of hot water frequently are the tank and the thermostat. The tank may be too small for your needs, or the thermostat may be set too low for your preferences.
If your hot water runs out too fast, you may have an issue with: Too much hot water demand from multiple sources at the same time. Sediment build up inside of your water heater tank. A broken dip tube.
The most common part that gets damaged is the “Dip Tube”. When it gets worn down, it leads to the mixing of cold and hot water. So, you feel as if the hot water runs out after 10 mins. The Solution – A damaged dip tube has to be replaced.
So, if you have a 40-gallon hot water tank, you should be able to get four average-length showers out of your hot water tank. This also depends on how much hot water you use for other things.
It could be faulty parts in the water heating unit, an obstructed flue, the build-up of sediment or a malfunctioning temperature control. When dealing with these problems it is always best to call in the plumbing professionals.
Burned-Out Elements. If the heating elements in an electric heater are old, burned-out or simply not large enough, they cannot heat all the water the tank holds. Sometimes the heating element loses its function because of sediment build-up.
The average adult uses about 10 gallons of water per shower (at a rate of 2 gallons of water per minute). If you assume that an 80-gallon tank has about 55 gallons of hot water to dispense before refilling, that means you have 27 or so minutes of total shower time before running out of hot water.
Your most basic calculation is dividing your water heater's capacity by your shower head flow rate. The low-flow gets you 26 minutes of hot water. The high flow gets you only 16.
If you have a low-flow showerhead installed, you can expect to use about two gallons of water per minute, equalling 20 gallons throughout a 10-minute shower. With a standard showerhead, around half a gallon more water will emerge each minute, so a 10-minute shower would use somewhere close to 25 gallons.
Sediment or Rust
Over time, especially if you have hard water, minerals in the water can gather at the bottom of the water heater near the burner. This sediment can prevent heat from the burner from reaching the water, compromising energy efficiency and your access to hot water.
Connect a hose to the drainage valve and make sure that you lead it out somewhere safely to drain, knowing this water will be very hot. Into a bucket or outside are your best course of action. Drain and then flush with the cold water valve open until the water runs clear of any sediment.
Most often this is caused by sediment building up inside the tank. Sediment build-up will decrease the amount of hot water your water heater can produce. Usually the water heater will be noisy or tend to make a loud rumbling sound if sediment is the problem.
Faulty or burned out heating elements is one of the main reasons why your hot water goes cold quickly. Old or burned out elements account for the reduction of hot water and will cause your hot water to go cold quickly or not have any hot water at all.
One sign of a failing dip tube is little white flecks of plastic in your hot water supply, and/or your water may not feel as hot as it used to. Dip tubes normally last as long as their water heaters, but some types of dip tubes can become brittle after spending a few years submerged in hot water.
In the average home, the water heater will run for about three hours each day. Total run time can range from one to two hours for new tankless water heaters to five or more hours for older tank style water heaters.
120 degrees Fahrenheit is the safety recommendation against scalding, but 140° is the common default setting. Most experts agree that anything below 120 degrees creates a risk for bacteria to develop inside your water heater from stagnant water, such as legionella that causes Legionnaire's disease.
The average gas heater takes between 30 and 40 minutes to fully heat up the water in its tank. The average electric heater takes about twice as long as the average gas heater to fully heat up the water in its tank, so you can expect it to take between an hour and an hour and 20 minutes to heat up.
If you limit your hot water activities to ONLY showers, a 40-gallon water heater could comfortably handle 2 average-length showers at the same time (17 + 17 = 34 gallons).
A 30 gallon water heater should be able to supply enough hot water to meet the needs of a household of 1 -2 people with only one bathroom. A good way of measuring your hot water requirements is calculate your peak hot water usage and compare it the first hour rating of a water heater.
With a low-flow showerhead, you can expect to use about two gallons of water each minute, equating to 10 gallons over a 5-minute period. If a standard showerhead is fit, the shower will likely emit around an extra half gallon of water per minute, so a 5-minute shower will use in the region of 12.5 gallons.
Electric Heater
Ideally speaking, an electric water heater takes around 60 to 80 minutes to release hot water with a tank capacity of 40-gallon. If the tank capacity is 80-gallon, the recovery time can be more than two hours.
Frequent hot showers and baths can lead to dry, itchy skin or even rashes. Cooler or lukewarm showers even just a few times a week can keep skin hydrated and help hair stay strong and shiny. If your skin appears red following your bath or shower, your water is too hot.