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. A water heater that is nearing the end of its lifespan.
The most likely reason for your showers running out of hot water too fast is that your water heater is too small for your home's demands. Standard water heaters come in different sizes based on their “first hour rating.” This rating describes how many gallons of hot water a unit can produce in one hour.
Sediment and corrosion build up within the tank. This lowers the water quality and slows the heating element's effects. A simple draining and cleaning process resolves these plumbing problems. A plumbing professional is able to complete this service quickly.
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 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.
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.
If you've had your shower for some time, there may be a build-up of limescale and sediment in the showerhead obstructing the flow of water. To clean it, unscrew the showerhead from the hose and immerse the whole thing in a bowl of vinegar for 8 hours. Then manually remove any remaining debris.
There are several reasons; the distance from the water heater, the diameter of the piping, and the flow rate of the water. The further the hot water has to flow, the longer it takes to heat up the shower faucet. This is especially true with a larger home.
Average Water Heater Recovery Times
60-70 minutes (for a gas tank water heater) 120 minutes (for an electric tank water heater)
Because there are all kinds of reasons why hot water in a house might be running out faster than normal: power supply problems, rusty pipes, a pilot light out, sediment, a broken dip tube—and that's just to name a few!
For instance, a typical shower uses about 10 gallons of hot water. 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.
Say your electric heater is 30 gallons. If the previous shower lasted 15 minutes, you're looking at about four minutes of hot water remaining. If you want to loll in your own 15-minute shower, you'll need to wait 47 minutes before stepping in.
If your shower is running out of hot water, it's likely due to one of the following problems: Malfunctioning thermostat. Broken dip tube. Sediment buildup in the tank.
The average American shower uses 17.2 gallons (65.1 liters) and lasts for 8.2 minutes at average flow rate of 2.1 gallons per minute (gpm) (7.9 lpm).
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.
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.
If a standard showerhead is fitted, it will use around an extra half a gallon each minute, accounting for a 25-gallon emittance every 10 minutes, or 50 gallons throughout a 20-minute shower. *1 gallon = 4.54 litres.
A standard showerhead uses 2.5 gallons a minute, or 25 gallons for 10 minutes. Either way, the shower saves water – as long as you don't go past 10 minutes. The shorter the shower, the greater the savings.
Low water pressure
If your shower goes cold after a few minutes, it might be that you've been unlucky enough to be showering just as the water pressure dropped. The best thing to do is see if other taps are experiencing lower pressure, plus check if your neighbours are experiencing a problem too.
If the thermostat on your hot water heater cannot read the temperature correctly, it will heat water to an incorrect temperature and result in you only getting lukewarm water. To test if the thermostat is broken, turn it to a higher temperature and see if the heater turns on.
If you place your water heater on a higher setting, the water coming out of it will be hotter, and you won't need as much to reach that same temperature. Raising the temperature setting on your water heater ultimately makes your hot water supply last longer.
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.
If the water is constantly lukewarm, it usually indicates a problem with the upper heating element. A short-lived supply of fully hot water points to a problem with the lower heating element.
Tip: The build up of sediment in the tank can reduce your water heater's energy efficiency and also clog your water lines. Avoid these problems and increase the life of your unit by flushing your water heater every six months.