Generally as a water heater ages and nears the end of it's useful life, it will produce less and less hot water. 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.
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.
Sediment Is Affecting the Heating Element
The resulting sediment can reduce the lower heating element's effectiveness, causing only lukewarm to flow from your hot water tap. To fix this problem, make sure your hot water tank is flushed annually to remove any minerals.
Buildup throughout the water supply commonly causes low hot and cold water pressure. Sediment or mineral buildup happens in pipes or water tanks when hard water deposits minerals or sediments over time. Sediment and mineral deposits build up and damage plumbing lines by creating blockages or corroding metal.
The two options to fix this problem is to either have your plumber clean the water supply lines or replace them with new water pipes. Sediment and scale buildup inside the water heater. If your water heater is not that old, you could have your plumber flush and clean the sediment and scale from inside the tank.
Average Lifespan Of A Hot Water Heater
With regular inspection, draining, and flushing, you can expect a gas water heater to last anywhere from 8-12 years and an electric water heater to last anywhere from 10-15 years.
Over time, sediment builds up at the bottom of the tank. When the water is heated, the sediments harden. As a result, you can hear banging or rumbling noises from inside the heater. This is a sign that you need to get a new hot water heater, as its nearing the end of its operational lifespan.
First, check all your fixtures throughout the house to see if your cold water shower is a singular problem or a whole-house situation. If none of the plumbing allows hot water to pass, then the problem is your water heater. Check the temperature control on the unit to see if the setting is ideal.
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.
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 Department of Energy and water heater manufacturers have different opinions. 120 degrees Fahrenheit is the safety recommendation against scalding, but 140° is the common default setting.
Find the access panel for the thermostat(s) and use a screwdriver to remove the panel. Peel back the insulation. Use a flathead screwdriver to adjust the thermostat up or down. If your water heater has two thermostats, adjust both the same amount.
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.
Turn up the thermostat on the hot water heater. One of the easiest ways to make a hot shower last longer is by using less hot water while it's at a higher temperature. To do this, turn up the temperature on the thermostat that's attached to the hot water heater tank. (Not the thermostat on the wall.)
If temperature issues are more recent, it might be because a dip tube broke. To see if this is the case, you can look for small bits of plastic that might be found in your shower head, drain strainers, or appliance filter screens. If you do find plastic bits, your water heater's dip tube is probably damaged.
If you're only getting ice-cold water from your faucets, showers and sinks, there could be a few causes. Likely, the heating elements inside your water heater are broken or not working properly—or, potentially, your thermostat is incorrectly set.
Are you running out of hot water quicker than you used to? That's usually caused by a bad dip tube. But, if you have an electric water heater, the culprit could also be broken heating elements or a faulty thermostat.
Place a one-meter probe on the bottom left terminal. Place the other meter probe on terminal screw #1 just above the #2 terminal. You should get a reading of 0. The thermostat is faulty if you don't get a reading at all.
A water heater should deliver 70% of its rated capacity, with less than 30 degrees drop in water temperature. This is based on a 3 gallon per minute (GPM) flow rate, which simulates a typical residential application with a standard shower head and one additional kitchen or lavatory sink being used simultaneously.
CDC recommends your water heater temperature be set at 120 degrees Fahrenheit. OSHA has a different hot water temperature recommendation. OSHA recommends you keep your water heater at 140 degrees Fahrenheit so your risk of being exposed to microorganisms and Legionella is reduced.