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.
Hot water being in limited supply is totally normal. 5-10 minutes is a little quick, but not unheard of. I only get about that long, because the water pressure in my shower is insanely high. You get used to it.
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.
Water Heater Issues
If your water heater isn't working properly, several fairly common issues can lead to less hot water availability. A malfunctioning thermostat, broken dip tube, and sediment buildup are the most common repair issues that can explain why your shower quickly runs out of hot water.
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.
Sediment can be things such as sand, silt, or rust that take up space in your water tank. As a result, your hot water supply dwindles. However, another issue with sediment is that your heating elements heat the sediment instead of the water, so it is slower to heat.
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.
Yes, it's very bad to turn your water heater all the way up. To do so will reduce its life, increase your electricity bill and could possibly cause scalding—particularly if you have young children or an elderly relative living in your home.
A short-lived supply of fully hot water points to a problem with the lower heating element. Regular checking and maintenance will prevent damage but if the problem has already surfaced, call in a professional to test and replace the faulty element.
Your hot water heater might keep turning off due to several reasons. If it's a gas water heater, it could be due to issues with the gas supply, a dirty or damaged thermocouple, or a clogged pilot tube. If it's an electric water heater, it could be due to problems with the thermostat or heating elements.
Bad Heating Element
If your heating element goes bad, this lowers the temperature of your water and greatly affects how much hot water you get. So, if you start out with hot water, but then it goes cold fast, it could be that the water isn't getting heated anymore.
Put one probe from the multimeter on the reset terminal (beside the reset button) and the other probe on the left side terminal, which will be the one with power wires. If the multimeter's reading says 1, then the water heater thermostat most likely needs to be replaced. If it reads 0, it is functioning normally.
You're overusing hot water. The water heater tank size is too small for your household. Your hot water heater is tankless. Sediment or minerals have built up in your water heating system.
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. Of course, if you have a tankless water heater, you don't have to worry about this at all.
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.
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.
Although some manufacturers set water heater thermostats at 140ºF, most households usually only require them to be set at 120ºF, which also slows mineral buildup and corrosion in your water heater and pipes. Water heated at 140ºF also poses a safety hazard—scalding.
Strange noises – Knocking, clanging, taps, banging… any out of the ordinary sounds coming from your water heater are cause for concern. Such noises suggest your heating element is broken, you've got too much sediment in your tank, or there's an issue with your valves, connections, or water flow.
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.
While today's water heaters are better designed than older models, they still require regular maintenance in order to prolong their lives. 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.
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.
Most homeowners should flush their water heaters every 6 months or so, but if you have extremely hard water, you may want to do it more often. Flushing your hot water heater could be necessary as often as every few months depending on the mineral content of your local water supply.