Why Do I Run Out Of Hot Water So Fast?

Gas boiler on blue background. Gas boiler home heating. 3d

Fleeting Heat

When you get up on a winter morning in St. Louis, Missouri, are you one of those that it takes a hot shower to get woke up and moving? How does your day go if you run out of hot water during that shower? Probably not as good as you would like, right? Does this mean you need a new water heater, water heater repair, or basic maintenance? 

What maintenance do water heaters need?

Annual maintenance is recommended by plumbing experts. This will extend your water heater’s lifespan and save you money too. In most homes, it isn’t necessary to have this done by a professional, but if you have any issues or you’re unsure, schedule a water heater repair and maintenance appointment. 

The first thing you need to do is turn off the power source. For an electric water heater, you can do this by flipping the circuit breaker off. For the gas water heater, turn the pilot light off. 

A Mini-Flush

Flushing the water heater tank is one of the first things a plumber will do when on a water heater repair service call. This prevents corrosion and rust from happening as it removes any sediment that has collected inside the tank. These steps are a mini-flush, which isn’t quite as thorough as a full flush the plumber would do.

  1. Position a bucket under the water heater tank drain valve.
  2. Counterclockwise, turn the valve and allow up to two gallons of water to drain. This will be very hot water, wearing long sleeves and gloves should be considered. 
  3. Now close the valve with clockwise turns. 

The T&P Valve

The T&P valve (temperature and pressure) is a relief valve and is a feature critical to your safety. When there is too much pressure built up inside the tank, or the temperature reaches an excessive height, this valve will automatically open, relieving the pressure. 

Most T&P valves are installed on the top of the tank, some are on the side wall. There will be a discharge tube extending downward. To test the T&P valve:

  1. Position a bucket under the discharge tube.
  2. Lift the valve lever to open it and release any hot water into the bucket through the discharge tube. Again, the water will be very hot, wearing long sleeves and gloves is recommended. 
  3. Let the water drain for a few seconds and then release the lever so that it closes and shuts the water off.

If the T&P valve leaks after you’ve completed these steps, call a plumber for a water heater repair service to replace the valve.

Lower the Temperature

The typical setting for water heaters is between 130 degrees and 140 degrees. The DOE (Department of Energy) encourages homeowners to lower the temperature to 120 degrees to save on energy. This will also minimize the number of mineral deposits accumulating that can clog your water heater and lead to more water heater repairs needs or require replacing sooner than expected. 

Tankless water heater in the bathroom

What is the most common problem with water heaters?

Leaking water heaters are the most common water heater repair calls plumbers to receive. Many times, when a water heater begins leaking, tightening the water line connections at the water heater and at the source will stop the leak. 

However, if a water heater is leaking from the side or under the tank, it is beyond water heater repair. No matter where you live and what type of water system you have, it is common to have mineral deposits. These will begin corroding the inside of the water tank.  Over time, this will cause microscopic cracks or fractures in the tank, and water begins to leak. 

How long does it take for a water heater to heat up?

In a 50-gallon water heater that is operating at full capacity, the water will heat up by 40 degrees within 40 minutes for a gas-powered water heater and within 50 minutes for an electric-powered water heater. 

Why is my water heater making sound?

Some sounds are normal, some are not. Here are 5 commonly heard sounds and what they typically indicate: 

  • Banging and Rumbling: These are the most common sounds from water heaters and typically it is because of sediment build-up. They are like mini-explosions and often, flushing the water heater tank will stop those sounds. If it doesn’t schedule a water heater repair service, you may have something more complex with your plumbing. 
  • Crackling and Hissing: These are common sounds from electric-powered water heaters and if they are occasional, it is normal. If they are persistent, however, you should call for a water heater repair service and have the unit inspected. 
  • Ticking: A ticking water heater can be alarming, but fortunately, in most cases, it is just a water pressure change. If the noise doesn’t stop, a water heater repair service call should be scheduled. 
  • Popping: This sound is usually caused by sediment build-up in the tank. You can do a flush and see if that helps, but most likely, you’ll need a water heater repair to replace the heating element. 

How do you clean sediment out of a hot water heater?

To flush sediment from a water heater, you’ll need to do a mini-flush as we described earlier, or a full flush. A full flush is done in the same manner except for a bucket under the drain valve, you’ll connect a garden hose to it and run the other end out a door. Then let the entire tank empty through that hose. This is a common water heater repair call and is well worth paying to have it done versus having to buy a new water heater.

Why is there a leak under my water heater?

This is typically from the tank leaking along the bottom, and it is beyond any water heater repair at this point. The leak will begin as more sediment keeps building up, causing the bottom and inside of the tank to corrode and rust, creating cracks and holes.

How long should a water heater last?

Most tank-style water heaters will last between 8 and 12 years, some have been known to last for 15 years. This is will all depend on the water quality and your maintenance practices, like flushing the unit annually. 

When do I need water heater replacement?

There are five things about a water heater that is telling you to get a replacement: 

  1. The age – if it reaches 8 to 10 years and starts needing water heater repairs every year, it is time to replace the unit. 
  2. Rusty Water or Leaking Valve – the unit has become corroded and rusted inside the tank. It is time to replace the unit.
  3. Water Heater Noise – if the noises we discussed earlier don’t stop after flushing, it is time to replace the unit.
  4. Water Heater Leaking – if the unit is leaking from the bottom or sides, it is time to replace it.
  5. Not Heating – if you have flushed the unit and it still isn’t heating the water, it is time to replace the unit.

In Closing 

If you’re going to buy a new water heater, you may look at the tankless water heater systems, which can be ideal for many homeowners. But for your home, you may wonder, are tankless water heaters a good alternative?

The first thing you need to realize is that there is some mathematics to purchasing a tankless water heater system. You’ll need to know how much water your home uses in one day and from what source. Then you’ll need to choose a tankless water heater with the GPF, which is the flow of hot water it will produce. 


For a home with 10 kids, a tankless water heater may not be the best solution. If you have a small family or a household of one, then, yes, a tankless water heater could be a great alternative.

If you’re interested in a tankless water heater in St Louis, MO, call the team at Flow King Rooter at 314-348-7503 today.