Water Heater Running Out of Hot Water? Here's Why and How to Fix It
You turn on the shower and everything’s great for the first few minutes. Then, just as you’re covered in shampoo, the hot water disappears and you’re left shivering under a stream of ice-cold water. Have you ever been in this situation before?
If your water heater’s running out of hot water, there’s a reason behind it. Actually, there could be several. Maybe your water heater isn’t big enough for your household. Maybe there’s a hidden issue inside your system, like sediment buildup or a faulty heating element.
Before you assume you need a whole new unit, it’s important to figure out what’s causing the problem. And more importantly, how to fix it. Stick around because On Point Plumbing DFW has the answers.
Why Does My Hot Water Run Out Too Fast?
Nothing ruins a good shower like a sudden stream of ice-cold water when you’re covered in soap. If your hot water runs out fast, something’s wrong with your water heater. Common causes include incorrect sizing, thermostat issues, sediment buildup, and tankless flow rate limitations.
If your water heater is too small, it won’t keep up with demand. Check the gallon capacity to see if it matches your household’s needs. A low thermostat setting can also limit how much hot water is available, 120°F is ideal. If you have a tankless unit, running too many hot water sources at once may exceed its flow rate.
8 Common Reasons Your Water Heater Runs Out of Hot Water
If your hot water’s running out fast, it’s likely due to one of these problems:
Incorrect Sizing of Water Heater
A water heater that’s too small won’t be able to keep up with demand, especially in homes with multiple people using hot water at once. Here’s a guide to the right tank size for your household:
Household Size | Recommended Tank Size |
1-2 people | 30-40 gallons |
3-4 people | 40-50 gallons |
5+ people | 50-80 gallons |
Improper Thermostat Settings
If your thermostat is set too low, your water heater won’t heat the water enough to last. Setting your water heater to 120°F helps prevent scalding. This is a serious risk that led to 60,000 injuries and 110 deaths in the U.S. between 2016 and 2018.
Sediment Buildup in Tank-Style Water Heaters
Your water heater’s tank isn’t just filling with water. It also collects minerals from hard water. This sediment buildup can reduce efficiency and make it seem like you’re running out of hot water faster than usual. Flushing your water heater once a year can help keep it in great shape.
Incorrect Installation or Location Issues
If your water heater is installed in a cold garage or basement, it can lose heat faster. Poor pipe insulation causes hot water to lose heat before it even reaches your taps. Adding insulation or relocating your heater to a warmer area can reduce heat loss and save energy.
Flow Rate Limitations in Tankless Water Heaters
Tankless systems heat water as you use it. But if too many appliances or faucets are on at the same time, the system might not be able to keep up. If this happens often, consider upgrading to a unit with a higher flow rate.
Cold Water Sandwich Effect (Tankless Water Heaters)
Ever get hit with a blast of cold water between bursts of hot? That’s the cold water sandwich effect. It happens when hot water lags in tankless systems, especially when stopping and restarting the water. A recirculating pump or buffer tank can help.
Insufficient Recovery Time for Tank Water Heaters
If you’re using hot water faster than your heater can reheat the tank, you’ll run out quickly. If you have a large household, spacing out showers and dishwashing can help, or you may need a larger tank.
Worn-Out or Faulty Heating Elements (for Electric Water Heaters)
If one burns out, your water won’t get hot enough. If your water is suddenly lukewarm or not lasting as long, a broken heating element might be the issue.
Troubleshooting Tips for Running Out of Hot Water
If your hot water runs out too fast, start with a few quick solutions. Check the thermostat and set it between 120-140°F. Flush the tank to clear sediment buildup. Insulate pipes to prevent heat loss, and avoid using multiple hot water appliances at once. If the issue persists, it’s best to call a plumber.
Simple Fixes Homeowners Can Try
If your hot water isn’t lasting as long as it should, there are a few simple fixes you can try before calling a plumber.
- Adjust the thermostat temperature.
- Flush the tank to remove sediment buildup.
- Insulate exposed hot water pipes.
- Space out hot water use to give the system time to recover.
- Test and replace a faulty heating element in electric heaters.
When to Call a Professional Plumber
If you’ve tried all the options above and the issue still persists, call a plumber. You could have a leak, a broken dip tube, or a heating element issue. These are problems that aren’t always obvious but can affect your hot water supply.
Out of Hot Water? Call On Point Plumbing DFW
Tired of showers turning cold too soon? Whether it’s a thermostat issue, sediment buildup, or a broken heating element, On Point Plumbing DFW can diagnose and fix it fast. Call (469) 275-6994 today and enjoy hot water when you need it.