Step‑by‑Step Guide: How to Flush Your Water Heater for Maximum Efficiency

Sediment buildup can silently degrade your water heater’s performance. To maximize the water heater’s efficiency, you need to flush the water heater twice per year. With Central Air Heating, Cooling & Plumbing’s help, you can tackle this maintenance yourself or let our professional technicians take care of it for you.

Why Flushing Your Water Heater Matters

Water heater maintenance isn’t just a good idea. It’s integral for the longevity of your water heater. Regular water heater flushing removes mineral and sediment buildup, improving the water heater’s efficiency. Besides eliminating popping and rumbling sounds, this maintenance task can lower your energy costs, boost water quality, prevent corrosion, and reduce the likelihood of premature failure. 

How Often Should You Flush Your Water Heater? 

At Central Air Heating, Cooling & Plumbing, we typically recommend flushing your water heater at least twice per year. At a minimum, you’ll need to do this once per year. Ideally, you should flush it in the spring and fall to avoid peak demand seasons. If you have hard water or heavy sediment, you may need to flush the water heater more often.

Step-by-Step Guide: Flushing Your Water Heater

To flush a water heater, you’ll need to gather a few essential tools.

Tools and Preparation

You’ll need to gather: 

• A garden hose that’s long enough to reach your drain or yard
• A screwdriver or wrench
• A bucket or towel
• Protective gloves to prevent burns
• Eye protection to protect your eyes from the hot water

Steps in Flushing Your Water Heater 

To flush your tank, use the following steps.

• Turn off the power or gas. The electricity should be shut off at the breaker. Set gas water heaters to off.
• Switch off the cold water supply.
• Open up a hot water tap in the home so that the pressure can be reduced when you start draining the tank.
• Attach a hose to the drain valve to drain the water into a safe place.
• Open the drain valve to drain the tank. Mind the hot water.
• Close the drain valve when you’re done. Disconnect the hose and refill the tank. Note any sputtering from the open hot water tap.
• Turn the power back on or relight the pilot light. Monitor for leaks, which may indicate valve issues.

Timing & Additional Tips

Often, this process will take about 30 to 60 minutes. If the drain valve is clogged, you’ll need extra tools. You can also reach out to our plumbers if your water heater needs repairs.

Signs Your Water Heater Needs Flushing Promptly 

You should flush your tank right away if you notice: 

• Loud rumbling or popping noises
• Rust-colored water
• Discolored water
• Lower hot water output
• Declining water pressure
• Issues with heating the water

When To Call Central Air Heating, Cooling & Plumbing

Whether you need a replacement for your old water heater or a simple repair, our team is here to help. Give us a call if you’re experiencing any of the following situations.

• You noticed leaks, corrosion, or clogged valves. 
• You feel unsafe and want a professional HVAC technician to handle the T&P valve checks, maintenance, or anode rod issues.

When you need help, we’re only a phone call away. We can schedule your seasonal maintenance so that your water heater is efficient all year long.

Frequently Asked Questions 

Over the years, we’ve found that Portland residents tend to ask a few common questions about what it takes to flush a water heater.

Can I use any hose to flush my water heater?

Absolutely. It doesn’t take a special hose to flush your water heater, so the hose you currently have at home likely works.

However, it’s important to remember that the hose must be long enough to get water from your water heater to a drain or the exterior of your home. If it isn’t long enough, you’ll need to get a different hose.

While flushing a water heater can be done on your own, you can also hire one of our plumbers to handle your maintenance. If you do, we’ll make sure to bring our own hose just in case the one you have at home isn’t the right length.

Should I flush my tankless water heater the same way?

No, you shouldn’t flush your tankless water heater like you would a traditional one. Tankless water heaters don’t have a tank that stores water. Instead, they heat water on demand. 

If you do have a tankless water heater, your routine maintenance will involve descaling the unit using special valves and cleaners. This process can vary between different manufacturers, so you should check the manufacturer’s guidance before you begin. You can also consult with one of our experienced plumbers if you need extra help.

What if the sediment won’t flush out?

After you spend about half an hour to an hour draining the tank, you can flush it using a hose. It may take more than one flush to get it clean, especially if it has been a while since you flushed your water heater last. 

For extra dirty water heater tanks, try flushing multiple times. When you are done, the water should run clear. If it is still dirty, you may need a professional cleaning from one of our plumbing experts. 

Is water temperature critical after flushing?

Yes, the water temperature in your tank is incredibly important for your safety and comfort. To avoid Legionnaires’ disease and other types of bacterial growth, you need to set your water temperature to 120°F. However, you don’t want the temperature to be too high because anything above 120°F increases the likelihood of scalding. 

After you flush your water heater, take a moment to adjust the thermostat and make sure it is set correctly. If you are unsure if the thermostat’s sensors are accurate, you can also test the water temperature produced after the unit has warmed up completely. 

Does flushing void the warranty?

No, flushing does not void the warranty. In reality, your manufacturer’s warranty likely requires you to meet important maintenance requirements. For water heaters, the main maintenance expectation is to regularly flush the unit.

You will need to read through your manufacturer’s warranty to see how often it needs to be flushed. In most cases, the warranty will require you to flush the tank at least once per year.

How long does it take to flush your water heater? 

As a general rule, it takes around 30 to 75 minutes to flush your water heater. You’ll need to spend around 20 to 60 minutes draining your tank. Then, you’ll need to flush it for 10 to 15 minutes until the water runs clear. 

However, this timeline can vary based on how big your tank is. If you have a large home or a high water demand, you likely have many extra gallons in your tank. Additionally, the process may take longer if you have to flush the water heater multiple times.

Consult With the Water Heater Experts

Looking for top-rated water heater maintenance? Schedule a professional flush with Central Air Heating, Cooling & Plumbing today. Our licensed technicians will clean, inspect, and optimize your system for efficiency, safety, and lasting performance. Book your water heater service online or call us now!