How to Flush a Water Heater: Step-by-Step Guide for Tank & Tankless
Key Takeaways
- Regular Maintenance: It is generally recommended to flush your water heater every 6 to 12 months, or more often if you have hard water.
- Why Flush?: Flushing removes mineral buildup (scaling) from your water heater, which can improve efficiency, prevent breakdowns, and extend the life of the unit.
- DIY vs. Professional: While flushing is a task many can do themselves, consulting a plumber is advisable if you are unsure or if issues arise.
Flushing your water heater regularly is an important maintenance task that can be done by most homeowners. This guide will provide a clear, step-by-step outline for flushing both tank and tankless water heaters, ensuring you understand the process and its benefits.
Understanding Water Heater Flushing
Flushing a water heater is a routine maintenance procedure to remove sediment buildup caused by hard water. This buildup, known as scaling, occurs when minerals like calcium carbonate in the water attach to the pipes and internal parts of the water heater. Over time, this scaling can reduce the area through which water can flow in the pipes, impacting the efficiency and performance of your water heater.
Why Flushing is Important
Flushing your water heater is essential for several reasons:
- Improved Water Flow: It helps ensure water moves freely and quickly through your system.
- Consistent Hot Water Supply: By removing scale, flushing helps maintain the required hot water output and reduces wait times for hot water delivery.
- Energy Efficiency: Scale buildup forces your water heater to use more energy to heat water, leading to higher energy bills. Flushing helps maintain energy efficiency by ensuring maximum water flow and efficient heat transfer.
- Preventing Breakdowns: Sediment can block or damage essential components, potentially leading to costly repairs or even a complete breakdown of the unit.
- Maintaining Water Pressure: Scaling can decrease hot water pressure at your outlets, affecting experiences like showers.
How Often Should You Flush?
For most homeowners, flushing a traditional tank water heater every six months is recommended, with more frequent flushing needed for areas with very hard water. Regular tank water heaters should be flushed at least once a year. For tankless water heaters, flushing at least once a year is a commonly accepted practice, and doing it more often is advisable, especially in areas with harder water.
How to Flush a Tank Water Heater
Flushing a tank water heater involves several steps to safely drain and clear out sediment. If your drain valve is clogged with sediment and barely any water comes out, you might be able to clear it with a zip tie or another soft object.
Steps to Flush
- Turn Off Power/Gas: For a gas water heater, turn the gas valve to the “off” position. For an electric water heater, turn off the power supply at the breaker.
- Turn Off Cold Water Supply: Locate the cold water shut-off valve at the top of the tank and turn it off.
- Open Hot Water Faucet: Open a hot water faucet in a sink or bathtub somewhere in your home to prevent a vacuum from forming in the tank.
- Connect Hose: Attach a garden hose to the drain valve at the bottom of your water heater tank. Direct the other end of the hose to a floor drain or outside where it can safely drain.
- Open Drain Valve: Open the drain valve on the water heater.
- Flush Until Clear: Allow the water to drain until it runs clear, indicating that most of the sediment has been removed.
- Close Drain Valve and Disconnect Hose: Once the water runs clear, close the drain valve and remove the garden hose.
- Refill and Restart: Turn the cold water supply back on to refill the tank. Close the hot water faucet you opened earlier once water starts flowing from it. Finally, turn the power or gas supply back on to your water heater.
How to Flush a Tankless Water Heater
Flushing a tankless water heater is a necessary maintenance routine to remove scale buildup, which is crucial for its long-term operation. Some tankless water heaters, like Intellihot units, are designed to resist scaling and may not require regular flushing.
What You’ll Need
To flush a tankless water heater, you will typically need:
- Basic Toolkit: For screwing and unscrewing pipes and components.
- Two Hoses: Two 6-foot hoses suitable for connecting to your tankless water heater’s cold-water inlet and hot water outlet.
- Descaling/Cleaning Agent: An appropriate quantity of liquid descaling agent to break down scale. Food-grade vinegar can often be used as an alternative; if using vinegar, let the pump run for 1.5–2 hours.
- Submersible Circulation Pump: A pump, ideally 1/5 hp or 1/6 hp, to circulate the descaling agent.
- Bucket: A 5-gallon plastic bucket that is not damaged by the descaling agent.
- Optional Flushing Kit: You can also purchase a tankless water heater flushing kit that includes all these components.
Steps to Flush a Tankless Water Heater
- Turn Off System: Turn off the gas valve for gas-powered units or the power for electric units. Then, turn off the tankless water heater’s inlet and outlet valves to stop water flow.
- Drain Heater: Drain any residual water from the system by removing the drain caps on the hot water outlet and cold-water inlet, collecting the water in a bucket. Exercise caution to avoid burns from hot water.
- Clean Filter (if applicable): If your unit has a prefilter at the bottom, wash it to remove any scale buildup.
- Attach Hoses: Connect one hose from the water heater’s inlet valve to the submersible pump in the bucket. Connect the second hose from the water heater’s outlet valve, leaving the other end in the bucket.
- Add Descaling Agent and Begin: Add the descaling agent to the bucket, open the inlet and outlet valves, and start the circulation pump. Let it run for the time specified by the descaling agent’s instructions, usually 45 minutes to a couple of hours.
- End of Flushing: Turn off the pump, then turn off the inlet and outlet valves. Disconnect the hoses and empty the bucket.
- Restart Water Heater: Reconnect the inlet and outlet water pipes. Replace the drain caps, turn on your gas line, and run a cold water outlet for a few minutes to clear any remaining descaling agent. Test the unit by turning on a hot water outlet.
Cost of Flushing
If you choose to hire a plumber, the cost to flush a tankless water heater can range from $100 to $600. For a DIY flush, the initial cost to purchase equipment such as hoses, descaling agent, a submersible pump, and a bucket can be between $102 and $185. Subsequent flushes will primarily only require the cost of the descaling agent, which is about $20–$60. Alternatively, a tankless water heater flushing kit can cost $110–$200.
Conclusion
Flushing your water heater is a simple yet crucial maintenance task that can significantly extend its lifespan and improve its efficiency. By following the steps outlined, whether you have a tank or tankless unit, you can prevent costly repairs and ensure a consistent supply of hot water for your home. Remember, regular maintenance is key to a well-functioning water heater.
FAQs
Why does my water heater make a popping or rumbling noise?
These noises are usually caused by sediment buildup at the bottom of the tank. As the heating element heats the water, trapped sediment can cause steam bubbles to form and burst, leading to these sounds. Flushing your water heater can help remove this sediment.
How can I tell if my water heater needs flushing?
Signs that your water heater might need flushing include:
- Reduced hot water pressure.
- Strange noises (popping, rumbling) coming from the tank.
- Rusty or discolored hot water.
- A noticeable drop in hot water availability.
- Higher energy bills without a change in usage.
What kind of descaling agent should I use for a tankless water heater?
Many manufacturers recommend specific descaling solutions, so always check your owner’s manual. Food-grade white vinegar is a common and effective DIY alternative. It’s safe, inexpensive, and generally works well to break down mineral deposits.
Can I flush my water heater myself, or should I hire a professional?
Flushing a water heater is a task many homeowners can successfully perform. The steps are straightforward, and the necessary tools are readily available. However, if you’re uncomfortable with the process, or if you encounter any difficulties, it’s always best to hire a qualified plumber to avoid potential damage or injury.
What happens if I don’t flush my water heater regularly?
- Not flushing your water heater regularly can lead to several problems:
- Reduced Efficiency: Sediment buildup acts as an insulator, forcing the unit to work harder and consume more energy to heat water, leading to higher utility bills.
- Decreased Lifespan: The increased strain on the heating elements and tank can shorten the overall lifespan of your water heater.
- Damage and Leaks: Sediment can corrode the tank lining or clog components, potentially leading to leaks or complete unit failure.
- Inconsistent Hot Water: Sediment can interfere with the heating process, resulting in less hot water or fluctuating temperatures.
More Water Heater Guides You May Find Helpful
Looking to learn more about keeping your water heater running smoothly? Check out these helpful guides:
How long does a hot water heater last
What size tankless water heater do I need
What are the signs of a failing water heater
How long does a water heater take to heat up
What causes a tankless water heater to stop working
Should I repair or replace my water heater
What causes gas water heater to stop working
What causes an electric hot water heater to stop working
What causes a water heater to leak
What to do if water heater leak
Water heater breaker keeps tripping? what to do
