How to Drain Water Heater Tanks in Westminster
Here is how to drain water heater tanks in Westminster safely: turn off the power or set the gas to pilot, let the water cool for several hours, close the cold supply, attach a hose to the drain valve, and flush until the water runs clear. If the valve sticks or leaks, call to be connected with a local provider.
- Tank water can be hot enough to scald, so let the heater cool for several hours before you open the drain valve.
- Turn off the power at the breaker for an electric heater, or set a gas heater's control to pilot or vacation, before draining.
- The City of Westminster says it adds calcium to its water, which increases hardness, so mineral sediment can build up in a tank over time.
- Always refill the tank completely before turning the power back on, because heating an empty electric tank can ruin the elements.
- An old drain valve that will not close, or a tank that leaks from the bottom, is a reason to stop and call for help.
What to do first
- Turn off the power at the breaker for an electric water heater, or turn a gas heater's control knob to pilot or vacation.
- Wait several hours, or overnight, so the water inside the tank cools down.
- Close the cold water supply valve on the pipe that feeds the top of the tank.
- Attach a garden hose to the drain valve near the bottom and run it to a floor drain or outside to a spot that slopes away from the house.
- Open a hot water faucet upstairs so air can enter the tank and the water drains freely.
How to drain water heater tanks: what are the basic steps?
To drain a tank water heater in Westminster, shut off the heat source, let the water cool, close the cold supply, connect a hose to the drain valve, open a hot faucet, and open the drain valve. When it is empty, flush with a little cold water, close the valve, and refill before turning the heat back on.
- Turn off the breaker (electric) or set the gas control to pilot or vacation.
- Let the tank cool for several hours.
- Close the cold water supply valve at the top of the heater.
- Connect a garden hose to the drain valve and run the other end to a floor drain or outdoors.
- Open a hot water faucet in the house to let air in.
- Open the drain valve slowly and let the tank empty.
- Open the cold supply for a short burst to stir up and flush sediment, then let it drain again. Repeat until the water runs clear.
- Close the drain valve, remove the hose, and open the cold supply to refill.
- Leave the hot faucet open until water flows steadily with no sputtering, then close it.
- Restore power or relight the gas following the label on the heater.
Read the label on your own heater first. Brands and models differ, and the manufacturer's steps come first.
Why would you need to drain a water heater in the first place?
Most people drain a water heater to flush out mineral sediment that settles on the bottom of the tank. Others drain it before moving a heater, before a repair, or to protect an empty house. Sediment can make popping or rumbling sounds, slow down heating, and cloud the hot water.
When water is heated, some of the minerals in it drop out and settle. Over months and years that layer can grow. Flushing once in a while keeps that layer thin.
- Popping, crackling or rumbling sounds while the heater runs.
- Hot water that runs out sooner than it used to.
- Gritty bits or flakes in faucet aerators.
- Cloudy or rusty-looking hot water.
Rusty hot water can also point to a tank that is wearing out, which is a different problem. Our guide to water heater repair vs. replacement covers that decision.
Is it safe to drain a water heater yourself?
Draining a water heater is a common homeowner task, but it carries real risks: scalding water, gas and electrical controls, and old valves that can break. It is reasonable to do yourself if the heater is easy to reach, the valve works, and you follow the label. If any of those are in doubt, call for help.
- Burns: Do not drain a hot tank. Let it cool for hours first.
- Electric heaters: Turn the breaker off before you start, and keep it off until the tank is completely full again.
- Gas heaters: Set the control to pilot or vacation. If you ever smell gas, leave the house and call your gas utility from outside.
- Water near power: Keep the hose and any spills away from outlets, cords and the electrical panel.
A water heater that sits in a tight closet, an attic, or above finished rooms is harder to drain without a mess. That is a good time to let a provider handle it.
Need help now? Call to be connected with a local provider in Westminster who can check availability for your address.
What if the drain valve is stuck, clogged or leaking?
If the drain valve will not open, will not close, or drips after you close it, stop and call for help. Many water heaters ship with plastic drain valves, and older ones can crack or seize. Forcing them can turn routine maintenance into a leak you cannot stop until the tank is empty.
A few safe things to try first:
- Check that the cold supply is closed and a hot faucet is open. A vacuum in the tank can stop the flow.
- Disconnect the hose and check it for kinks or a sediment plug.
- Put a cap on the valve outlet if it keeps dripping after you close it, and keep a bucket under it.
If water is coming from the bottom of the tank itself, not the valve, the tank may be failing. Shut off the cold supply and the power or gas, and see our water heater repair page for what to expect next.
How often should you flush a water heater in Westminster?
Many manufacturers suggest flushing a tank water heater about once a year, and homes with harder water may benefit from doing it more often. Check the manual for your own model, because its schedule is the one that counts.
Watch for the signs of buildup instead of only the calendar. If you hear rumbling, find flakes in aerators, or notice the hot water running out sooner, it is probably time. If you have never flushed an older heater, be careful. Years of sediment can clog the valve, and some older valves do not seal well once opened. A provider can look at the valve first and explain whether a flush makes sense.
Where should the water go when you drain the tank?
Run the hose to a floor drain, a laundry sink, or outside to a spot that slopes away from the house. The first water out can be hot and full of sediment, so keep it away from plants, pets and people, and do not let it pool against your foundation.
The drain end of the hose needs to be lower than the drain valve, or the water will not flow.
In late fall and winter, think about the weather. Water left in a hose outside can freeze, so drain and coil the hose when you finish.
What happens during the visit if you call for help?
When you call, you are connected with a local plumbing provider who checks availability for your address. During the visit, the provider looks at the heater, the drain valve, the gas or electrical controls and the venting, then explains what they found and your options. You should get a written quote before any work begins.
- An inspection of the tank, valve, connections and the area around the heater.
- A plain explanation of whether a flush, a valve change, a repair or something else makes sense.
- A written quote you can review before you agree to anything.
If your problem is no hot water at all, start with our checklist on no hot water and what to check first.
What should Westminster-area homeowners know before draining a water heater?
Water in the north metro carries minerals that settle in a water heater over time. The City of Westminster says it adds calcium to its water, which increases hardness and helps form a protective calcium carbonate scale inside pipes. That same hardness is part of why sediment builds up in tanks.
Neighboring cities differ. Thornton's 2026 Water Quality Report says hardness averaged around 230 mg/L, or 13.5 grains per gallon, in 2025, and that "Thornton's water treatment plants do not remove hardness." Broomfield's current water quality report lists hardness at 1.5 to 7.3 grains per gallon. If you live in Thornton or Northglenn and hear your heater rumbling, regular flushing is worth a look.
Know your shutoffs before you start. The City of Westminster says the main water shutoff is just inside the home where the service line enters, usually in the basement or crawlspace. If the cold supply valve at the heater will not close, the main is your backup.
Timing matters too. In the Denver area, NWS Boulder lists the average first freeze as October 7th, so a hose left outside after draining can freeze on a cold night. Westminster's own freeze guidance also tells residents to turn off and drain irrigation sprinkler systems, so it is a good season to handle both jobs. Homes in Westminster, Arvada, Broomfield and Thornton can call to be connected with a local provider for help.
Related pages
Questions people ask
How do I drain my water heater step by step?
Turn off the power or set the gas to pilot, let the tank cool, close the cold supply, connect a hose to the drain valve, open a hot faucet, then open the drain valve. Flush with short bursts of cold water until it runs clear, close the valve and refill before restoring heat.
What is the easiest way to learn how to drain water heater tanks at home?
Start with the label and manual on your own heater. They show where the drain valve, cold supply and controls are, and the steps in this guide follow the same order most manufacturers use.
Do I need to turn off the water heater before draining it?
Yes. Turn off the breaker for an electric heater, or set a gas heater to pilot or vacation, before you open the drain valve. Heating an empty or half-empty tank can damage it.
How long should I wait for the water heater to cool before draining?
Wait several hours, or overnight if you can. Tank water can be hot enough to scald, and the first water out of the drain valve is often the hottest.
Why is my water heater not draining when I open the valve?
Usually the cold supply is still open, no hot faucet is open, the hose is kinked, or sediment is clogging the valve. Open a hot faucet to let air in and check the hose before trying anything else.
Should I open a hot water faucet when draining a water heater?
Yes. An open hot faucet lets air into the tank so the water can drain freely. Without it, a vacuum can slow or stop the flow.
How do I flush sediment out of my water heater?
After the tank drains, open the cold supply for a few seconds at a time to stir up the sediment, then let it drain again. Repeat until the water coming out of the hose looks clear.
What does it mean if my water heater is making popping noises?
Popping or rumbling often means sediment has built up on the bottom of the tank. Flushing can help, but if the noise stays, have a provider look at it.
Is it bad to never flush a water heater?
Skipping flushes lets sediment build up, which can make the heater noisy and less efficient. If an older heater has never been flushed, have the drain valve checked before you open it, because heavy sediment can clog it.
How often should I drain my water heater in Westminster, Colorado?
Many manufacturers suggest about once a year, and homes with harder water may need it more often. The City of Westminster says it adds calcium to its water, which increases hardness, so check your heater's manual and watch for signs of buildup.
What do I do if the water heater drain valve will not close?
Close the cold supply, leave the power or gas off, and cap the valve outlet if you can, with a bucket underneath. Then call to be connected with a local provider, because a failed valve may need to be replaced.
Do I have to refill the tank before turning the power back on?
Yes. Leave a hot faucet open while the tank refills, and wait until water flows from it steadily with no sputtering. Only then turn the breaker back on or relight the gas.
Is it safe to drain a gas water heater myself?
It can be, if you set the control to pilot or vacation, let the tank cool, and follow the label. If you smell gas at any point, leave the house and call your gas utility from outside.
Can draining a water heater fix lukewarm water?
Sometimes. Heavy sediment can slow heating, so a flush may help. Lukewarm water can also come from a failed element, thermostat or gas part, which a provider can check.
Why is the water coming out of my water heater brown or rusty?
Brown water during a flush is often loosened sediment and usually clears as you flush. Rusty hot water that does not clear can be a sign the tank is wearing out and should be looked at.
Where is the main water shutoff in a Westminster home?
The City of Westminster says the main shutoff is just inside the home where the service line enters, usually in the basement or crawlspace. Find it before you start in case the heater's own supply valve fails.
Should I call a plumber to drain my water heater?
Call if the heater is hard to reach, the valve is stuck or leaking, you smell gas, or the tank itself is leaking. A provider can inspect it, explain options and give a written quote first.
How do I check if a Colorado plumber is licensed?
Use DORA's online license lookup, which lists Plumbers as a profession. Colorado's State Plumbing Board also says plumbing contractors must show their registration number and their responsible master plumber's license number on websites and bid sheets.
Talk to someone about your plumbing problem
Call to be connected with a local provider who can check availability for your address and explain the next step.