There's a drain valve at the bottom of the water heater tank that can be opened to allow water to drain out. You don't need to literally drain the water out of the water heater, just open the valve and let some water come out; Rheem says a few quarts is fine.
It's difficult to put an exact amount of how much a relief valve should leak as there is many variables that can affect the amount of leakage, however, a relief valve can leak up to 12L in a single day and this is classed as normal operation.
Typically, draining a 40-gallon water heater takes somewhere between 30 and 45 minutes. The overall time is heavily influenced by the size of the unit and the rate at which the water can exit the tank through the drain valve.
Make certain the drain valve is completely closed. Open the shut-off valve in the cold water supply line. Open each hot water faucet slowly to allow the air to vent from the Water Heater and piping. A steady flow of water from the hot water faucet(s) indicates a full Water Heater.
Generally, it takes about 30 minutes to an hour to drain the average 50-gallon water heater completely. However, the time may vary depending on the size of the tank and the amount of sediment present. After the water heater tank is empty, it's time to flush it.
Sediment buildup is a common issue in water heaters, particularly in areas with hard water. Over time, minerals such as calcium and magnesium can accumulate at the bottom of the tank, forming a layer of sediment. This sediment can impede the flow of water, causing the heater to drain slowly.
Step 2: Shut off the Water
It's important to wait for the water inside the water heater to cool before flushing as it can remain scalding hot for a long time. You can start this step at night after everyone in your household has no need for hot water.
It's not always necessary to drain the entire hot water tank. Since sediment and buildup settle on the bottom of the tank, you may drain a few gallons of water at a time until most of the sediment is flushed out. This also prevents homeowners from accidently damaging the hot water heater by turning it on without water.
Rumbling, popping, or hissing sounds
Water heater noises are a common indicator of sediment buildup in water heater tanks. If your water heater is making popping, creaking, hissing, or rumbling sounds, it's likely because minerals in the water have formed a layer on the surface of the water heater element.
Water Leaking From The Bottom
If you notice water leaking from near the base of your water heater, it could be an issue with the drain valve. The drain valve is designed to empty the water tank when needed, such as during maintenance. Solution: Inspect the drain valve for corrosion and replace.
Step 5: Turn on a hot water faucet
This helps to alleviate pressure and allows the tank to drain quicker.
While draining the tank, keep the pressure relief valve open. This allows air to enter the tank, facilitating a smoother and faster draining process. It also prevents a vacuum from forming inside the tank, keeping the water flowing consistently and preventing potential damage to the tank structure.
Refilling the tank
Wait at least 15 minutes for the tank to fill up, then turn the breaker back on (electric tanks) or turn on the gas and relight the pilot (gas tanks). That's it! Your water heater is now drained, flushed, refilled and ready to let the good times flow.
Every water heater has a T&P valve as a safety feature to release water if too much water pressure builds up. If you see water leaking from the T&P valve, first make sure the temperature is not set too high. If the temperature is too high, it may cause excessive pressure and trigger this safety mechanism.
A slight leak may occur if your water heater's pressure relief valve has not been opened for a while, say a few years. While this leak is normal and may not be an indicator of a problem with the water heater system, you may need to replace the valve if the leak becomes more serious.
Water heaters have a drain valve on the front near the bottom of the unit. This valve has the same threads as a spigot. Attach a garden hose to the valve to direct the water into a drain or outdoors. A washing machine hose will also work if there is a drain nearby.
Perform a vinegar soak.
Vinegar is part of clearing and cleaning a clogged drain, and it's also helpful in removing sediment from water heaters. After you've drained your hot water tank, you can pour a gallon or so of vinegar through it.
Dor-Mar Heating and Air Conditioning recommends flushing your water heater annually to remove sediment build up inside.
It is recommended that you flush your water heater at least once per year. Doing so will help to prevent the potential problems that sediment can bring over time. Typically, it takes one to two hours to flush a water heater. The size of your tank will impact the amount of time it takes to drain.
You'll know when your water tank is full when the hot water tap, which you turned on earlier, runs normally without any residual air coming out.
Should you drain your hot water heater every year? Yes, but that's really just the bare minimum. You should really drain and flush your water heater twice-per-year: once in the spring, and then again in the fall. The reason why comes back to what a water heater is flushing out: minerals and sediment.
You may need to loosen the valve with a flathead screwdriver. Generally, this step takes 10 minutes or less. The size of the tank dictates exactly how long it'll take to drain. For example, if you have a 50-gallon tank flowing at 10 gallons per minute, you can expect for it to fully drain in about 5 minutes.
Over time, the number of sediment increases, leading to problems with the water heater. Sediment can begin the process of corrosion and can clog the valves inside the water heater tank, leading to leaks and other issues. Both of these problems decrease efficiency and can result in costly repairs.
Partial Fluid Replacement: Unlike a flush, a drain and fill only replaces a portion of the old fluid, about 30-50% of the total fluid in the system. Simpler Process: It's a process that can often be performed without special equipment.