The hot water heater comes about as close to being maintenance-free as any household appliance. Once it is properly installed and set to the right temperature, very little is required to keep it functioning efficiently for a long time. However, there are a few steps you should take to prevent leaks and to ensure your water heater maintains it’s efficiency. While each manufacturer has its own checklist of recommended periodic maintenance steps, in general, what should be done is as follows.
Water Heater Maintenance Schedule
Once every two months:
Inspect the water heater. Check for water leaks, either at plumbing joints or, for tank-type water heaters, coming from the tank itself. Check all plumbing joints for excessive or unusual corrosion. If the water heater is gas-powered, check the condition of any flex hose and the couplings (including smelling for gas leaks), and make sure no flammable materials are near the area of combustion. On a tank-type water heater, test the temperature and pressure relief valve to make sure it opens and closes freely. Turn on a nearby hot water tap and listen for unusual sounds (especially hammering or crackling) that might indicate a more serious water heater problem.
Once every six months to a year:
Flush your water heater by draining several gallons of water through the drain valve. This will remove any sediment that has built up inside.
Once every year:
After the water heater is two or three years old, the anode rod should be removed and inspected once every year. Some pitting and surface corrosion are normal and to be expected. Large chunks of metal coating missing from the surface indicate that it should be replaced.
Water Heater Maintenance: Flushing your water heater
Flushing a water heater tank is an important part of water heater maintenance and should be performed once every six months (particularly in hard water areas) to a year. It involves, simply, draining several gallons of water from the bottom of the water heater tank, through the drain valve, in order to draw off sediment—minerals and other minute solids that are found in all water systems—that normally accumulates at the bottom of the tank over time. That sediment impairs the water heater’s performance and shortens its lifespan, so this flushing should be done regularly. Draining the hot water tank is also necessary to perform some repairs.
WARNING: Water heaters are typically factory-set to heat water to 125° F, which is hot enough to inflict first degree burns on skin on contact. When turned all the way up to maximum temperature (which can be anywhere from 160ºF to 190º F) serious injuries can result from even indirect contact with the water. Always take precautions to avoid coming into contact with heated water.
The first step is to turn off power to the water heater—gas at the on/off control knob, electric at the circuit breaker box or the separate on/off switch box. Keeping in mind that the water inside the tank is hot and will remain so for quite some time even after the power is turned off, it is best to use some of the hot water or to wait several hours to allow the water in the tank to cool before proceeding with the flushing.
When you’re ready to flush the water heater, turn off the water supply at the cold water shutoff valve. Open a hot water tap that is nearby and is no lower than the level of the water heater, and leave it open. This will allow air to enter the tank as it empties. Securely connect an ordinary garden hose to the drain valve located near the bottom of the water heater. Make sure that the hose is long enough to reach a drain or sump pit (and it should at no point be higher than the drain valve since the draining process will be gravity-fed). Once the hose is in place, open the drain valve. It will have either a dial or a slot for a flathead screwdriver that you will have to turn counter-clockwise to open. At this point, the tank should begin draining. After a few gallons have drained, collect some of the water in a bucket or run it through a screen to inspect it for sedimentation amounts.
If very little sediment is found and the water flowing from the tank is otherwise clear flush several more gallons and then stop the process. Regularly flushing the tank every six months will typically produce this type of result. If heavier sedimentation is found, however, continue to drain the water, occasionally turning the cold water supply back on to help stir up and remove any materials still in the tank. Continue doing this until the water flowing from the tank is clear and sediment-free.
Once your water tank has been completely flushed, or you have finished making any repairs, you can refill the tank by closing the drain valve and turning the water supply back on. Do not turn the power to your water heater on until the tank is completely full. Check the hot water tap you opened earlier. When water is coming out of it at full stream you know your tank is full and you can turn the power back on.
The only time it should be necessary to completely empty a tank is when the drain valve needs to be replaced, or when the water heater itself needs to be replaced. To do this, follow the same procedures as with flushing, but leave the drain valve open until no more water flows from it.
You may want to consider installing a sediment filter on your incoming water line. Read our post regarding sediment filters. It is focused on tankless water heaters, but sediment filters can be very beneficial for traditional tank type water heaters as well.
Other Water Heater Maintenance Tips
While flushing the water heater, should heavy white sediment be found, it may be an indication that the anode rod has deteriorated. It should, therefore be inspected and, if necessary, replaced before refilling the tank. See below to learn how to do this.
Still not sure how to flush your water heater? Try watching this video:
Water Heater Maintenance: Replacing the anode rod
Checking and replacing your water heater’s anode rod is a key part of proper water heater maintenance. One of the biggest potential problems for a water heater is corrosion. When metal and water mix, water invariably wins. Sooner or later the metal will corrode and crumble into nothingness. When the water is heated, the process is accelerated. For that reason, given enough time, water will eventually get the better of any water heater, particularly the water heater’s tank, and end its useful life.
That is why most modern tank-type water heaters include a device known as an anode rod, which is a passive yet effective corrosion preventative. Also sometimes referred to as a sacrificial rod, it is a long, narrow, solid pipe that is suspended inside the tank and affixed from the top of it. It’s typically made of aluminum or magnesium or zinc, or a combination of these metals, all of which are particularly susceptible to the corrosive process, much more so than steel and its alloys. The theory behind the anode rod is that, because corrosion tends to feed on its most vulnerable targets first, the anode rod, which serves no other purpose, will suffer the corrosion that the steel sides of the tank otherwise would, thereby extending the life expectancy of the tank.
Eventually, though, the anode rod will completely corrode and dissolve, and will therefore no longer be able to perform its function. The usual useful life expectancy for an anode rod is four to six years; less if the water is particularly hard, and more if a lower water temperature is normally used. Periodically checking the condition of the anode rod is therefore, an important component of regular water heater maintenance. The first time should be when the water heater is no more than two or three years old.
In order to check the condition of the anode rod, it will have to be removed from the tank. The first step is to turn off power to the water heater—gas at the on/off control knob, electric at the circuit breaker box or the separate on/off switch box. Next, you will have to close the cold water shutoff valve, and open a nearby hot water tap to allow the pressure inside the tank to equalize. In addition to these steps, also draw off a few gallons of water through the drain valve, in order to clear any remaining water from the hot water pipes that are above the level of the top of the tank. The tank itself need not be otherwise drained.
Once these steps have been taken, the anode rod can be safely removed. Its connection point will be on the top of the water heater, where it is threaded into the top of the tank. It may be located under a cap that will have to be pried off first. Using a properly sized wrench or socket (the size is almost always 1 1/16 inch), turn it counter-clockwise until it clears the threads. A small amount of water may gush up from the opening when this happens. Then carefully remove the anode rod straight upward. Try not to knock it against is the inside of the tank or the sides of the opening, or parts of it may break loose and fall inside the tank, to eventually become more sediment that has to be removed during a later flushing process.
Inspect the anode rod carefully. Some pitting and surface corrosion is normal and to be expected. Large chunks of metal coating missing from the surface or portions of its length entirely missing indicate that it should be replaced. A new one, preferably one pre-cut to the proper length and intended for the particular water heater model, can be purchased at a plumbing supply house or a hardware store. Whether reinstalling an existing, still-good anode rod or installing a new replacement for it, this can easily be done on a DIY basis. Simply wrap the threads in Teflon tape, carefully slide the rod back into the hole, and tighten it securely.
Once the anode rod is securely back in place, open the cold water supply valve, allow the water level in the tank to top off—indicated when water flows freely from the nearby open hot water tap—turn that tap off, and turn the power to the water heater back on.
Still unsure about how to change an anode rod? Try watching this video:
Is your water heater leaking? Then watch this video!