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Water Heater Flushing Guide

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Flushing of the water heater is a routine maintenance task, but it isn't one you want to overlook. Failure to flush when needed can drastically reduce the life of the water heater or even lead to highly damaging water heater leaks.

Why the Heater Needs Flushing

Sediment is something that builds up in a water heater tank, and it can't be completely avoided. The sediment comes from the minerals naturally present in the water. In the heated tank, some of these minerals precipitate out of the water and solidify, usually in the form of limescale that coats the inside and bottom of the tank. Over time, the scale flakes off of the tank walls and settles on the bottom.

If your area has hard water, then sedimentation will build up in the tank more rapidly. Over time, this sediment layer reduces the capacity of your water tank as it takes up space water should occupy. This reduced capacity can also make the tank more prone to overheating. Sediment may lead to an increased chance of rust and corrosion as well, increasing the likelihood of a leak.

Signs You Need to Flush

There are several signs that the sediment layer is becoming too thick in the tank. You may hear increased cracking and popping from the tank, which occurs when scale cracks and falls off the tank walls. Your water temperature may also run high, or you may have a reduced amount of hot water when you are running the tap.

Leaks can also be a sign that you need to flush the tank. Leaks may occur at the water line connections on the tank, usually as a result of sediment getting into the lines and causing a blockage. There may also be leaks from the overflow valve at the top of the tank. This is due to overheating in the tank from the reduced water capacity.

The Basic Process

Flushing is a straightforward process that any water heater service can perform. It begins by shutting off the water supply to the tank and allowing the water too cool somewhat. Then, a hose is hooked up to the drain valve at the bottom of the tank. This hose is routed to the nearest drain capable of the water load, or it may be routed outside to a sewer opening.

Once the hose is in place, the valve is opened and the tank is left to drain. Then, the cold water supply is turned on and water is run through the tank and out the drain line so any remaining sediment is flushed out. Finally, the drain hose is disconnected, the valve is closed, and the tank is returned to normal operation.

Contact a water heater contractor if you need more help with routine water heater maintenance.