Check with a plumber to determine if it’s a minor cause or immediate safety concern
Compiled by Sarah Gray/Managing Editor
You notice that the usually quiet hot water tank is now hissing, and it does not stop. Is that normal or is it a sign of something serious?
The hot water tank is the large container that heats and stores water for use in your home. Water enters the tank from your home’s main water supply and is heated by either natural gas or electricity.
There are several things that could cause your hot water tank to hiss. But a good rule of thumb is if it is concerning you, have a professional plumber look at it.
According to the Water Wise Plumbing website, “Whether a hissing water heater is dangerous or not depends on the underlying cause. A range of reasons can make a water heater hiss. While some may indicate a substantial problem requiring immediate water heater repair or replacement by a professional plumber, others are not severe enough to cause any concern and may only need a quick fix.”
One of the most common reasons your water heater may be hissing is the pressure relief valve doing its job – releasing built up pressure in the tank. If this is the case, the hissing will stop when the pressure is at a sustainable level. The pressure is often caused by either too much sediment buildup or the thermostat being set too high.
Sediment inside the tank is something that builds up over time due to the accumulation of mineral deposits. That slows down the transfer of heat, creating more pressure, and it could be time to have this cleaned out.
Oftentimes the thermostat is set too high. Homeowners can turn down the temperature to see if this stops the hissing. A safe temperature is around 120 degrees F. If it is up to 140 degrees, that could create a dangerous situation.
A pressure relief value, though, can also be faulty and leak at normal temperatures. Look around the valve to ensure it is set properly and that you do not see any cracks.
A minor cause for hissing is simply condensation, according to Water Wise Plumbing. Condensation builds up when a large amount of hot water is used in a short period of time, such as with a long shower. When the tank empties and begins to refill with cold water, condensation can accumulate on the outside and come into contact with hot parts of the appliance, creating the hissing sound, which should dissipate after a short amount of time.
Another possibility is that there is a crack inside the tank. Homeowners can check around the base of the tank for puddles. A small amount of puddling does not typically indicate that a leak is large enough for immediate attention; however, the problem could get worse over time. If large amounts of water are pooling around the floor, call a plumber right away.
Get to know your hot water heater. It provides your home with hot water for daily use, such as warm showers, doing laundry and dishwashing. If it is hissing continually or repeatedly throughout the week, call a plumber for a thorough inspection. While minor hissing is simply an odd sound because you don’t often hear it, a continual hissing could be a sign of a bigger issue. For your peace of mind, have it checked by a plumber or flushed out.
