Fixing my leaking shower

Is Sediment Causing Low Hot Water Pressure Problems?

by Andy Butler

If the hot water supply in your home has been reduced to a dribble, your hot water system probably isn't generating enough water pressure. Sediment buildup inside your hot water system is one of the most frequent causes of low hot water pressure, and can also cause other, more serious problems with your system. 

How Does Sediment Reduce Hot Water Pressure?

The water that comes from your taps and showers contains a variety of minerals and other dissolved solid substances. The exact composition of these solids will vary depending on where you live, but in most areas, tap water contains a significant amount of dissolved calcium and magnesium.

When water is heated as it passes through your home's hot water system, a small amount of the water will evaporate. The minerals that were dissolved in the evaporated water are left behind, forming solidified sediment that accumulates on solid surfaces and inside hot water pipes. Over time, these sediment deposits will grow.

Once too much sediment accumulates inside the hot water system, it can start to block pipes and other critical components, such as heat exchangers. If your hot water system has a storage tank, sediment buildup will also reduce the tank's overall capacity. Both of these problems can significantly reduce hot water pressure, preventing enough hot water from reaching your taps and showers when you need it most.

Does Sediment Buildup Cause Other Problems? 

If sediment buildup is causing issues with your hot water pressure, you may also notice other problems with your hot water system. The reduced flow of hot water may fluctuate in temperature since the sediment deposits cause it to pass through the heating system at an inconsistent rate.

You may also notice that the hot water coming from your taps and showers is discoloured, and has an unpleasant, metallic smell and taste. In extreme cases, the hot water system may start making rumbling and/or popping noises while it is functioning. This is a serious problem caused by water boiling inside the system's heat exchanger and can damage your system if the sediment is not removed.

What Should You Do About Hot Water System Sediment?

Sediment problems inside your hot water system can usually be solved by draining the system and flushing it with fresh water. If you know your way around a water heater, you can do this yourself by opening the water heater's drain valve. Most water heaters should be flushed once or twice a year to prevent sediment problems.

However, if enough sediment has accumulated inside your system to reduce your hot water pressure, trying to flush the system yourself can be difficult, and flushing out such a large quantity of sediment can cause damage to some of your system's components. In these circumstances, it is generally safer to call in plumbers specialising in hot water repair to do the job for you.