Imagine going about your daily routine when you suddenly hear a loud, banging noise coming from your water pipes. It’s enough to make you stop what you’re doing to investigate what happened. What you just experienced is something known in the plumbing industry as ‘water hammer’.
Water hammer is more than just a surprisingly loud noise. It’s an indication that water flowing through your pipes was suddenly forced to stop or change direction. An occasional water hammer you don’t hear again for months or years is no cause for concern. But if it happens a lot, it is time to call a plumber.
A Shocking Situation
Utah’s Beehive Plumbing explains that water hammer is also known as hydraulic shock. This secondary name gives a good indication of what’s going on when the phenomenon occurs. Water hammer is all about moving water and kinetic energy.
As water moves through the pipes, it is under pressure. Both natural movement and pressure create kinetic energy. If that water is forced to suddenly stop or change directions, some of the kinetic energy flows into the pipes. It needs to go somewhere, right?
The result of that energy movement is a shock wave that travels through pipes, fittings, and fixtures. If the shockwave is strong enough, it creates vibrations and a loud bang. An especially severe shock can even cause pipes and fittings to burst.
What Causes Water Hammer
So, what actually causes water hammer? Beehive Plumbing says there are plenty of potential causes. Here are some of the more common causes they see:
- Valve Closure – Fast valve closure is a typical culprit. In a commercial setting, plumbers could be looking at faulty valves. In a residential setting, appliances like dishwashers and washing machines can cause water hammer when their shut off valves close too quickly.
- Solenoid Valves – Speaking of dishwashers and washing machines, they often utilize solenoid valves to quickly stop water flow. Solenoid valves are a common cause of water hammer in residential scenarios.
- Water Pressure – Water pressure below 55 psi is generally recommended for homes and small businesses. Higher pressures can contribute to water hammer because water is moving so forcefully through pipes.
- Loose Pipes – Loose pipes, especially when assembled in long runs, can contribute to water hammer due to being insecure. Rather than shock energy being transferred to support structures, it continues along the loose pipes.
Pump shutdowns, trapped air, and other things can cause or contribute to water hammer. As previously stated, persistent water hammer is something to be concerned about.
How Plumbers Address It
Bringing in a plumber to address water hammer is one way to solve the problem for good. A common tactic plumbers rely on is installing water hammer arresters. These are small devices that absorb shock waves, thereby preventing the energy from flowing further up the line. Arresters are especially effective at preventing solenoid valve-related water hammer.
A plumber might also:
- Check and adjust water pressure.
- Secure loose pipes.
- Check and clear venting.
- Replace worn out valves or washers.
- Adjust valves so they close more slowly.
- Install reinforcement plates.
Water hammer can occur in both residential and commercial settings. It’s more likely to be severe in a commercial setting due to larger and more complex plumbing systems.
Fortunately, the root causes of water hammer are pretty easily identified. Solutions are effective as well. So there really is no reason to ignore water hammer if it’s occurring on a regular basis. Getting it taken care of will not only stop the surprisingly loud noises, but it will also minimize the risk of damage.
