It can be quite disconcerting to hear your toilet flush or run your washer and hear the banging sound in your walls. Water hammer is a problem that can cause a lot of problems. We will examine the causes and how to fix it.
Consider a train. The train churns along at maximum speed until suddenly, a boulder falls onto its tracks. Every train car crashes into the other as the train collides with it. This causes a lot of chaos and disruption. It’s not as dramatic but it can happen inside pipes that have pressure irregularities. When you flush the toilet, water will quickly rush through the pipes. Anything that hits your wall can cause damage after the toilet has finished filling. It is crucial to fix the water hammer. The way your home was built and the time it was built will determine how to fix it.
Homes built before 1960 likely had air chambers to prevent water hammer. Air chambers are pipes that connect to main water pipes by using a T fitting, which is then capped at its top. The pipe is capped with air. This acts as a buffer and absorbs shock. This air chamber is analogous to an engine compartment. It acts as a switch on the tracks that allows the train driver to safely stop and avoid the boulder. This system isn’t foolproof, as the air chambers could eventually become filled with water. They can become ineffective and could cause water hammer. There is an easy fix. You only need to shut off the water supply to your home and drain the water from all pipes. To flush all toilets, turn on every faucet, and run the dishwasher and washer, you will need to open them all. Turn off your water supply.
Your home may not have any or very limited water hammer protection if it was built between 1960-1990. A professional plumber may install water hammer arrestors to protect your home. It’s not a problem because most homes have water hammer arrestors installed after 1990. It is a small, spring-loaded shock absorber. It diverts water force from the valve or faucet when it is closed to reduce water hammer. An arrestor has the advantage that it does not become clogged like an old-fashioned air chamber. Installing your arrestors will require a plumber, but they should be able to reduce the banging sounds.