Tell me if this sounds familiar – you are sleeping comfortably and in the middle of the night a soft but persistent knock sounds through the pipes in your home. At first it is easy to ignore, but inevitably the sound will grow with each passing night and eventually start keeping you awake. Luckily, there are simple solutions for knocking pipes that do not require a plumber or expensive parts.
First, it is good to know why your pipes are knocking in the first place. In most cases, knocking pipes are caused by variable water pressure in the main supply pipes coming into your home. That pressure is important because it keeps the water moving freely between pipes and into your faucets. However, when the air used in pressurizing those pipes leaks or is depleted, water moves suddenly and violently, creating the knocking sound as it traverses the length of the supply lines.
The easiest fix for this kind of knocking is to first turn off your main supply valve. Make sure you communicate to anyone in your home that you are shutting off the valve as it will stop ALL water coming in. Now, flush the lines by opening all of the faucets and flushing your toilets. Water can still leave your home through drainage pipes and this will ensure all of the supply lines are fully empty.
Once the lines are cleared, feel free to turn your main valve back on. It is important to do this slowly so that the air chambers between and around your pipes have time to refill before the water courses back into them. However, now that the pipes were fully emptied, the knocking sound should be completely gone.
It is as simple as that. In most cases, you should not need to call a plumber to help, but if you have any problems finding your main valve or shutting it off, a plumber can be helpful with the proper tools and the knowhow for various kinds of shutoff valves. Additionally, if you live in an apartment building or a shared space, you may not be able to perform this fix. Rather, you should contact your superintendent or landlord and make sure they know exactly what is happening – with any experience, they should recognize the problem and be able to make similar fixes to your pipes.
Knocking pipes can be incredibly frustrating if not dealt with as soon as they start. Now that you know how simple it is to make the fix, make a habit of regularly flushing your lines and the knocking likely will not start up again.