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When something’s wrong, toilet pipes can make a cacophony of sounds after being flushed. Specific noises let you know which part of your toilet or plumbing pipe is failing and in need of replacement or adjustment. From banging and hissing to bubbling and beyond, here’s how to know what’s broken and how to fix it.
1. Banging Pipes
If you hear a banging or a bumping noise coming from your pipes after you flush the toilet, you likely have a water hammer issue on your hands. This shockwave effect occurs after a sudden change in water pressure, causing the pressurized water to bang against the valve opening. If not fixed promptly, a water hammer can create major plumbing problems.
Water hammers are often caused by the following problems.
- Soaked air chambers: Air chambers cushion pipes and absorb the sound wave effect that happens when water flow comes to a sudden stop. When air chambers become waterlogged they can no longer protect the pipes from the change in pressure from slamming against the interior of the pipes. This can cause significant damage.
- Loose mounting straps: Mounting straps secure pipes from changes in water pressure. When the straps become loose, it’s not unusual to hear banging pipes.
- Closing valves: When upstream valves close and the water flowing downstream continues to run, a vacuum effect can occur. This vacuum can cause the pipe to bust or collapse.
How to Fix It
- Tighten pipe mounting straps or replace them to hold the pipes in place.
- Install a water hammer arrestor to help minimize the shockwave in a toilet or water heater. The arrestor, a more permanent fix, will need to be soldered in place, so consider hiring a licensed plumber if you’re not good at soldering.
- Cushion shockwaves with new air chambers. First, you’ll need to turn off your main water valve and drain your pipes. Keep two faucets open before you reopen the main water valve and refill the pipes with new air chambers.
2. Hissing Toilet
A hissing sound that occurs after you flush can indicate various toilet repair issues such as leaks. This typically happens in older homes. Let’s take a closer look at some potential reasons for the hiss.
- High water level running from flow water lines to the toilet
- Corroding rubber flapper or an excess of sediment covering the flapper or valve seal is causing a leak.
- The toilet lift chain connecting the lever to the flapper creates an air or water leak or prevents the flapper from working properly.
How to Fix It
- Set the fill valve and the float below the water fill line to keep water from rising too high and continually draining into the overflow tube.
- Replace the flapper if the rubber has worn. If you have sediment buildup in the tank, remove it so the flapper can properly create a watertight seal over the flush tube located at the bottom of the tank.
- Check the fill valve seal at the top of the tank for sediment buildup. Remove the buildup and listen for hissing. Installing an effective whole house water filter can minimize the accumulation of sediment in all your appliances.
- If you still hear hissing after you’ve attempted these fixes, contact a licensed plumber.
3. Bubbling or Running Water
If you hear the sound of bubbling or running water, and your toilet bowl continues to fill, your toilet has probably sprung a leak. A leak can waste a lot of water and run up your bill. You likely have one of the following issues.
- The fill valve is defective.
- The toilet lift chain connecting the lever to the flapper is too tight.
- The setting of the float in the tank is too high.
How to Fix It
- Remove the tank lid and examine the fill valve level. If the float is higher than the fill valve, it’s an easy fix. Just adjust it to resolve the problem.
- If that doesn’t fix the issue, check the tightness of the chain. If the chain is too snug, it can prevent the flapper from a proper seal. Detach the chain and adjust the length by rehooking the chain to a link that makes the chain longer. Make sure the chain isn’t tangled or twisted.
- If adjusting the float water level or the toilet lift chain doesn’t stop the bubbling or running water noise after you flush the toilet, call a local plumber.
4. Rushing Water
Water pressure is measured by PSI or “pounds per square inch.” PSI refers to the force of the water that travels from the main line and into the pipes in your home. The average PSI for household pipes should fall between 30 to 80 PSI. However, the water pressure should never be higher than 60 PSI, or it can harm your plumbing fixtures. If you hear rushing water in your toilet, high water pressure is likely the issue.
How to Fix It
- You can determine if you have a high water pressure with a water pressure gauge. These gadgets are inexpensive and can be purchased at Home Depot, Lowes and other home improvement stores for $10 to $70, depending on whether the gauge is made from plastic or heavy-duty metal.
- Connect the gauge to a hose bib to learn the PSI reading. If the pressure level is higher than 60 PSI, you’ve found what’s causing the sound of rushing water when flushing the toilet.
- You’ll need to install a pressure regulator where the water enters your house to regulate your water pressure level. If you install the regulator yourself, make sure to turn off the main water line first.
5. Self-Flushing Toilet
If your toilet starts flushing itself, you can bet the usual suspect is a faulty flapper. This self-flushing noise occurs when the flapper loses its airtight seal, allowing water to slowly but surely leak into the bowl from the tank. This action switches the water back on causing your toilet to flush itself.
How to Fix It
- You can diagnose and remedy a faulty flapper in minutes.
- Place a dye tablet or a teaspoon of food coloring in your toilet tank and wait 15 minutes. If you see color in the toilet bowl, you’ll need a new flapper.
