The Quick Fix for a Weak Toilet Flush
Are you tired of your toilet’s weak flush? A weak flush can be frustrating and inconvenient, but luckily, it’s often a problem that can be easily fixed. I’ve encountered this exact problem hundreds of times over the last 10 years when I worked in maintenance at a property with over 250 toilets. In this quick article, we’ll explore the reasons behind a weak toilet flush and what you can do to fix it. Let’s get started!
What Causes a Weak Toilet Flush?
There are three primary causes for a weak toilet flush:
- A clogged toilet trap
- An obstructed vent pipe
- Malfunctioning flush valve
- A problem with the Flapper Chain
Clogged Trap
The first common reason is a clogged toilet trap. The toilet trap is the S-shaped pipe that connects the toilet bowl to the drain pipe. When this pipe gets clogged with waste or other debris, it can restrict the flow of water and cause a weak flush.
A common blockage from when I worked maintenance was people flushing used bars of soap. I don’t know why they did it, but they would lodge themselves in the S-shaped pipe and act as a flap as they would rock back and forth on the bends in the “S”. This blockage would need to be cleared with a snake or would last until the soap slowly dissolved with each weak flush. More on how to fix this later.
Obstructed Vent Pipe
The second common reason for a weak flush could be a blocked or obstructed vent pipe. The vent pipe is a vertical pipe that connects to the toilet drain line and extends up through the roof. Its purpose is to allow air into the drain system to facilitate proper flushing. If this pipe becomes blocked or obstructed, it can restrict the flow of air and cause a weak flush.
Unfortunately, you’ll need to climb on your roof for this fix to see if birds, insects, or a squirrel have taken a liking to your vent pipe. If heights are an issue for you, and I recommend ruling out the other possibilities first or before calling a professional.
Malfunctioning Flush Valve
A third possible cause of a weak flush is a malfunctioning flush valve. The flush valve is the mechanism that releases water from the tank into the bowl when you flush. If this valve is not functioning properly, it can cause a weak flush.
Flapper Chain not Configured Properly
A fourth possible reason for a weak toilet flush is if your chain that leads from the flushing handle to the flapper isn’t set correctly. If it’s got too much slack, it may not fully lift the flapper to allow the proper amount of water to rush down into the bowl.
How to Fix a Toilet with a Weak Flush
Now that we know what causes a weak flush, let’s talk about how to fix it.
The first step is to check the toilet trap for any clogs. This can be done using a plunger, auger, or a plumbing snake. You can buy the smaller 6′ augers or longer wind-up snakes from Amazon or your local hardware store.
Pro Tip: If you leave unsightly scuffs and scratch marks inside your toilet bowl from using a toilet auger or snake, turn off the water to the toilet, drain the reservoir by flushing, and then use a wet/dry shop vac to remove the water from the bowl. Then use Barkeepers Friend cleaning powder and a paper towel to scrub the scratches. Your porcelain will look like new again!
If the clog is particularly stubborn, you may need to remove the toilet from the floor and clean out the trap manually. Not a fun job, but somebody’s gotta do it!
You will also want to verify that the chain that leads from the flush handle to the flapper isn’t too loose. Remove the lid to the reservoir and watch the flapper as you flush. If it barely lifts up, tighten the chain a few links and repeat until the flapper stays up for about 5 seconds after you flush until it drops back down to seal the reservoir.
Next, check the vent pipe to make sure it is not obstructed. This can be done by climbing up on the roof and inspecting the pipe. If you are unable to access the roof, you may need to call in a professional to check the vent pipe for you.
If neither of these solutions work, the problem may be with the flush valve. To fix a malfunctioning flush valve, you will need to replace it. This is a relatively simple process that can be done with a few basic tools. Start by turning off the water supply to the toilet and flushing the toilet to empty the tank. Remove the old flush valve and replace it with the new one, following the manufacturer’s instructions.
If you are still experiencing a weak flush after trying these solutions, there may be a more serious problem with your plumbing system. In this case, it is best to call in a professional plumber or handyman to diagnose and fix the issue.
How to Prevent a Weak Toilet Flush
In addition to these troubleshooting steps, there are a few preventative measures you can take to avoid a weak flush in the future.
Do not do flush the following:
- Wet Wipes (even the ones that say you can!)
- Feminine Hygiene Products
- Paper Towels
- Condoms
- Bars of Soap (yes, when I did maintenance this would happen more than you might believe)
- Socks, Wash Rags, or other Pieces of Clothing
One simple step is to avoid flushing non-flushable items down the toilet. This includes items like wet wipes, feminine hygiene products, and paper towels, condoms, or bars of soap. These items can easily clog the toilet trap and cause a weak flush.
Only flush human waste and toilet paper if you want to stay out of trouble!
Another preventative measure is to keep your toilet clean. Regular cleaning can help prevent buildup of waste and debris in the toilet trap, which can lead to a weak flush. Use a toilet bowl cleaner and scrub the inside of the bowl regularly.
A weak flush can be a frustrating problem, but it is often easily fixed. By checking for clogs, inspecting the vent pipe, and replacing a malfunctioning flush valve, you can restore your toilet’s flushing power. Taking preventative measures like avoiding flushing non-flushable items and keeping your toilet clean can also help prevent a weak flush in the future. If you are unable to fix the problem on your own, don’t hesitate to call in a professional plumber for assistance.
