How to Adjust the Water Level in Your Toilet

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If you’re wondering why anyone would even need to know how to adjust the water level in their toilet, then chances are your water level is perfect. But some toilets tend to overflow while others barely fill up at all.

Professional plumbers can be expensive and some people are on a budget, which leads many to try DIY (do-it-yourself) methods. If possible, read the instruction manual that came with your toilet or go to the manufacturer’s website for tips. Familiarize yourself with the parts inside your toilet tank before making any changes. 

Recommended Read: Best Small Toilets Reviewed For Compact Spaces

What can cause too little or too much water in the toilet?

Toilet overflow can be caused by clogged pipes, blocked vents, sewage issues, or a full septic tank. The opposite problem—low water level—can be caused by a damage fill tube or valve, a sewer vent line issue, or even a cracked bowl (which you’d need to replace). 

For issues stemming far from the toilet itself (such as: a dead animal blocking the flow from the main sewer system), you will have to call in a pro. But if it is a minor issue, you can breathe a sigh of relief. Adjusting the water level in your toilet is not as difficult as you might think.

Toilet tank vs Toilet bowl

The tank is the upper part of the toilet that contains the flushing mechanism in a small water reservoir. The tank contains the mechanisms needed for the toilet to function: fill valve, flush valve, overflow tube, rubber flapper. The bowl is the round vessel that is open at the top and holds the waste before it is flushed away. 

Recommended Read: The Best Toilet Padded Toilets Seats for a Comfortable Sit

Ways to adjust water in toilet 

Method 1: Unclog Pipes

Old rusted pipes of a toilet

When your water level is too high, clogged pipes are a common reason. This means the water is not draining away as it should; some stays in the bowl, while the tank fills it with more. 

What you will need: Bucket, rubber gloves, toilet plunger, (possibly) store-bought toilet un-clogger.

What to do: first, do a test to determine if there is a blockage. Fill a bucket with water and pour it into the toilet bowl. If the excess water does not drain out through the bottom of the bowl, then you likely have a jammed pipe. 

Put on your gloves and feel for something just below the surface of the drain that could be the cause (wadded toilet paper, tampon, or even your pet’s favorite toy). 

Recommended Read: The Best Short Depth Toilets 24-25in or Less

If there no immediate results, then move onto a plunger. Place the cup of the toilet plunger over the drain to ensure a tight seal and, using firm pressure, push and pull the plunger vertically with concentrated thrusts for 30 seconds without lifting the plunger from the drain and breaking the seal.

If the plunger doesn’t do the trick, try pouring boiling water into your toilet or using over-the-counter chemical products to unblock it.

Method 2: Adjusting a Cylinder Float 

Parts of a toilet broken down in a graphic image
Source

When your water level is too high or too low, the culprit in both cases could well be a maladjusted cylinder float. 

What you will need: Rubber gloves.

What to do

1. Put on your rubber gloves. Remove the lid from the toilet tank. Be careful, as these are usually made of ceramic, which breaks easily.

2. Check the water level. If it is higher or lower than 1 or 2 inches below the fill valve and overflow tube, it could need a modification.

3. Identify the cylinder float. Newer toilets may be equipped with modern one-piece floats instead of the older ball-and-arm design. These updated floats are solid cylinders fitted to the shaft of the fill valve itself. 

4. Turn off the water. Find the external water valve on the wall (it should be behind your toilet, beneath the bowl). Turn the knob clockwise as far as it will go. When it won’t go anymore, flush the toilet and keep on flushing it until the tank is empty.

5. Look for the adjustment stem, which is a long, thin tube that connects to the fill valve. With that, raise or lower the float 1⁄2 inch. Twist the stem with your fingers clockwise or counterclockwise a full rotation (clockwise to lower the height or counterclockwise to raise it). Once you’ve adjusted the float, replace the toilet lid, and turn the water valve back on.

6. Wait for the toilet tank and bowl to fill, then flush to see if the level has improved. 

Recommended Read: Best Toilet Repair Kits That Fit Almost Any Toilet

Method 3: Adjusting a Ball-and-Arm Float 

When your water level is too high or too low, the problem might stem from a ball-and-arm float that has gone off its factory adjustment. 

What you will need: Rubber gloves, screwdriver.

What to do

1. Put on your rubber gloves. Remove the lid from the toilet tank. Be careful, as these are usually made of ceramic, which breaks easily.

2. Check the water level. Same as with the more modern cylinder float, if the water is higher or lower than 1 or 2 inches below the fill valve and overflow tube, it could need an adjustment.

3. Turn off the water as outlined in method one and empty the water from the toilet by flushing it as many times as needed.

4. Inspect the ball and arm. Are they corroded or cracked? If so, they will need to be replaced. If not, then proceed to the next step. 

5. Adjust the height of the float using a screwdriver (the screw is usually located directly above the fill valve). Clockwise or counterclockwise turning will lower or boost the height of the float. Keep the full rotation to one. More turns of the screw could cause inconsistent flushing of the toilet. Once you’ve made your adjustments, replace the toilet lid, and turn the water valve back on.

6. Wait for the toilet tank and bowl to fill, then flush to see if the level has improved. 

If none of the above 3 methods work, you will have to call a plumber. 

Method 4: Installing a New Fill Valve 

Opened toilet tank with fill valve highlighting
Source

If your fill valve has quit working, you can replace it yourself. Even a beginner can do it, and it only takes about 90 minutes. When you buy a new fill valve, it should have installation instructions with it.

What you will need: Rubber gloves, new fill valve, adjustable pliers, or an adjustable wrench.

What to do

1. Put on your rubber gloves. Remove the lid from the toilet tank. Be careful, as these are usually made of ceramic, which breaks easily.

2. Turn off the water supply from the wall pipe to the toilet. Empty the water from the toilet by flushing it as many times as needed.

3. If you’d like, remove the refill tube from the overflow pipe holder and unhook the flapper chain from the flush lever to make space. You can leave these things in situ, but it’ll be more crowded inside the tank. 

4. Using your adjustable pliers or an adjustable wrench, remove the valve nut. Remove and lift the fill valve from the tank. 

5. Place the valve shank onto the fill valve. Insert the fill valve base into the tank opening, then

push down on the valve shank. Tighten the locknut as much as possible to seal the valve.

6. Reconnect the supply line to seal the flow of water. Inside the tank, reattach the refill tube and angle the adaptor to the overflow pipe holder. Replace lid.

7. Turn on and adjust the water supply to flush your toilet and test the installation.

Conclusion

What do you think? Are the above methods easy and worth trying, or will you be making an appointment with the nearest plumbing professional? Let us know in the comments below. 

White toilet in bathroom

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