Step 1 to being Capable - fix your own toilets!
- The Best Life Awaits
- Feb 23
- 6 min read
Updated: 2 days ago
We try to live a simple and practical life. No we're not living off-grid in the woods, or on a boat, or like the Amish. Simple being uncomplicated, unburdened, un-stressed, as much as possible. So when we hear water running constantly it piques our senses. What's leaking? Do we have plumbing problems? Do we need to call a plumber? A little poking around easily finds the source of problem. A little confidence to learn and fix it yourself.
This isn't just about saving some money. You will save for sure. It's about our second and core mantra: Capable. It's not only satisfying to be capable of doing things. It saves money. It builds self-confidence. Maybe most importantly; it builds self-sufficiency. We're not basing our schedule on when a plumber can show up. We get the parts and when it fits our schedule we fix it...Freedom.
We'll show you how to diagnose common toilet issues and determine which part has failed before you start swapping components. In our case, we ended up with two issues on the same toilet. That's how it often goes. You fix one thing and shortly after another breaks. In our case we had three things break: The Fill Valve, the Canister Valve (flapper), and our Toto Bidet all broke within 1 month. Check out our separate post on the bidet.
It may not feel like much. But being able to fix little things around the house is very rewarding and saves money. We live in California and running water can lead to very high water bills. California has many things that are much more expensive then the rest of America: housing, taxes, gas, and yes...water. So being capable of fixing plumbing problems is a valuable skill here!
Let's cover some basics first to help navigate.
Main Parts Inside a Toilet Tank
Most toilets contain these core components:
Fill Valve
Refills the tank after a flush.Located on the left side of the tank and connected to your home’s water supply.
Flush Valve
The central assembly that releases water into the bowl when you flush.
Flapper (or Canister)
The mechanical seal at the bottom of the tank. It holds water in the tank until you flush.(Some models, including ours, use a canister instead of a traditional rubber flapper.)
Float
Controls how much water fills the tank by signaling the fill valve when to shut off.
Overflow Tube
Prevents flooding.If water rises too high, it drains safely into the bowl instead of onto your floor.
Handle / Lever
Activates the flush mechanism.
Tools You May Need
This repair is beginner-friendly.
Possible tools:
Adjustable wrench (for supply line nuts)
Screwdriver (for adjustments)
Utility knife (if replacing supply line)
Bucket (to catch water)
Towels or rags
In our case, everything was hand-tight. We only needed:
Knife
Bucket
Rags
The Two Most Common Toilet Problems
1) Toilet runs continuously 2) Toilet doesn’t flush properly
If your toilet doesn’t flush well, the issue is usually mechanical — a disconnected chain, broken lever, or flush valve linkage. We won't be covering that in this post.
But if your toilet runs constantly, the problem is usually one of three things:
Incorrect water level (float adjustment)
Worn flapper or canister gasket
Faulty fill valve
Step 1: Check the Water Level
Remove the tank lid and look inside.
Is the water level too high and flowing into the overflow tube?
If yes, the issue is likely:
Float adjustment
Failing fill valve
If the water level looks correct but the toilet still runs, you likely have:
A leaking flapper
A bad canister gasket
Step 2: The One-Hour Test
This is the easiest diagnostic step.
Turn off the water supply to the toilet.
Do not flush.
Leave it alone for one hour or more.
Now check the tank:
If the water level is unchanged
The issue is likely float or fill valve related. The canister/flapper and other seals are okay. If they were worn and leaking the water level in the tank would drop. This indicates that the problem is most likely the water coming into tank. The float valve - what turns off the water when tank is full or the fill valve itself.
If the tank has drained significantly
Water is leaking into the bowl or onto your floor!
The problem is almost certainly your flapper, canister, or gasket.
There are only two main exit points for water inside the tank:
Fill valve opening
Flush valve opening (to the bowl)
If the fill valve were leaking externally, you would see water on the floor. No water on the floor? The leak is internal — almost always the flapper or canister seal.
Fixing a Water Level (Float) Issue
If water is overflowing into the overflow tube: Start by adjusting the float.
Adjustment mechanisms vary by model:
Modern toilets often use a vertical float integrated into the fill valve.
Older toilets may have a ball float on a rod.
On ours, the fill valve must be pressed down and rotated to adjust water level.
After adjusting:
Flush partially to lower water level.
Let the tank refill.
Repeat until the water stops about ¼ inch below the overflow tube.
If adjustment does not solve the issue, the fill valve itself is likely failing and should be replaced.
Fixing a Flapper or Canister Leak - our first problem
If your water level looks correct but the tank still drains slowly over time, your seal is failing. In our case, the toilet uses a canister-style flush valve. The gasket between the canister and tank had deteriorated. Water was slipping past the seal and into the bowl — even though the water level was below the overflow tube.
We confirmed this by turning off the water and returning later to find the tank empty.
That tells you the leak is at the bottom of the tank. For this repair, we replaced the canister gasket.(See our step-by-step video here.)
How We Knew the Fill Valve Was Failing - Our second problem
It only took about two weeks and we got another notification from our water company. Looks like something was still leaking. Naturally I assumed that my canister job failed and it was still leaking. So I turned off the water to tank and came back a few hours later. The water level had not dropped. I didn't screw up the canister replacement!
That left two possible culprits:
The fill valve
The float
On our model, those are integrated into one assembly. To adjust the water level on this toilet, you press down on the fill valve and rotate it to raise or lower the float.
We adjusted it several times.
Each time, the water level continued rising until it overflowed into the overflow tube. So several float adjustments failed to fix the issue. That’s a classic sign the fill valve is no longer regulating pressure correctly. At that point, replacement is faster and more reliable than trying to “tune” it. And yes — it often feels like parts fail in sequence. Fix one issue, and the next weakest component gives out.
That’s homeownership.
(Our TOTO Washlet had also recently failed. Apparently it was toilet month.)
Step-by-Step: Replacing the Fill Valve
Turn off the water supply to the toilet (valve at the wall).
Flush the toilet to drain most of the tank.
Place a bucket under the tank, beneath the fill valve connection.
Disconnect the water supply line from the fill valve.
Remove the nut securing the fill valve to the bottom of the tank.
Disconnect the small refill tube from the overflow pipe.
Remove the old fill valve and catch any remaining water.
Insert the new fill valve.
Reattach the securing nut (hand-tight, then slight snug).
Reconnect the supply line.
Turn water back on and adjust water level as needed.
That’s it.
Total time: about 20–30 minutes.
When to Replace Instead of Adjust
Replace the fill valve if:
Water continuously runs into the overflow tube
The tank never stops filling
Adjustments don’t stabilize the water level
The valve is more than 5–7 years old
Fill valves are inexpensive and considered wear items.
Final Thoughts
Toilet repairs look intimidating — but most internal tank components are modular and designed for easy replacement.
If you’ve already replaced a flapper or canister gasket, this is the natural next step in troubleshooting.
And once you’ve done it once, it becomes a 15-minute job the next time.
Homeownership isn’t about avoiding failures.
It’s about knowing how to fix them when they happen.
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