No water enters the tank at all
You flush, the tank empties, and then nothing happens. You do not hear the usual refill sound.
Start here: Start with the shutoff valve position and the toilet supply line, then move to the toilet fill valve.
Toilet troubleshooting
Toilet Not Filling
Direct answer: If a toilet is not filling, the problem is usually at the water supply to the tank or inside the tank at the toilet fill valve. Start by making sure the shutoff valve is fully open and the supply line is not kinked, then check whether the fill valve float is stuck or the inlet is packed with grit.
Most likely: The most common cause is a toilet fill valve that is stuck shut or clogged with sediment after the water was turned off, plumbing work was done, or an older valve finally quit moving freely.
First separate no water at all from slow refill and from a tank that fills but the bowl still looks wrong. That keeps you from chasing the wrong part. Reality check: most no-fill toilets are fixed at the shutoff, supply line, or fill valve. Common wrong move: buying a whole toilet when a $15 to $30 tank part is the real issue.
Don’t start with: Do not start by replacing the flapper or assuming the drain is clogged. A toilet that will not refill is usually a tank-side water supply problem, not a bowl-side problem.
No refill after a flush?Check the shutoff valve and supply line before opening the tank parts list.
Tank fills slowly or stops halfway?Look for a stuck float or a clogged toilet fill valve inlet.
Last reviewed: 2026-04-04
What the toilet is doing
Tank refills very slowly
Water trickles into the tank or takes several minutes to refill.
Start here: Look for a partly closed shutoff valve, a kinked toilet supply line, or sediment clogging the toilet fill valve inlet.
Tank starts filling then stops early
The tank gets some water but quits before normal level, or jiggling the float makes it start again.
Start here: Check whether the toilet fill valve float is hanging up or the valve body is sticking.
Tank fills but bowl water still looks low or odd
The tank reaches level, but the bowl does not refill to its usual resting level after the flush.
Start here: That points away from a no-fill problem and more toward bowl refill routing or a drain issue. If the bowl drains slowly, go to /toilet-bowl-drains-slowly.html.
Most likely causes
1. Shutoff valve partly closed or closed
This is common after cleaning behind the toilet, recent plumbing work, or someone brushing the valve by accident. A toilet with no refill sound at all often starts here.
Quick check: Turn the toilet shutoff valve counterclockwise until it stops gently, then flush again.
2. Toilet supply line kinked or blocked
A bent braided line or debris from older piping can starve the tank even when the shutoff is open.
Quick check: Look for a sharp bend in the toilet supply line and feel whether the line is under tension or pinched against the wall or tank.
3. Toilet fill valve stuck or clogged
This is the most likely tank-side failure when the toilet suddenly stops filling or only trickles in. Mineral grit and worn internal seals are common on older valves.
Quick check: Remove the tank lid and see whether the float is stuck high, rubbing the tank wall, or whether lifting and lowering it changes the water flow.
4. Low water pressure only at this fixture or debris at the valve inlet
If other fixtures work normally but this toilet barely fills, the restriction is often right at the toilet shutoff or fill valve inlet.
Quick check: Compare pressure at a nearby sink, then listen for a weak hiss at the toilet while the tank tries to refill.
Step-by-step fix
Step 1: Make sure the toilet is actually getting water
A toilet cannot refill if the shutoff is closed, partly closed, or the supply line is pinched. This is the fastest check and the least destructive.
- Look behind or beside the toilet and find the toilet shutoff valve at the wall or floor.
- Turn the toilet shutoff valve counterclockwise until it stops gently. Do not force an old stiff valve.
- Check the toilet supply line for a sharp kink, twist, or spot where the tank is pressing on it.
- Flush the toilet and listen for refill sound right away.
Next move: If the tank refills normally now, the problem was a closed valve or restricted toilet supply line. If there is still no refill or only a weak trickle, move to the tank and check the toilet fill valve and float.
What to conclude: You have ruled out the simplest supply-side mistake and narrowed the problem to a restriction or failed tank fill component.
Stop if:
- The shutoff valve starts leaking around the stem or packing nut.
- The valve handle feels like it may snap.
- You see water dripping at the toilet supply line connection.
Step 2: Check the float and refill action inside the tank
A stuck float can hold the toilet fill valve closed even when water is available. This is common after the lid was bumped or parts shifted slightly.
- Remove the tank lid and set it somewhere safe.
- Flush the toilet and watch the toilet fill valve as the water level drops.
- See whether the float cup or float arm moves down freely or hangs up on the tank wall, trip lever arm, or refill tube.
- Gently lower and raise the float by hand to see whether water starts, stops, or sputters.
Next move: If moving the float starts the refill and it keeps working after you free it up, the float was hanging up or slightly misadjusted. If the float moves but little or no water enters, the toilet fill valve is likely clogged or failing internally.
What to conclude: A float that sticks points to a simple alignment issue or a worn toilet fill valve. A free-moving float with no refill points more strongly to a blocked or failed valve.
Step 3: Clear debris from the toilet fill valve inlet if the valve only trickles
Sediment often lodges in the fill valve after water service is interrupted. Cleaning the inlet can restore normal flow without replacing parts.
- Shut off the toilet shutoff valve.
- Place a towel under the toilet supply line connection at the tank.
- Disconnect the toilet supply line from the bottom of the tank fill valve.
- Inspect the fill valve inlet screen or opening for grit, rust flakes, or mineral buildup.
- Rinse loose debris away with clean water and wipe the inlet gently. Do not jam metal tools into the valve body.
- Reconnect the toilet supply line, open the shutoff valve slowly, and test the refill.
Next move: If the tank now fills at normal speed, the valve was restricted by debris and does not need replacement yet. If flow is still weak or the valve will not open reliably, plan on replacing the toilet fill valve.
Step 4: Replace the toilet fill valve when it sticks, will not open, or keeps clogging
Once the toilet fill valve is sticking internally or the inlet keeps plugging, replacement is usually faster and more reliable than trying to nurse it along.
- Shut off the toilet shutoff valve and flush to empty most of the tank.
- Sponge or towel out the remaining water near the bottom of the tank if needed.
- Disconnect the toilet supply line from the old toilet fill valve.
- Remove the retaining nut under the tank and lift out the old toilet fill valve.
- Install the new toilet fill valve at the correct height, reconnect the refill tube to the overflow tube, and reconnect the toilet supply line.
- Turn water back on slowly and adjust the water level to the marked line inside the tank if present.
Next move: If the tank refills promptly and stops at the proper level, the repair is complete. If a new fill valve still gets little or no water, the restriction is likely at the toilet shutoff valve or toilet supply line rather than inside the tank.
Step 5: Finish with the right next move if the tank fills but the toilet still acts wrong
Once the tank is refilling normally, any remaining problem is usually a different symptom and needs a different fix.
- Flush the toilet several times and confirm the tank refills to the same level each time.
- Check that the refill tube sends some water into the overflow tube during refill.
- If the tank fills but the bowl drains slowly or the bowl water ends up low, go to /toilet-bowl-drains-slowly.html.
- If the bowl rises too high during or after a flush, go to /toilet-bowl-fills-too-high.html.
- If water appears around the base or under the tank during testing, go to /leak-only-when-toilet-flushes.html or stop and inspect for an active leak.
A good result: If the tank refills normally and the bowl returns to its usual level, you are done.
If not: If the refill is fixed but flushing, bowl level, or leaking problems remain, treat those as separate symptoms instead of replacing more tank parts blindly.
What to conclude: You have either completed the repair or narrowed the issue to the exact next problem instead of guessing at more toilet parts.
Replacement Parts
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FAQ
Why did my toilet stop filling all of a sudden?
Most sudden no-fill problems come from a shutoff valve that is not fully open, debris lodged in the toilet fill valve after water service was interrupted, or a fill valve that finally stuck shut.
Can a bad flapper cause a toilet not to fill?
Usually no. A bad toilet flapper more often causes running or repeated refilling. If the tank is not getting water back in at all, start with the shutoff valve, supply line, and toilet fill valve.
Why does my toilet only refill if I jiggle the float?
That usually means the toilet fill valve is sticking or the float is rubbing on something in the tank. If freeing it up only helps briefly, replace the toilet fill valve.
Should I replace the toilet supply line when I replace the fill valve?
Only if the toilet supply line is kinked, corroded, leaking, or old enough that it may not reseal well after removal. If it is in good shape, you usually do not need to replace it.
The tank fills, but the bowl water is still low. Is that the same problem?
Not always. If the tank refills normally, the no-fill problem is solved. A low bowl level after that usually points to refill tube routing, bowl siphoning, or a drain issue. If the bowl drains slowly, use /toilet-bowl-drains-slowly.html.
How long should a toilet tank take to refill?
Most toilets refill in well under a minute. If yours takes several minutes, treat that as a restriction or weak fill valve problem even if it eventually gets there.