Why is the water in my toilet tank low

Do you know most homeowners panic to think that- the toilet issue can’t be solved without a plumber? For example, why is the water in your toilet tank low- you don’t need an expert to know this reason. Right? 

Toilet tank made with several components that aid in the flushing of a toilet and increase the flushing power as well. 

There are several yet easy-to-understand reasons for low water in the toilet tank.

Why is The Water in My Toilet Tank Low

The water level in the toilet tank depends on various factors, including

  • Adjustable Float ball/Ballcock
  • Refill valve
  • Fill Tube
  • Water Supply Connection
  • Overflow tube and
  • Flapper

Why does Water in Toilet Tank Get Low Due to Adjustable Float ball/Ballcock or Floating Cup

The floating ball or ballcock is a black color rubber ball attached to the fill tube. This floating ball is the first tool that determines the water level in the toilet tank.

In the older style toilet mainly carry floating ball. The modern one has a floating Cup top of the fill valve.

It has a metal arm that looks like a rod, or in a new toilet, a floating cup is present instead of the floating ball.

Lower the floating ball or cup, a lower level of water exists in the toilet tank. A low water level in the tank results in a slow flushing toilet.

Check the floating ball or cup level. It is too low. By adjusting the height, you are able to increase the water height in the tank.

To fix this issue

  • Open the tank lid
  • bend the floating arm upwards direction
  • Or if you see any screw present on top of the fill valve, half turn it clockwise. It will help to move the height upward direction.
  • Flush once and allow to fill the tank with water and check the water height.

Usually by adjusting the floating ball height solve the issue. After that, the tank has to maintain a high water level.

Still, the issue exists- check the refill valve.

Defect Refill Valve is The Cause for Low Water in The Toilet Tank

The refill valve is responsible for filling the tank with water after each flush. The refill tube is the present left side of the tank and connects to the water supply line.

Whenever the toilet flushes down, the refill valve starts to fill the tank with water. The refill tube also has a significant height- that maintains the filling speed and the level.

Low height refill valve causing low water into the tank. Or broken Refill valve can miss out on the water to fill.

In the new toilet, one floating cup displays the top of the fill valve; instead of a floating ball. 

After a long time of using the toilet regularly, the fill tube can displace and need to adjust one more time. That’s why sudden low water in the tank.

To fix this issue, follow the steps

  • Remove the tank lid
  • Find the switch present back of the fill tube and turn it on to adjust the height
  • The float cup has another screw, turn clockwise, you get a ticking sound 
  • Flush the toilet and check the desired height you want. If it little low again, turn clockwise
  • In this way, you can resolve the issue

If all is ok, still get the disappointing result- Check the Water supply line.

Some time water supply link has a clog, and water can’t flow from there to the tank. 

  • Shut off the main water supply valve
  • then unscrew the bolt link to the tank
  • clean and check any debris present or not
  • Again, place and screw it

The water in My Toilet tank is Low Due to the Overflow Tube

The overflow tube is in the present middle of the tank, above the flush valve. Overflow tubes are usually wider, and larger than other tubes.

It is responsible to prevents overflowing from the tank after filling the tank. The excess water runs through the bowl.

Sometimes overflow tubes shatter by the water pressure. Consequently, it can not hold the water and passes through the rim. 

Due to flowing the water endlessly to the bowl, at the point- the tank water level is become very low and can not fill as much as it requires.

By replacing the overflow tube can resolve the problem. 

  • To replace an overflow tube, at first buy universal overflow tube, measure according to toiler toilet
  • Gently pull out the flush valve, then the overflow tube
  • Replace with the old one

Make sure the overflow tube top is always height about just below half an inch of the flush lever or fill tube and 3 inches of the top of the tank.

After knowing the reasons- “why is the water in the toilet tank low,” you need to settle the issue, Right? I have a detailed guide on how to increase water level into the toilet tank 10 steps afar.

Final Thought- Low Water into The Toilet Tank

Our toilet is one thing that uses each and every day. After heavy use, sometimes it shows some indication that helps to find out the upcoming issue that arises.

Like- If your toilet makes noise, what’s that mean

Symptoms of a blocked vent pipe

What if a sudden sewer smell coming from the bathroom

Leave a Comment