A high efficiency furnace’s main burner shuts off after initial ignition
A toilet is cycling on and off, and the tank is refilling every few minutes. What should you check first?
1) flush valve
2) fill valve
3) flapper
4) handle
5) overflow tube
The correct answer and explanation is :
The correct answer is:
3) Flapper
Explanation:
When a toilet tank refills every few minutes without being flushed, it indicates a leak. The most common cause of this issue is a faulty flapper—a rubber seal at the bottom of the tank that controls water flow into the bowl.
How the Flapper Causes the Problem
- Worn-Out or Misaligned Flapper: Over time, the flapper can degrade, harden, or crack, preventing it from sealing properly. This allows water to slowly leak from the tank into the bowl.
- Chain Issues: If the flapper chain is too short, it can prevent the flapper from closing completely. If it’s too long, it may get caught under the flapper, also causing a leak.
- Debris or Buildup: Mineral deposits or debris on the flapper or the flush valve seat can prevent a tight seal, leading to continuous leakage.
How to Check the Flapper
- Visual Inspection: Open the toilet tank and inspect the flapper for wear or improper seating.
- Dye Test: Add a few drops of food coloring to the tank. If the color appears in the bowl without flushing, the flapper is leaking.
- Manual Adjustment: Press down on the flapper; if the leak stops, the flapper likely needs to be replaced.
Solution
If the flapper is damaged, replace it with a compatible one. If the flapper is in good condition but not sealing properly, clean the valve seat or adjust the chain length.
Why Not Other Options?
- Flush Valve: A faulty flush valve can cause leaks but is less common than a bad flapper.
- Fill Valve: A defective fill valve usually causes continuous running, not intermittent cycling.
- Handle: A stuck handle can keep the flapper open, but you would likely notice it staying down.
- Overflow Tube: Water going into the overflow tube indicates a high water level, usually due to a fill valve issue.
Thus, checking the flapper first is the best approach.