Dual flush toilet wasted more water, how to fix it

Key Takeaways

• Recently I discovered I have in fact actually wasted water for nearly three years
• I learned that I need to re-adjust the Dual Flush by Danco
• The URL for my original installation video is: If you are like me and did not verify that in fact we are using less water, now I can show you my method so that you can double check your dual flush system and re-adjust it if necessary to save water
• Index This video only applies to the Dual Flush made by Danco since the Fluidmaster Duoflush has a different design, and does not have the same problem

Understanding the Basics

The most common reason a dual-flush system wastes water is that the partial flush valve is not closing completely or is closing too slowly. This means water continues to trickle into the bowl long after the flush cycle should have ended. Another cause is that users press the wrong button (full flush when partial would suffice) because the buttons are not clearly labeled or are confusing. A third issue is that the partial flush is set too low to actually clear the bowl, causing people to flush twice — using more water than a single standard flush would have used.

The DIY Advantage

A toilet that runs continuously even at a trickle can waste 200 gallons per day — over 6,000 gallons per month. Even a small flush valve leak adds significant cost to your water bill.

Tips for Best Results

Check for a slow leak by adding food coloring to the tank water and waiting 30 minutes without flushing. If the colored water appears in the bowl, the flush valve is leaking. Adjust the partial flush duration so it is just enough to clear the bowl for liquid waste. Make sure the valve seal is clean and free of mineral deposits. Label the buttons clearly (most kits include stickers) so everyone in the household knows which button is which.

Video Chapter Guide

Here is a quick reference for the key sections covered in the video:

• 0:00 Dual flush toilet may waste more water
• 0:34 my Dual flush Danco wasted water for 3 years
• 1:29 Dual flush Danco Installation Instruction not good
• 2:06 measure full flush water
• 3:04 full flush = 2.5 gallons
• 3:44 two ways to adjust the height of the refill valve float
• 4:28 quick flush blue float
• 5:36 two parts: yogurt container+gallon milk jug
• 6:48 quick flush=0.9G ; full flush=1.2G
• 7:08 tri-flush system

Use these timestamps to jump directly to the section most relevant to your situation.

More Practical Guides

Fixing a malfunctioning dual-flush system restores the water savings that motivated the conversion in the first place.

For more hands-on tutorials, check out our guides on bathtub caulking and peeling garlic easily without special tools. Each one follows the same practical, no-nonsense approach to help you save money and build useful skills.