Toilet Advice

The Different Types of Toilet Flush Valves

2 inch flush valve

Every industry has what's known as a standard. These are the most common sizes and shapes for specific fixtures and hardware. Products measuring 2 inches are seen as the standard for toilets. Most bathrooms will be using this size. They are typically found in older, more traditional style tanks as well as lower flowing units. There is no shortage of options in this size and they are fairly easy to replace.

3 inch flush valve

Those measuring 3 inches have a water flow advantage over their 2 inch counterparts. The gap is larger, allowing larger volumes of water through at once, helping it achieve a more power. They are still found in many water efficient products. Toto, Kohler, and Mansfield all have product lines with 3" valves included. Simimlarly to 2 inch units, they are simple to replace in the event that something goes wrong.

Tower flush valve

As you know the flapper acts as a type of plug stoping water from exiting the tank until you activate a trip lever or button. While standard flappers only slightly open when activated, a tower valve opens it up in full, allowing water to rush through the opening from all angles. This increased rush of water can improve a toilets ability to remove waste from the bowl.

Dual flush valve

Dual flushing toilets are known for their ability to use two separate volumes of water. Most plumbing professionals refer to them as partial and full flushes. This is achieved through the use of a dual valve. These are often operated via two buttons on the tanks lid, but trip lever alternatives can also be found.

4 inch flush valve

If you've shopped around, you'll have noticed that 4 inch products are nowhere near as common as the others. This style produces the most power out of all of them and is operated via a piston that moves upwards. American Standard and their Champion 4 range are known for having this size.

Something we noticed in our research is that the bigger they get the higher they score they achieve on average through the MaP ratings scale. This is a testing system which analyzes individual models performance, and their ability to push waste through the bowl in one go with no blockages.

Want to learn more?

Check out our other toilet guides on our knowledgebase. You'll find guides showing you how to measure your rough in, and how much water you can save by upgrading to a watersense labelled toilet.