What is a washdown toilet?
North American toilets most commonly utilize siphon jet technology. Most of the water in the tank is used to create a vacuum or siphon effect in the trapway of the toilet bowl, which then pulls the waste out after the water. In the past, several North American toilets have been subject to clogging due to the lower volumes of water used in ultra low flow toilets. The trapways of the bowls had to be reduced to allow the vacuum to be created.
