The 400A is a standard refill valve that controls the water in the tank, it controls fill time and water level. The 400H is a performance fill valve that also controls the water in the tank. The 400H fill valve has an additional adjustment for the water in the toilet bowl using an independent adjustment knob. The 400H can be adjusted to let more or less water into the toilet bowl without affecting the level of water in the tank.

Fluidmaster make three fill valves that can be used to replace 400 valves that originally came in your toilet. Choose from the 400A, 400H and 400LSR fill valves.

Fluidmaster suggests using the 400A when replacing antiquated technology such as ballcocks and or when replacing “like” valves. Toilets manufactured after 2005, or are marketed as “Dual Flush, High Performance, or HET (High Efficiency Toilet)” we advise using the PerforMAX® 400H High Performance Fill Valve.

The Fluidmaster fill valve when activated fills both the tank and the bowl with water. The term higher refill rates describes the amount of water that is diverted to the toilet bowl. Our standard fill valve, the 400A, has a refill rate to the bowl that is standard for most toilets. A valve with higher refill rates can double the amount of water to the bowl and should be used on toilets that use less than 1.6 gpf or are stated to be higher performing toilets or High Efficiency Toilets.

H.E.T. is an acronym that spells out High Efficiency Toilet. What this term means is that the water consumption or usage of this toilet is less than the current government standard. The current standard for water usage in a toilet is 1.6 gallons per flush (GPF). Toilets that use less than 1.6 gpf are higher performing toilets or High Efficiency Toilets.

The 400AH does not come with a bowl refill dial instead it only comes with a (Roller) clamp that restricts water to the bowl. The 400AH is taller than the 400H version by 1 inch and comes with a regulator which tops the speed of refill by 2 gallons per minute. The 400H version is our newest mode and is more adjustable in that it has a separate bowl refill dial that allows easier adjustment to increase or decrease the amount of water going to the bowl, without changing the amount of water in the tank. The valve does not have a regulator but a restrictor which allows a faster flow than the AH version and can be as fast as 4 gallons per minute and  higher.