How long does it take to drain a walk-in tub? The same amount of time a regular tub takes to drain, except you need to wait until this happens before exiting. The standard tub drain and p trap is 1 1/2″. The p trap is plumbed into the main sewer drain. Gravity and a 1 1/2″ tub drain will only allow so much water through it regardless how many holes are drilled in the bottom of a tub. You could increase the diameter of the p trap and drain going to the larger sewer line, but unless the work is easily accessible, plumbing costs would be very high!
Some companies sell fast drains, 2″ drains, or dual drains with their walk in tubs in an effort to convince buyers their tubs have an advantage on speeding up draining time, but how effective are these features? Multiple drains in the bottom of a tub regardless of their diameter, or the use of a pump still requires the water to go through the standard single 1 1/2″ floor drain, and there is a limit to how much water can flow through it!
It takes some time for a persons body to cool off after bathing for 30 minutes in warm bath water, especially tubs equipped with In line heaters that keep temperature constant. So a bather busy rinsing off soap with warm water will be quite comfortable during the 2-3 minutes it takes for the bath water to drain. You’ll have to decide if the slight improvement you may or may not gain by adding a second drain or another electric pump is worth the extra expense. Having experienced both types, our installers have not seen any difference between them.