On most tub and shower combinations, the diverter is the small knob on the tub spout that you pull up to send water to the shower. Inside the spout it is a plastic gate that closes the spout opening. When the gate wears, water keeps coming out of the spout while the shower runs and the shower is weaker than it used to be. The usual fix is a new spout. The spout costs $20 to $80 and the replacement takes about 20 minutes.
Before you start. No need to shut off the water for this one; the valve stays closed while you work on the head, arm, or spout. You will need a towel to protect the finish, slip-joint pliers or an adjustable wrench, and a roll of plumber’s tape (thin white thread tape, about $2). If anything is corroded and will not loosen with moderate force, stop and see when to call a plumber. New to this? Start here explains the parts and tools in plain language.
Confirm it is the diverter
- Water runs from both the spout and the shower head at the same time: worn diverter gate.
- Pulling the knob does nothing, water stays at the spout: the gate has broken or come off its rod.
- Shower is weak and the spout dribbles, but was fine before: worn gate. If the shower was always weak, see low pressure first.
- A small trickle from the spout while the shower runs on a brand new spout is normal on many designs.
Why the spout is replaced rather than repaired
Globe Union, which makes Gerber and Danze spouts, and Danco both say the spout assembly is replaced when the diverter fails. Moen sells a replacement diverter gate kit for some of its spouts, which is worth checking if you have a Moen spout and want to keep the finish, but for most spouts the gate is not sold separately. Globe Union also notes that a copper pipe sticking out of the wall farther than the spout allows can block the gate, which is worth checking when a new spout fails the same way.
Replacing the spout
The steps and the way to tell a slip-on spout from a threaded one are on how to identify and replace a tub spout. Part numbers for each brand are on tub spout part numbers by brand.
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