You can fix this
Likely cause: a worn diverter in the tub spout
If you pull up a knob on the spout to send water to the shower, the diverter is inside the spout. Delta says it cannot be repaired; the spout gets replaced.
Why this happens
Delta says a small, pencil-thin stream from the tub spout while the shower runs is normal. Excessive flow means the diverter inside the spout is worn, and Delta says that it cannot be repaired and the spout must be replaced. Replacement spouts are made for specific valves and pipe connections, so match yours.
How to fix it
- Look under the spout for a small set screw. A spout with a set screw slides off once it is loosened; one without usually unscrews.
- Remove the spout and note how it attached, then take it with you or photograph it to match the replacement.
- Buy a spout made for your valve brand and model. Delta specifies a genuine spout for its valves.
- Install the new spout, run the shower, and check for a pencil-thin stream or less.
When to stop. If the pipe behind the spout turns, cracks or leaks when you remove the spout, stop and call a plumber.
If this does not fix it, tell the plumber
- The tub spout runs heavily with the shower on, and it is a pull-up diverter spout.
- The valve brand, and whether the spout slides on or threads on.
- Whether you already replaced the spout.
Build the full list: what to tell the plumber.
Start this troubleshooter over
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