Bathtub Faucet Won’t Switch to Shower: Causes and Fixes

How the Diverter Works

The diverter is a small valve that redirects water. Depending on your plumbing setup, it may be:

• Tub Spout Diverter: A pull-up knob or lever on the tub spout.
• Two-Handle Diverter: A separate handle between hot and cold knobs.
• Single-Handle Diverter: Built into the faucet cartridge or valve.

When the diverter is working properly, it closes off the tub spout so water flows only to the showerhead. If it’s worn or clogged, it won’t seal fully, and water keeps flowing from the tub faucet.

Common Reasons Your Tub Faucet Won’t Switch to Shower

• Worn Diverter Valve: Over time, internal parts wear out and stop sealing.
• Mineral Buildup: Hard water deposits can block the diverter from moving fully.
• Corroded or Damaged Tub Spout: A cracked or rusted spout won’t allow proper redirection.
• Faulty Cartridge (Single-Handle Faucets): If the diverter is built into the cartridge, a replacement may be needed.
• Improper Installation: If the spout wasn’t fitted correctly, the diverter won’t function properly.

How to Fix a Bathtub Faucet That Won’t Switch to Shower

Step 1: Clean the Diverter

Mineral deposits are a common culprit. If you have a tub spout diverter, pull it off and soak it in vinegar for an hour. Scrub away buildup before reinstalling.

Step 2: Replace the Tub Spout

If your tub spout has a built-in diverter and cleaning doesn’t work, replacing the spout is usually the easiest fix. Make sure to buy the correct type—slip-on or threaded—to match your plumbing.

Step 3: Replace the Diverter Valve

If you have a two-handle system, the diverter is a separate valve. You’ll need to shut off the water, remove the handle, and replace the valve stem inside.

Step 4: Replace the Faucet Cartridge

In single-handle systems, the diverter is built into the cartridge. If it fails, replacing the cartridge restores shower functionality.

Step 5: Call a Plumber (if needed)

If your diverter is inside the wall or part of an older system, a plumber may need to cut into the wall to access and replace it.

Tools You’ll Need

• Adjustable wrench
• Allen wrench (for set screws)
• Replacement tub spout, diverter valve, or cartridge
• Plumber’s tape
• Vinegar and scrub brush (for cleaning buildup)
• Silicone grease (to lubricate new parts)

Estimated Repair Costs

• Tub spout with diverter: ₦8,000–₦25,000 ($20–$50 internationally).
• Diverter valve replacement: ₦15,000–₦40,000 ($40–$100 internationally).
• Cartridge replacement: ₦20,000–₦60,000 ($60–$150 internationally).
• Professional plumber service: ₦15,000–₦40,000 ($100–$200 in the US).

How to Prevent Diverter Problems

• Clean the tub spout and shower parts regularly to prevent mineral buildup.
• Operate the diverter gently—avoid forcing the lever or knob.
• Install a water softener if you have hard water, which causes scale buildup.
• Replace worn parts promptly before they cause larger leaks.

FAQs

1. Why won’t my tub spout diverter stay up?

The internal spring or rubber washer is worn out. Replacing the spout is usually the best fix.

2. Can I just repair the diverter instead of replacing it?

Sometimes, cleaning and replacing washers helps, but in most cases, replacement is more reliable and cost-effective.

3. Should I replace the entire faucet system if the diverter fails?

Not necessarily. If the faucet is otherwise in good condition, replacing just the diverter or spout is enough.

4. Is it normal for some water to come from the tub faucet when the shower is on?

A slight trickle is normal, but a steady stream means the diverter is failing.

5. How long should a tub diverter last?

Most diverters last 5–10 years depending on water quality and usage.

Conclusion

If your bathtub faucet won’t switch to the shower, the diverter is the likely culprit. Start with cleaning to remove mineral buildup, then move on to replacing the spout, valve, or cartridge if necessary. With the right tools, most homeowners can handle this repair themselves. For more complex setups, a plumber can quickly fix the issue. Addressing it promptly will restore full shower function, save water, and extend the life of your plumbing system.