Is It Safe to Turn On a Shower You Haven’t Used in Years?

"Is It Safe to Turn This On?" – A Call That Got Us Thinking

We recently got a call from a homeowner – let’s call her Linda – who sounded a little nervous. She told us she has a three-bedroom house with a shower and a tub she hasn’t used in about three years. She’d had us out before to clear a clogged shower drain, and everything went great, so this time she wanted to know if we could inspect those long-unused fixtures while she turned them on.

As we talked through it with her, we reassured her that she wasn’t being overly cautious. We see this situation a lot as a plumbing company – unused guest bathrooms, in-law suites, or rental units that sit empty for months or years. And from our experience, plumbing really doesn’t like being ignored.

In this post, we’ll walk you through what we explained to Linda: what can happen when a shower or tub sits unused for years, what we recommend you check yourself before turning things on, and when it’s smart to call us (or another licensed plumber) for a professional inspection.

What Happens to Showers and Tubs That Sit for Years?

When you don’t use a bathroom for a long time, a few things can happen behind the scenes. We’ve seen all of the following in homes just like Linda’s:

• Dry drain traps: Every shower and tub has a P-trap that’s supposed to stay filled with water to block sewer gases. When it sits too long, that water can evaporate. We often see this result in strong sewer or “rotten egg” odors the first time someone opens the door or runs water again.
• Corrosion and mineral buildup: If you have hard water, minerals can build up in shower valves, cartridges, and showerheads. When fixtures sit, those deposits can harden. We sometimes find handles that are stiff or stuck and showerheads that spray sideways or barely at all.
• Hidden leaks in old lines: If a pipe or fitting was already weak, years of temperature changes and inactivity can make it worse. We’ve opened access doors like the one Linda mentioned behind walls or ceilings and found slow, hidden leaks that only show up once the water is turned back on.
• Sediment and rusty water: If your home has galvanized pipes or an older water heater, long-unused lines can deliver discolored or rusty water at first. We often see that on the first run after a long break.
• Mold and mildew issues: If there was a past leak that wasn’t fully resolved, that unused bathroom can quietly become a mold nursery. We’ve used small inspection cameras and moisture meters to confirm what’s going on behind tile and drywall.

Signs of Potential Problems Before You Turn Anything On

When we visit a home like Linda’s, we don’t just walk in and flip the handle. We take a few minutes to look and sniff around first, and we recommend you do the same. Here are things we suggest you check before running water:

• Odors when you open the door: If you smell sewer gas or a strong musty odor as soon as you walk into the bathroom, that tells us a trap may be dry or there could be a venting or leak issue.
• Stains on ceilings or walls below: If this is an upstairs shower or tub, walk to the room below it and look up. We always check for yellow or brown stains, peeling paint, or bubbling drywall – classic signs a line or drain may have leaked in the past.
• Condition of caulking and grout: We look closely at the joints around the tub, shower corners, and along the floor. Cracked or missing caulk and crumbling grout are invitations for water to get behind the surfaces.
• Access panels or doors: Like Linda, many homeowners have small access doors installed where there were previous repairs. We recommend opening those panels and looking for any dampness, discoloration, or musty smell before using the shower or tub again.

Simple Checks We Recommend Before Turning On a Long-Unused Fixture

There are a few basic checks we’re comfortable recommending homeowners do themselves before fully putting an old shower or tub back into service. When we arrive for a call like this, we often follow a similar first-step routine:

• Turn the water on slowly: We always start by gently cracking the valve open instead of swinging it to full blast. You can do this too. Listen for any banging, whistling, or unusual vibration in the pipes.
• Watch the showerhead and tub spout: At first run, we look for rusty, cloudy, or very dark water and note how long it takes to clear. If it doesn’t clear in a minute or two, that’s something we’ll want to investigate.
• Check under and behind: While the water is running, we go to any access panel or to the ceiling below (if it’s a second-floor bath) and look for active dripping or new moisture. We recommend you do the same, especially in areas that had previous leaks.
• Run the drain and watch the floor: After a minute or two, we close the drain (for a tub) or let water pool slightly in the shower pan, then let it drain while watching for slow draining, gurgling, or water appearing where it shouldn’t.
• Re-fill dry traps: If we suspect the trap is dry (because of odor), we pour a couple of cups of water down the drain and see if the smell improves. You can do that safely on your own.

When We Recommend Calling a Plumber First

Linda’s instinct to have us on-site before really using those fixtures again was a good one, especially since she’d had previous leaks and drywall repairs in that area. We often suggest bringing in a professional before you start regular use again if:

• There’s a history of leaks in that bathroom or in the ceiling below it.
• You see any active moisture, staining, or mold around the tub or shower, or inside an access panel.
• The fixtures are 20+ years old and have never been updated.
• You notice very low or very high water pressure when you first test them.
• You smell persistent sewer gas even after refilling the trap with water.

During a professional inspection, we may use moisture meters, small cameras, and other diagnostic tools to make sure there isn’t a hidden issue waiting behind the walls. Like we told Linda on the phone, we always review our findings and pricing with you before starting any repairs, so you’re not surprised.

Thinking About Turning On a Long-Unused Shower or Tub?

If you’re staring at a guest shower or old tub you haven’t used in years and wondering, “Is it safe to just turn this on?” you’re not alone. We help homeowners through this exact situation all the time.

Our advice: do a careful visual check first, turn things on slowly, and if you see or smell anything that doesn’t feel right – or if there’s a history of leaks – let us take a look. A quick inspection now can save you from a much bigger mess later.

And if you’re like Linda and have been putting this off because you’re nervous, we get it. That’s exactly what we’re here for.