The 6 Plumbing Problems That Generate the Most Tenant Complaints
Your phone buzzes at 9:45 on a Tuesday night. The text says: No hot water. Again. The tenant in the second-floor unit has been dealing with lukewarm showers for a week, and now the hot water is gone entirely. This month you've already fielded two other calls — a slow tub drain in unit 1, a running toilet in unit 3 that nobody could sleep through.
Plumbing is the most common source of tenant complaints in rental properties. It's also where acting early keeps good tenants, and letting things slide doesn't.
Most complaints come back to the same handful of problems. Here's what causes each one, how to catch the signs before the call comes in, and what actually fixes it.
Quick-Reference: Most Common Rental Plumbing Complaints
| Complaint | Most Likely Cause | Fix Level |
|---|---|---|
| No hot water / runs out fast | Aged water heater, sediment buildup | Call a plumber |
| Slow or backed-up drain | Hair/grease buildup, root intrusion, pipe scale | Snake or hydro jet |
| Running toilet | Failed flaper, worn fill valve | DIY or plumber |
| Low water pressure | Scale in galvanized lines, partially closed valve, PRV | Plumber diagnosis |
| Leaking faucet | Worn washer, O-ring, cartridge | DIY or plumber |
| Sewer smell | Dry P-trap, failed wax ring, venting issue | Plumber |
| Banging pipes | Water hammer, loose pipe straps | Plumber |
No Hot Water — Or Water That Runs Out Before the Shower Ends
This one creates the most urgency of any complaint on the list. Cold showers aren't a minor inconvenience. They're the kind of problem that sends tenants to rental review sites and starts conversations about lease renewals.
The usual cause is a water heater past its useful life. A standard tank unit lasts 8–12 years. In Berks and Montgomery Counties, where the water carries high mineral content, the actual lifespan tends to run shorter. Dissolved calcium and magnesium settle on the floor of the tank as sediment every time the water heats up. That layer insulates the water from the burner — the unit works harder, heats less efficiently, and the first sign is hot water that runs out faster than it used to. The popping or rumbling during heating cycles is that sediment cooking against the tank floor.
If the water heater in your rental is more than 10 years old and the tenants have started complaining about inconsistent hot water, the unit is telling you where it's headed. Flushing the tank annually slows sediment buildup. It doesn't reverse it. Replacement, not repair, is almost always the right call at that age.
In multi-unit buildings, the more common complaint is hot water that simply isn't enough to go around during peak morning hours. That's a sizing problem — the unit was undersized for the actual occupancy. A high-recovery tank or a tankless system solves it.
Slow Drains and Drain Backups
Tenants report slow drains constantly. And there's a real difference between a drain that's slow and one that's about to back up into the unit — but you won't always know which one you're dealing with until it's too late.
In a single drain, the clog is usually close to the fixture: hair and soap scum in a tub drain, grease and food particles in a kitchen sink, wet wipes in a toilet drain. The packaging says "flushable." They're not. A cable snake clears most of these without much trouble.
When multiple drains in the same unit slow at the same time, the blockage is deeper in the shared line. That's a different repair — usually hydro jetting to clear the buildup, or a camera inspection if the line keeps coming back despite cleaning.
Here is something a lot of landlords don't think about: in older rental properties — and a lot of the housing stock in established neighborhoods in this part of PA was built before 1970 — the drain lines are often cast iron. Cast iron is durable, but the interior surface roughens as it corrodes over decades. That rough texture catches grease and debris the way a smooth PVC pipe never would. What looks like a tenant behavior problem (too much grease, wrong things flushed) is sometimes just an aging pipe that no longer clears itself. Running a camera through it tells you which one you're actually dealing with.
Root intrusion in the main sewer lateral is the worst version. Roots enter at clay-pipe joints, which are common in pre-1960 neighborhoods, push through hairline cracks, and fan out inside the pipe into a mesh that catches everything. A snake buys time. Hydro jetting buys a little more. Eventually, the line needs to be repaired or replaced.
Running Toilets
A toilet that runs constantly wastes roughly 200 gallons of water per day. If you are covering utilities, that shows up in the bill fast. If the tenant pays utilities, they'll tell you. Either way, it's a problem worth fixing the week it appears.
The fix is usually cheap. After a flush, the flapper — a rubber valve at the bottom of the tank — is supposed to seat back down and stop water from flowing into the bowl. When it warps, hardens, or builds up a mineral deposit along its sealing edge, it doesn't seat. Water trickles through, the fill valve keeps running to compensate, and the toilet never shuts off. A new flapper costs about $10 and takes 15 minutes.
But if a new flapper doesn't stop it, the fill valve itself may be worn. That's another $20 part and 20 more minutes with the shutoff valve under the tank. Water leaking from around the base of the toilet — not condensation, but actual water on the floor — usually means the wax ring has failed and the toilet needs to be reset.
A lot of the older toilets in pre-1980 rentals use ballcock-style fill valves that have simply run out of road. Replacing the entire flush mechanism at once — flapper and fill valve together — is often faster than troubleshooting a 40-year-old assembly one part at a time.
Low Water Pressure
Low pressure can come from several directions, and the cause isn't always obvious from the symptom alone.
The most common cause in older rentals is galvanized steel supply lines that have scaled from the inside. Galvanized pipe corrodes from the interior outward over decades — mineral deposits narrow the pipe's effective diameter the way scale builds up inside a teakettle that's never been descaled. A pipe originally 3/4 inch in diameter can restrict down to an effective opening of 1/4 inch or less. The water pressure at the fixture feels weak because it is. The water physically can't get through fast enough.
Low pressure at one fixture is a different problem. Start with the aerator — the small screen at the end of the faucet spout. Hard water clogs them constantly, and pulling and cleaning the aerator takes two minutes and fixes the problem about half the time. A partially closed shutoff valve under the sink is the other quick check.
Low pressure throughout an entire unit points to the supply lines, a worn pressure regulating valve (PRV), or a partially closed main valve. That's a plumber-with-a-gauge call — the diagnosis takes a few minutes but you need actual numbers to know what you're working with.
And in multi-unit buildings, low pressure in upper-floor units during peak morning hours is usually a flow-sharing problem. Everyone's using water at once, and the supply lines weren't designed for it.
Leaking Faucets
A faucet that drips once per second wastes about 3,000 gallons of water per year. In a rental, that's real money, and the sound is irritating enough that tenants will report it quickly — which is actually useful. A reported drip is easier to fix than a slow leak that goes unnoticed for months.
Most faucet leaks trace to a worn washer, O-ring, or cartridge. The fix depends on the faucet design. On a compression faucet — common in older homes — a worn washer at the stem is usually the problem. On a cartridge-style faucet, the cartridge itself wears out and needs replacing. Neither job is complicated, but they're different jobs.
In older rental properties, the faucets are sometimes original 1970s-era fixtures. Replacement parts for some of those models haven't been manufactured in decades, and hunting for a discontinued washer size is a frustrating way to spend an afternoon. A full fixture replacement is more practical in those cases.
A faucet leaking at the base — water pooling around where the fixture meets the sink — is a different problem from a dripping spout. That usually means a worn O-ring or a loose packing nut, and it needs to be fixed before the water works its way into the cabinet below.
Sewer Smell Coming From Drains
This is one of the more alarming things a tenant can report. And more often than not, the fix is simple.
Every drain in a plumbing system connects through a P-trap — the curved pipe section under the sink or tub that holds a small pool of water. That water is what blocks sewer gases from traveling up through the drain and into the unit. When a drain isn't used for several weeks — a basement utility sink, a guest bath tub, a floor drain — the water in the trap evaporates and the seal disappears. Running water down the drain for 30 seconds refills it and ends the smell. That's the whole fix.
Persistent odors that affect multiple drains or rooms point to a venting problem. A blocked or broken vent stack creates negative pressure in the drain lines, which siphons the P-traps dry faster than normal. That's a plumber's diagnosis.
A sewer smell near the base of a toilet — worse in warm weather — usually means the wax ring has failed. The toilet needs to come up and be reset.
Banging Pipes (Water Hammer)
A deep thud or bang inside the walls when a faucet shuts off or a washing machine valve closes quickly is water hammer. It happens when fast-closing valves — solenoid-operated appliance valves are the usual suspects — stop water mid-flow. The momentum has nowhere to go and slams against the closed valve.
Annoying at first. But repeated water hammer stresses pipe joints and can eventually cause leaks. An arrestor installed at the washing machine connections, or near the PRV, absorbs the pressure wave and ends it. Not an expensive fix.
Preventing Complaints Before They Start
The landlords with the lowest emergency plumbing bills are the ones walking through their units once a year before problems announce themselves with a late-night text.
Flush the water heater annually to slow sediment buildup. Check faucet aerators and toilet flappers — both are $5 parts that, when worn, generate two of the three most common tenant complaints. Run water down floor drains and infrequently used sinks to keep P-trap seals intact. And if the building has galvanized supply lines that are more than 30 years old, start budgeting for repiping. It's not a matter of whether those lines will need to be replaced.
The call at 9:45 on a Tuesday is expensive. The walkthrough in March is not.
Frequently Asked Questions
Urgency determines the timeline. No hot water or sewage backup affecting a tenant's ability to use the unit is an emergency requiring a same-day or next-day response. A dripping faucet isn't an emergency, but it should be addressed within a few days. The specific timing in your lease agreement and local housing codes govern the formal obligation, but waiting weeks on any active plumbing complaint creates bigger problems — for the property and the tenant.
Damage from misuse is generally on the tenant: flushing wipes or foreign objects that clog a drain, breaking a fixture through rough handling, or failing to report a slow leak until it becomes a flood. Normal wear and tear — a flapper that fails after years of use, a water heater that reaches the end of its lifespan, a P-trap seal that dries out — falls on the landlord.
Check pressure in more than one fixture. If pressure is low throughout the unit but normal in an adjacent unit, the issue is inside your building — a partially closed valve, a worn PRV, or scaled galvanized supply lines. If pressure is equally low across multiple units, that points to a supply-side issue worth a call to the water company.
If the repair resulted from documented misuse — a clog caused by items that shouldn't have been flushed — you may be able to charge the tenant, especially if your lease addresses tenant-caused damage. Normal wear-and-tear repairs are the landlord's cost. Having documentation matters: photos, a written report from the plumber, and a record of the complaint history will carry weight if the issue becomes a dispute.
Once a year is practical for most single-family rentals. Multi-unit buildings benefit from semi-annual checks. Cover the water heater condition and age, visible supply and drain lines for corrosion or signs of slow leaks, toilet flush mechanics, faucet aerators, water pressure at a few fixtures, and any floor drains that may have dry P-traps.
Replacing the toilet internals — flapper and fill valve together — and cleaning faucet aerators across all units costs very little and takes out two of the top three complaint categories in one afternoon. Replacing an aging water heater proactively, before it fails, avoids emergency rates and tenant displacement. Those two actions prevent most of the calls.
A tenant who doesn't complain about plumbing isn't a low-maintenance tenant. They're a tenant whose plumbing works. The difference almost always comes down to whether the system gets looked at once a year or only when something breaks.
