9 Plumbing Warning Signs

Learn about the Top Warnings Signs You Need to Repair or Replace the Plumbing Systems on your Rehab Project.


As a rehabber, you will need to be able inspect a property's plumbing systems to determine if the plumbing lines and equipment are outdated and need to be repaired or completely replaced to meet currently building codes and standards.

Sign #1: Old/Bad Water Supply Piping

Bad/Old Water Supply Piping

Bad Galvanized Water Supply Piping

Galvanized water supply lines are generally found on older homes built prior to 1960 and have issues with corroding from the inside causing low water pressure, discoloration of water & eventually leaks.
Galvanized Water Supply Piping

Bad CPVC Water Supply Piping

CPVC water supply piping is generally a good indication that a previous homeowner or unlicensed Contractor installed the plumbing, because CPVC is typically used for irrigation lines.

It has also been reported that CPVC piping & fittings can degrade over time causing leaks.
CPVC Water Supply Piping

Good/Modern Water Supply Piping

Copper & PEX water lines are current industry standard for water supply piping.

Copper is the most commonly used water supply piping found today, but PEX is becoming more commonly used because of the ease of installation and high cost of copper.

If you find Galvanized or CPVC water supply piping it may be a good idea to upgrade your supply lines to Copper or PEX Supply piping to meet current industry standars.
Copper PipingPex Water Piping

Sign #2: Old/Bad Waste Lines

Bad/Old Waste Line Piping

Bad Clay Pipe Waste Lines

​​Clay Piping waste are durable and can typically last 80 to 100 years, but similar to clay pipes, are susceptible to long-term ground settling, and pipe separation.  If you are buying a rehab property that was built in the 1930s to 1970s there's a good chance you may have issues with pipe breakage and sewage backups.
Broken Clay Piping

Acceptable Waste Line Piping

Black Cast Iron Waste Lines

Black Cast Iron waste lines are commonly found in older homes built before 1970.   Cast iron pipes are durable and can typically last 80 to 100 years, but similar to clay pipes, are susceptible to long-term ground settling, and pipe separation.  If you are buying a rehab property that was built in the 1930s to 1970s there's a good chance you may have issues with pipe breakage and sewage backups.
Cast Iron Waste Line Piping

Good/Modern Waste Line Piping


Today, ​PVC & CPVC is the industry standard for sanitary waste piping, so if you see PVC or CPVC in your property this is a good indication the plumbing was recently updated with new waste lines.
PVC Waste Piping
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Don't be overly alarmed if you have Clay or Black Cast Iron waste lines, but just know there's a good chance you may have to snake the piping or use high-pressure water-jetting to clear a clog for $250 to $750.

If you run into a separated/collapsed line, usually the plumber can make a 'spot repair' without replacing the entire line.

Sign #3: Old Hot Water Heaters

Hot water heaters generally only have a useful life of 8 to 12 years, so if you are buying an old fixer-upper there is a good chance the hot water heater needs to be replaced.
Leaky Hot Water Heater
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Check the Hot Water Heater's manufacturer's label to see if you can find the manufactured date.
Here's a guide on how to decipher the Model # & find the manufacturer's date for your hot water heater.

Sign #4: Copper Thieves

Copper piping in vacant homes is a prime target for copper thieves.  If your house has been ransacked by copper thieves you will be able to tell immediately because usually they will tear out drywall throughout the house to get access to the copper piping behind the wall.  

The easiest copper to access is the supply and distribution piping directly attached to the Hot Water Heater, so if that copper piping is missing, you've been ransacked.

Sign #5: Water Stains & Mold

Water stains, wood rot and mold are signs of water damage which can either be caused by rain water or your plumbing systems.

If the water stains and mold issues are located in, near or below a kitchen or bathroom there is a good chance you water supply lines or waste lines are leaking and will need to be fixed.

Locating leaks can be tricky and will likely require you to tear-out drywall and temporarily turn the water back on.
Ceiling Damage

Sign #6: Water Discoloration

Unless you’re under a boil order, have well water, or live in a rural area, discolored water is usually a cause for concern.

Brown or dark water is the result of corrosion in your pipes, leaving rust as the water runs through them.  If left untreated, mineral deposits can clog pipes, which under continual pressure can burst pipes.

Unfortunately, if you have discolored water you will likely need to replace all of the water supply piping in the home.

Sign #7: Gargling or Bubbling Sounds

Whenever you flush a toilet, run the dishwasher or laundry machine you may hear a gargling noise and potentially see water come out of the floor drains located in your basement, garage, laundry or utility room.  If you hear gargling there is a good chance there is a clog in your main waste line.

Sign #8: Clogged Drains

If you have sinks, tubs, and showers that drain slowly it could just be an isolated clog or it could be a sign of a much bigger issue with the main sewer line for your property.

Note:  If you run into a clog in a kitchen or bathroom sink, test other locations around the house to see if the issue is isolated to the individual drain or if it is a clog that is affecting the entire property.

Sign #9: Foul Odors

Smells of foul odors such as water, mold or sewage are another clear indicator that something is wrong with your plumbing system.  

Use your nose to sniff out the culprit and the location of the odor.

​The smell of stagnant water, dampness or mold could be an indication of a potential leak somewhere in the house.

The smell of sewage coming from a toilet could mean somebody just used the toilet 💩, or it may mean the wax ring is broken and leaking sewage in the bathroom.

If the odor is coming from the floor drains in your basement, garage or utility room that is a good indication there is a clog in your main waste line.
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