Course outline
Module 1
Module 1: Understanding Your Home's Water Supply
Understanding Your Home's Water Supply
Knowledge check
Q1. Which part of a home's plumbing system is responsible for bringing water in from the municipal main or well?
- A. Drain line
- B. Water service line ✓
- C. Vent stack
- D. P-trap
Why: The water service line is the pipe that connects your home to the municipal water main or well, delivering water into the house before it is distributed to fixtures and appliances.
Q2. What is the main purpose of a main shutoff valve in a home?
- A. To regulate water pressure throughout the day
- B. To stop all water flow into the house in an emergency or during repairs ✓
- C. To heat water before it reaches the faucets
- D. To filter sediment out of the supply line
Why: The main shutoff valve lets you cut off water to the entire home, which is essential during leaks, burst pipes, or when making plumbing repairs.
Q3. What does a pressure regulator (pressure reducing valve) do in a home water system?
- A. It increases water flow to the upper floors
- B. It removes hardness minerals from the water
- C. It lowers incoming water pressure to a safe level for household pipes and fixtures ✓
- D. It measures how much water the household uses
Why: Municipal water pressure can be higher than household plumbing is designed to handle. A pressure regulator reduces it, typically to around 40 to 80 psi, to prevent pipe damage, leaks, and appliance failure.
Q4. Which type of pipe material is commonly used for household supply lines and is flexible, resistant to freezing damage, and easy to install?
- A. Cast iron
- B. Clay tile
- C. PEX (cross-linked polyethylene) ✓
- D. Concrete
Why: PEX is a flexible plastic piping material widely used for water supply lines. It resists scale buildup, tolerates some freezing without bursting, and requires fewer fittings than rigid pipes.
Q5. Why is it useful for a homeowner to know where the water meter is located?
- A. It shows how many fixtures are in the house
- B. It allows you to check for hidden leaks by monitoring whether the meter moves when all water is off ✓
- C. It controls the temperature of hot water
- D. It filters out contaminants before they reach the kitchen sink
Why: If the meter's dial or leak indicator keeps moving while no water is being used, it suggests a hidden leak somewhere in the system, helping you catch problems early.
Module 2
Module 2: Identifying Pipes and Fittings
Identifying Pipes and Fittings
Knowledge check
Q1. Which type of pipe is commonly identified by its white or off-white color and is often used for drain, waste, and vent (DWV) lines in homes?
- A. Copper
- B. PVC (polyvinyl chloride) ✓
- C. Galvanized steel
- D. PEX (cross-linked polyethylene)
Why: PVC is typically white or off-white and is widely used for drain, waste, and vent lines because it is lightweight, corrosion-resistant, and easy to join with solvent cement. Copper is reddish-brown, galvanized steel is gray with a zinc coating, and PEX is usually colored red, blue, or white but is flexible tubing rather than rigid pipe.
Q2. What does a copper pipe that has a reddish-orange or brownish-pink color indicate about the material?
- A. It is galvanized steel coated with zinc
- B. It is plastic tubing that has been dyed
- C. It is copper, which is a common material for household water supply lines ✓
- D. It is cast iron that has rusted on the surface
Why: Copper has a distinctive reddish-orange to brownish-pink color when new and tends to darken over time. It is widely used for household water supply lines because it resists corrosion and handles heat well. Galvanized steel looks gray or silver, and cast iron is dark gray or black.
Q3. Which fitting is used to connect two pipes of the same diameter in a straight line?
- A. Elbow
- B. Tee
- C. Coupling ✓
- D. Cap
Why: A coupling joins two pipes end to end in a straight line, usually with the same diameter. An elbow changes direction, usually by 90 or 45 degrees. A tee creates a branch connection, and a cap closes off the end of a pipe.
Q4. A homeowner finds a pipe with a fitting that has a threaded end. What is the most likely purpose of threaded fittings in home plumbing?
- A. They are used only for gas lines and never for water
- B. They allow connections to be made and disassembled without soldering or solvent cement ✓
- C. They are decorative and do not affect water flow
- D. They are used exclusively for drain lines below the floor
Why: Threaded fittings let plumbers and homeowners connect or disconnect pipes without heat or chemical bonding, which makes them useful for fixtures, valves, and places that may need future service. Threaded connections are used for water and gas lines and are not purely decorative.
Q5. Which pipe material is flexible, often comes in coils, and is commonly used for modern water supply lines because it resists freezing damage better than rigid pipes?
- A. Cast iron
- B. PEX (cross-linked polyethylene) ✓
- C. Black iron
- D. ABS (acrylonitrile butadiene styrene)
Why: PEX is a flexible plastic tubing that comes in coils and is popular for water supply lines. Its flexibility allows it to expand slightly if water freezes, reducing the risk of bursting compared with rigid pipe. Cast iron and black iron are rigid metal pipes, and ABS is a rigid black plastic used mainly for drain lines.
Module 3
Module 3: Tools Every Homeowner Needs
Tools Every Homeowner Needs
Knowledge check
Q1. Which tool is best suited for gripping and turning pipes and fittings with a rounded or irregular shape?
- A. Hacksaw
- B. Pipe wrench ✓
- C. Allen key
- D. Utility knife
Why: A pipe wrench has serrated jaws that bite into rounded pipe surfaces, giving the grip needed to turn threaded pipes and fittings. Other tools listed are designed for cutting or for hex-socket screws, not for gripping round pipe.
Q2. What is the main purpose of a plunger in a basic household plumbing toolkit?
- A. To measure water pressure
- B. To cut through copper pipe
- C. To clear clogs in toilets and sinks by creating suction and pressure ✓
- D. To seal threaded joints
Why: A plunger uses alternating pressure and suction to dislodge blockages in drains and toilets. It is one of the most common first-response tools for clogs, and it works best when the cup forms a tight seal over the drain opening.
Q3. Which tool is used to cut plastic (PVC) pipe cleanly and squarely?
- A. Tube cutter
- B. Pipe cutter for PVC or a fine-tooth saw ✓
- C. Channel-type pliers
- D. Torch
Why: A dedicated PVC cutter or a fine-tooth hacksaw makes a clean, square cut needed for solvent-welded joints. A torch is used for soldering copper, not for cutting plastic pipe.
Q4. Why should a homeowner keep Teflon (PTFE) tape on hand?
- A. To insulate electrical wires
- B. To glue pipes permanently together
- C. To help create a watertight seal on threaded pipe connections ✓
- D. To protect wood from rot
Why: PTFE thread seal tape fills the small gaps between male and female threads, helping prevent leaks at threaded joints. It should be wrapped in the direction of the threads so it does not unravel when the fitting is tightened.
Q5. What is the primary use of an adjustable basin wrench?
- A. Tightening nuts in tight spaces under a sink, such as the faucet mounting nut ✓
- B. Cutting drywall
- C. Measuring the flow rate of a faucet
- D. Driving screws into studs
Why: A basin wrench has a long shaft and a pivoting jaw that reaches up behind a sink or faucet to loosen or tighten mounting nuts that are inaccessible with a regular wrench. It is a specialized tool that makes under-sink work far easier.
Module 4
Module 4: Fixing Leaky Faucets and Valves
Fixing Leaky Faucets and Valves
Knowledge check
Q1. What is the most common cause of a dripping compression faucet?
- A. A cracked faucet spout
- B. A worn rubber washer at the base of the valve stem ✓
- C. Too much water pressure in the main line
- D. A clogged aerator screen
Why: In compression faucets, the rubber washer at the bottom of the valve stem compresses against the valve seat to stop water flow. Over time it wears out or hardens, allowing water to seep through and drip from the spout.
Q2. Before disassembling a leaking faucet, what should you do first?
- A. Turn off the hot water heater
- B. Close the shutoff valves under the sink or the main water supply ✓
- C. Remove the handle with a hammer
- D. Apply penetrating oil to the faucet body
Why: Shutting off the water supply prevents flooding and water damage during repair. Opening the faucet after shutting off the supply also helps drain residual water from the lines.
Q3. Which tool is typically needed to remove a faucet handle screw on many single-handle faucets?
- A. A pipe wrench
- B. A hacksaw
- C. A Phillips or Allen (hex) screwdriver, depending on the model ✓
- D. A tubing cutter
Why: Many faucet handles are secured by a set screw or cap screw that requires a Phillips or hex (Allen) key. The exact type depends on the faucet manufacturer, so checking the model is important.
Q4. What should you do with the old washer or O-ring when replacing it?
- A. Reuse it if it looks mostly intact
- B. Match it exactly to the original size and type before installing the replacement ✓
- C. Coat it in sealant and reinstall it
- D. Replace it with a metal gasket of any size
Why: Washers and O-rings must match the original dimensions and material to seal properly. Bring the old part to the hardware store to find an exact match, since a wrong size will continue to leak.
Q5. After repairing a faucet and turning the water back on, what is the recommended check?
- A. Wait one week to see if the leak returns
- B. Run the faucet and inspect all connections and the spout for drips or seepage ✓
- C. Pour boiling water through the faucet
- D. Tighten every fitting as hard as possible
Why: Turn the water on slowly, run the faucet, and check the spout, handle base, and supply connections for leaks. Overtightening can damage parts, so a careful visual inspection is the proper test.
Module 5
Module 5: Clearing Clogged Drains Safely
Clearing Clogged Drains Safely
Knowledge check
Q1. Which of the following is the safest first step when a bathroom sink drain is slow to empty?
- A. Pour a bottle of concentrated chemical drain cleaner down the drain immediately
- B. Remove the stopper and clean out visible hair and debris by hand or with a small hook ✓
- C. Add boiling water mixed with bleach to the drain while the sink is full
- D. Disconnect the drain pipe under the sink while water is still standing in it
Why: Removing visible hair and debris is a simple, low-risk first step that clears many slow drains without chemicals or tools that could cause injury or damage.
Q2. Why should you avoid mixing different chemical drain cleaners together?
- A. They will cancel each other out and leave the clog unchanged
- B. They can react violently and release toxic or dangerous gases ✓
- C. They will make the pipes too slippery for water to flow through
- D. They only work when used in a specific order, so mixing wastes product
Why: Many drain chemicals, such as those containing bleach, acids, or lye, can react dangerously when combined, producing heat, splattering, or toxic fumes.
Q3. What is a plunger most effective at clearing?
- A. Grease that has hardened along the pipe walls
- B. Tree roots growing into the sewer line
- C. A blockage close to the drain opening caused by air pressure and water movement ✓
- D. Mineral buildup inside the water heater
Why: A plunger works by creating pressure and suction to dislodge clogs near the opening, such as in sinks, tubs, and toilets, though it is less effective on deep or heavy blockages.
Q4. When using a drain snake (auger) on a sink drain, what should you do?
- A. Push it in as hard and fast as possible to break the clog apart
- B. Turn the handle slowly and gently while feeding it in, then withdraw it carefully ✓
- C. Leave it in the drain overnight so it can work on the clog
- D. Use it only after pouring hot chemical cleaner into the drain
Why: Feeding the snake slowly while turning it helps it hook or break up the clog without scratching or damaging pipes, and slow withdrawal pulls debris out with it.
Q5. If a drain remains clogged after you have tried basic methods, and multiple fixtures in the home are draining slowly, what is the most appropriate action?
- A. Keep applying stronger chemicals until the clog clears
- B. Pry open the main cleanout with a wrench while the water is running
- C. Contact a licensed plumber, since the blockage may be in the main sewer line ✓
- D. Remove the toilet and pour water directly into the main drain
Why: Slow drains throughout the house point to a main line blockage, which may require professional equipment and can be hazardous or costly to fix incorrectly.
Module 6
Module 6: Toilet Repair and Maintenance
Toilet Repair and Maintenance
Knowledge check
Q1. What is the most common cause of a toilet that keeps running after flushing?
- A. A cracked toilet bowl
- B. A worn or misaligned flapper valve ✓
- C. A clogged vent pipe
- D. Low water pressure in the main supply line
Why: The flapper seals the opening between the tank and bowl. When it wears out, becomes warped, or fails to seat properly, water continuously leaks into the bowl, causing the toilet to run. Replacing the flapper is an inexpensive, common fix.
Q2. Where is the shutoff valve for a toilet usually located?
- A. Inside the toilet tank
- B. On the wall or floor behind the toilet ✓
- C. Under the toilet seat
- D. Inside the bathroom sink cabinet only
Why: Most toilets have a shutoff valve on the supply line, typically on the wall or floor directly behind the toilet. Turning it clockwise shuts off water to the toilet, which is essential before making repairs to avoid flooding.
Q3. What should you do before opening a toilet tank to perform a repair?
- A. Pour bleach into the bowl
- B. Turn off the water supply and flush to drain the tank ✓
- C. Remove the toilet seat
- D. Wait for the tank to fill completely
Why: Turning off the water supply stops new water from entering the tank, and flushing empties most of the remaining water. This prevents spills and makes components easier to access and work on safely.
Q4. What is the purpose of the fill valve in a toilet tank?
- A. To release air from the supply line
- B. To control water entering the tank and shut off when the tank is full ✓
- C. To drain waste from the bowl
- D. To regulate the temperature of flushing water
Why: The fill valve (ballcock) refills the tank after each flush and shuts off once the water reaches the proper level, which is typically controlled by a float or float cup. A faulty fill valve can cause running water or a low tank level.
Q5. If the water level in your toilet tank is too low and the toilet flushes weakly, what is a likely cause?
- A. The wax ring has failed
- B. The fill valve is misadjusted or failing ✓
- C. The toilet bowl is cracked
- D. The floor flange is loose
Why: A weak flush with low tank water often points to a misadjusted or failing fill valve that is not refilling the tank to the correct level. Adjusting the float or replacing the fill valve typically resolves the issue. The wax ring and floor flange relate to leaks at the base, not tank water level.
Module 7
Module 7: Preventing Freezing and Water Damage
Preventing Freezing and Water Damage
Knowledge check
Q1. At what outdoor temperature range are pipes most at risk of freezing?
- A. Above 50°F (10°C)
- B. Below 20°F (-7°C) for an extended period ✓
- C. Between 45°F and 50°F (7°C to 10°C)
- D. Only when temperatures drop below 0°F (-18°C)
Why: Pipes are at serious risk when temperatures stay below about 20°F (-7°C) for several hours, especially in uninsulated areas like crawl spaces, garages, and exterior walls. Freezing can occur well above 0°F if exposure is prolonged or the pipes are poorly protected.
Q2. Which of the following is an effective way to protect exposed pipes in an unheated area?
- A. Wrapping them in foam pipe insulation sleeves ✓
- B. Painting them with a thick coat of latex paint
- C. Storing towels loosely around them without any covering
- D. Leaving cabinet doors closed under the kitchen sink
Why: Foam pipe insulation sleeves slow heat loss and provide a protective barrier against cold air. Paint and loose towels offer little insulation, and closed cabinet doors do not allow warm room air to reach the pipes.
Q3. What should you do if you suspect a pipe has frozen but water is not yet flowing from the faucet?
- A. Pour boiling water directly on the pipe
- B. Use a propane torch to thaw it quickly
- C. Keep the faucet open and gently apply heat with a hair dryer or heating pad, starting near the faucet and working toward the frozen section ✓
- D. Wait for the pipe to thaw on its own without opening the faucet
Why: Keeping the faucet open lets meltwater escape and relieves pressure, which helps prevent a burst. Gentle heat applied from the faucet end toward the blockage is safe. Open flames and boiling water can damage pipes or cause fires, and waiting without opening the faucet can lead to pressure buildup.
Q4. Before leaving your home for an extended winter vacation, which step best helps prevent water damage from freezing?
- A. Turning off the main water supply, draining the system, and keeping the heat set to at least 55°F (13°C) ✓
- B. Turning the heat off completely to save energy
- C. Leaving all faucets dripping slowly
- D. Setting the thermostat to 80°F (27°C) to be safe
Why: Shutting off and draining the water supply removes the water that could freeze and burst pipes, while maintaining a minimum temperature of about 55°F keeps the interior warm enough to protect remaining plumbing. Turning off heat entirely is a common cause of frozen pipes, and dripping faucets alone are not reliable protection.
Q5. Where in a home are pipes most likely to freeze?
- A. In the middle of a heated basement
- B. Inside a heated bedroom closet against an interior wall
- C. In exterior walls, unheated crawl spaces, and garages ✓
- D. Along the ceiling of a heated kitchen
Why: Exterior walls, crawl spaces, and garages are often poorly insulated and may lack consistent heat, making them the highest-risk areas. Pipes in interior, heated spaces are much less likely to freeze.