Troubleshooting & Diagnostics Flashcards
7 cards from real PC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Troubleshooting & Diagnostics flashcards as text
A customer reports that their water heater produces hot water for only a few minutes before it turns cold. What is the MOST likely cause?
Answer: Faulty dip tube allowing cold and hot water to mix
A broken or missing dip tube allows incoming cold water to mix directly with hot water near the top of the tank, drastically reducing hot water supply time.
A floor drain is emitting sewer gas odors intermittently. The FIRST diagnostic step should be to:
Answer: Pour water into the drain to refill the trap
An evaporated P-trap is the most common cause of intermittent sewer gas odors from floor drains, and pouring water restores the water seal immediately.
A pressure gauge on a well pump system reads normal when the pump is off but drops significantly when any fixture is opened. This indicates:
Answer: Waterlogged pressure tank
A waterlogged pressure tank has lost its air cushion, causing rapid pressure drop when water is drawn because the tank holds almost no reserve.
A gas water heater pilot light keeps going out repeatedly. After relighting, it extinguishes within seconds. The MOST likely faulty component is the:
Answer: Thermocouple
A defective thermocouple fails to sense the pilot flame and signals the gas valve to close, extinguishing the pilot within seconds of lighting.
During a visual inspection, a plumber notices the cold water pipe at a water heater is warm to the touch when no hot water is being used. This condition is called:
Answer: Thermal siphoning / convection loop
Thermal siphoning occurs when hot water naturally rises and circulates backward through cold supply lines due to convection when no check valve is present.
A kitchen faucet drips from the spout when turned off. The faucet is a cartridge-type single-handle. The MOST likely cause is:
Answer: Failed cartridge seals
In cartridge faucets, a worn or damaged cartridge with failed internal seals is the most common cause of dripping from the spout.
A homeowner complains of banging noises in the pipes when the washing machine valve closes. This phenomenon is known as:
Answer: Water hammer
Water hammer is caused by a sudden stop of fast-moving water creating a pressure shockwave that produces a loud banging noise in the pipes.