Water Heaters and Hot Water Systems Flashcards
7 cards from real Master Plumber Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Water Heaters and Hot Water Systems flashcards as text
What type of anode rod is recommended for a water heater connected to a water softener system?
Answer: Aluminum-zinc combination anode rod
Aluminum-zinc anode rods are preferred for softened water because magnesium rods corrode too rapidly in the elevated-conductivity environment created by salt-based softeners.
Per the International Plumbing Code, what is the maximum hot water temperature permitted at bathing fixtures in healthcare facilities?
Answer: 110°F
The IPC limits hot water at healthcare bathing fixtures to 110°F to protect patients who may have reduced sensation, mobility, or reaction time from scalding injuries.
A tankless water heater must deliver 2.5 GPM with a 70°F temperature rise. Approximately how many BTU/hr must it produce?
Answer: 87,500 BTU/hr
BTU/hr = GPM × 60 min × 8.33 lb/gal × ΔT = 2.5 × 60 × 8.33 × 70 ≈ 87,465 BTU/hr.
According to the Uniform Plumbing Code, what is the maximum height above the floor or flood-level rim of a floor drain at which a T&P relief valve discharge pipe may terminate?
Answer: 6 inches
The UPC requires the T&P discharge pipe to terminate no more than 6 inches above the floor or drain flood-level rim so hot water discharges safely without risk of scalding nearby occupants.
What does the Energy Factor (EF) rating measure for a water heater?
Answer: The overall energy efficiency based on a simulated 24-hour use cycle
The EF rating compares the energy content of hot water delivered to total energy consumed over a standardized 24-hour test cycle, representing overall efficiency.
Which venting material is NOT approved for use as a connector on a Category I atmospheric gas water heater?
Answer: Flexible aluminum dryer duct
Flexible aluminum dryer duct is not listed for gas appliance venting because it cannot withstand the temperature and corrosion requirements for flue gas exhaust.
What is the minimum required slope for a T&P relief valve discharge pipe to ensure complete self-drainage?
Answer: 1/4 inch per foot
T&P discharge pipes must slope downward at a minimum 1/4 inch per foot so water drains completely and does not pool in the pipe between relief events.