Question 1

Temperature and pressure (T&P) relief valves shall be installed on:

Accepted Answer

IPC 504.4 requires safety relief valves (T&P) on all storage-type water heaters operating above atmospheric pressure.

Question 2

The discharge piping from a T&P relief valve must terminate:

Accepted Answer

IPC 504.6 requires the discharge pipe to terminate not more than 6 inches above the floor or waste receptor to prevent splashing and scalding.

Question 3

A water heater pan is required when:

Accepted Answer

IPC 504.7 requires a pan where water heaters are installed in locations where leakage of the tank or connections will cause damage.

Question 4

The minimum size of the drain pipe for a water heater pan is:

Accepted Answer

IPC 504.7.1 states the pan drain shall be not less than 1 inch in diameter.

Question 5

T&P relief valves must be set to open at a maximum temperature of:

Accepted Answer

IPC 504.5 requires the temperature relief element to be set at 210°F.

Question 6

The discharge pipe from a relief valve shall NOT be:

Accepted Answer

IPC 504.6 prohibits trapping the discharge pipe, as water could freeze or stagnate, blocking the safety relief path.

Question 7

Water heaters installed in an attic must have a passageway not less than ___ inches high and ___ inches wide.

Accepted Answer

IPC 502.3 requires a passageway to appliances in attics to be at least 30 inches high and 22 inches wide, extending no more than 20 feet.

Question 8

Bottom-fed water heaters require a ___ valve to prevent siphonage if the supply pressure drops.

Accepted Answer

IPC 504.2 requires bottom-fed water heaters to have a vacuum relief valve to prevent the tank from collapsing or elements burning out due to siphonage.

Question 9

The maximum setting for the pressure relief valve on a water heater is:

Accepted Answer

IPC 504.4.1 states the pressure relief valve shall be set at the rated working pressure of the water heater plate, typically 150 psi.

Question 10

Can the discharge piping from a T&P valve be directly connected to the drainage system?

Accepted Answer

Direct connection is prohibited to prevent sewage backup into the potable water system. An air gap is required.

Question 11

A full-open valve (shutoff) shall be installed on the:

Accepted Answer

IPC 503.1 requires a shutoff valve on the cold water supply to allow for service.

Question 12

Where a check valve or backflow preventer is installed on the water supply, a(n) ___ is required.

Accepted Answer

IPC 607.3 requires a thermal expansion tank when the system is 'closed' by a check valve or backflow preventer, to absorb pressure increases from heating water.

Question 13

The discharge pipe from a T&P valve must be:

Accepted Answer

IPC 504.6 states the discharge piping shall be the same size as the relief valve outlet (usually 3/4 inch).

Question 14

Fuel-fired water heaters shall not be installed in a:

Accepted Answer

IPC 502.5 / IFGC 303.3 prohibits fuel-fired water heaters in sleeping rooms or bathrooms unless they are direct-vent systems receiving all combustion air from outdoors.

Question 15

What material is NOT allowed for T&P discharge piping?

Accepted Answer

Standard PVC is not rated for the high temperatures (210°F) that a T&P valve releases. CPVC, Copper, or Galvanized Steel must be used.

Question 16

Under the UPC, the water heater strap for earthquake protection in the lower one-third of the tank must be at least ___ inches above the controls.

Accepted Answer

UPC 507.2 requires strapping in the upper 1/3 and lower 1/3. The lower strap must be at least 4 inches above the controls.

Question 17

The thermostat on a residential water heater should be set to ___ to prevent scalding while minimizing Legionella growth.

Accepted Answer

Standard practice and some codes recommend storing at 140°F to kill bacteria, but using a mixing valve to deliver 120°F to fixtures.

Question 18

A water heater drain valve shall be installed:

Accepted Answer

IPC 503.2 requires a drain valve at the bottom of the tank for emptying and sediment removal.

Question 19

If a water heater is installed in an attic, the passageway must have continuous solid flooring not less than ___ inches wide.

Accepted Answer

IPC 502.3 requires a passageway with continuous solid flooring at least 24 inches wide leading to the appliance.

Question 20

When using a tankless water heater, the sizing of the gas line is often:

Accepted Answer

Tankless heaters require a very high BTU input (often 199k BTU) to heat water instantaneously, usually requiring a larger gas line.

Question 21

Dielectric unions are required on water heater connections if:

Accepted Answer

IPC 605.24 requires dielectric separation to prevent galvanic corrosion when dissimilar metals are joined.

Question 22

A relief valve discharge pipe shall terminate atmospherically and not be:

Accepted Answer

IPC 504.6 states the discharge pipe shall not be threaded on the discharge end to prevent capping or plugging by unauthorized persons.

Question 23

In the UPC, discharge piping from a T&P valve may terminate:

Accepted Answer

UPC 608.5 generally requires T&P discharge to terminate outside the building (unless structural conditions make it impossible). IPC allows floor discharge inside.

Question 24

For commercial installations, water heaters shall be marked with:

Accepted Answer

IPC 501.8 requires appliances to be labeled with manufacturer info, input rating, and working pressure.

Question 25

Expansion tanks on potable water systems must be sized based on:

Accepted Answer

IPC 607.3 sizing depends on the capacity of the water heater and the supply pressure.

Question 26

Which of the following is NOT a required clearance for a water heater?

Accepted Answer

While vent clearance is required, there is no generic '12 inch ceiling clearance' rule for the unit itself unless specified by the manufacturer or vent tables.

Question 27

Water heaters using the 'side-arm' heating method utilize:

Accepted Answer

Side-arm heaters heat water in a separate loop (heat exchanger) and store it in a tank.

Question 28

Solar water heating systems must comply with:

Accepted Answer

Solar thermal systems are covered in IPC Chapter 14 (in older codes) or referenced Solar Energy Provisions.

Question 29

T&P valves on water heaters installed in attics must discharge:

Accepted Answer

Discharge must go to a safe place of disposal. Discharging *into* the pan is generally prohibited because the pan drain may not handle the high-pressure blow-off. It must go to the receptor or outdoors. [Note: Some local codes vary, but model code says 'waste receptor or outdoors'].

Question 30

Draft hoods on gas water heaters are designed to:

Accepted Answer

Draft hoods decouple the appliance from the vent stack, preventing backdrafts from affecting the burner.

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