Column 1
The primary purpose of a hydronic expansion tank is to___________________.
Absorb water volume changes as it heats.
A pump relay is primarily used to:
Energize a circulator when there is a call for heat
In a typical forced-air system, ductwork is mainly used to
Deliver and return air between equipment and rooms
Which tool is MOST appropriate for verifying 24 VAC control voltage?
Digital multimeter set to AC volts
A typical residential thermostat “R” terminal generally represents
Common (C)
Which piping material is most commonly used for black iron threaded gas piping?
Steel (black iron)
A common symptom of low air flow across an A/C evaporator coil is
Ice formation on the coil or suction line
A heat pump in heating mode that blows cool air may indicate
Reversing valve stuck in cooling
In a hot water heating system, the component most associated with removing microbubbles/air is a(n):
Air separator/air scoop
One major reason to keep the boiler relief valve discharge unobstructed and piped properly is to
Prevent scalding and property damage during overpressure events
A Taco-style zone control panel/relay board is commonly used to
Control multiple zone circulators and manage end switches
A flow check valve (hydronic) is commonly used to
Prevent ghost flow/gravity circulation when the pump is off
Which is the BEST description of a zone valve?
A. valve that opens/closes flow to a heating zone
When checking for power on a gas furnace, the FIRST priority is to
Verify safe access and use proper PPE and meter settings
The purpose of a draft regulator (barometric damper) on many oil appliances is to
Maintain more consistent draft
A safe and correct action before testing live voltage in equipment is to
Confirm meter category rating and inspect leads
On a heat pump thermostat, the “O/B” terminal typically controls the:
Reversing valve
The “C” terminal on a furnace control board is usually the
24-volt common
In an oil burner combustion check, smoke number is used to evaluate
Soot/smoke in flue gases (air/fuel balance indicator)
In basic electrical troubleshooting, continuity testing should be performed
With power off and the circuit isolated when possible