Fuel oil is a liquid fossil fuel that consists primarily of carbon, hydrogen, and moisture.

A(n) ___ shuts the burner OFF in the event of a low water condition.

Any maintenance and cleaning of the low water fuel cutoff must be done while there is no pressure on the boiler.

An electrical safety policy must include the use of PPE.

A nonreturn valve is a type of globe valve that allows a boiler to be cut in on-line automatically when the boiler pressure is at or above the header pressure and allows the boiler to be taken off-line automatically if the pressure in the boiler drops below the header pressure.

Makeup water is untreated and contains some scale-forming salts that can affect boiler heating surfaces.

The primary regulatory requirements related to electrical safety come from NFPA 70E®, Standard for Electrical Safety in the Workplace.

The ___ of a modulating burner is the ratio of the maximum firing rate to the minimum firing rate.

A nonreturn valve is a type of globe valve that allows a boiler to be cut in on-line automatically when the boiler pressure is at or above the header pressure and allows the boiler to be taken off-line automatically if the pressure in the boiler drops below the header pressure.

Cooling systems follow a cycle where the refrigerant moves through the five main system components.