Which type of furnace can operate to produce either full heat output or produce at a fixed level that is less than full heat?
A Category I furnace is a ____ furnace.
A Category I furnace is a ____ furnace.
A combination gas valve is used to replace separate furnace…
A combination gas valve is used to replace separate furnace components, such as a ____.
Which of the following statements regarding hot-surface igni…
Which of the following statements regarding hot-surface ignition (HSI) systems is false?
A furnace that can vary its heat output along a scale that m…
A furnace that can vary its heat output along a scale that may range from 40% to 100% capacity is a(n) ____ furnace.
A furnace with an AFUE rating between 90% and 97% is a ____…
A furnace with an AFUE rating between 90% and 97% is a ____ gas furnace.
Which of the following statements regarding rollout switches…
Which of the following statements regarding rollout switches is true?
As excess air increases, ____.
As excess air increases, ____.
A(n) ____ humidifier uses its own heat source to create stea…
A(n) ____ humidifier uses its own heat source to create steam.
A device that may be used to detect combustion blower operat…
A device that may be used to detect combustion blower operation is a(n) ____.