Author Question: The sequence of operation of a high-efficiency furnace is ________. A) the thermostat calls for ... (Read 52 times)

audragclark · **on:** Jul 26, 2018

The sequence of operation of a high-efficiency furnace is ________.

A) the thermostat calls for heat, the pilot is established, the combustion fan turns on, the main burner comes on
B) the thermostat calls for heat, the combustion fan turns on, the pilot is established, the main burner comes on
C) the thermostat calls for heat, the pilot is established, the main burner comes on, the combustion fan turns on

Question 2

If the main heating coils of an electric furnace are not heating up, you should suspect that ________.

A) the system has an open fuse, the contacts of the first sequencer are not closed, or the main heating element is open
B) the fan switch contacts are not closed or the fan switch is faulty
C) the coil of the fan relay is open or the fan relay contacts are faulty