Question

What causes the little pops and ticking that can be heard in some furnaces before the blower comes on?

Select one:
O A. Small concentrated pockets of gas that explode
O B. Mechanical rattles from an unbalanced indoor blower
O C. Expansion of the heat exchanger as it heats up
O D. Small quantities of water in the gas

Answer 1

C

The answer is expansion of the heat exchanger as it heats up because of the change in temperature.