Interpretation and Sequence of Controls of Residential Controls 080204bC

Question 1

What is the high limit control setting on a fan control switch?

Answer 1

180°F to 200°F

Question 2

Generally, what are the fan on and fan off temperature setting on a fan control?

Answer 2

Fan ON 120°F to 140°F

Fan OFF 90°F to 100°F

Question 3

What is the proper differential setting between fan ON setting and fan OFF setting on a fan control?

Answer 3

30°F to 40°F

Question 4

Larger heating units may require what kind of gas valve?

Answer 4

Step open gas valve

Question 5

Low voltage thermostat wire must be a minimum of what type?

Answer 5

No. 18 AWG plastic coated wire

Question 6

What kind of switch is a combustion air prove switch?

Answer 6

Normally open single pole single throw

Question 7

Depending on the appliance, one end of the sensing tube on a combustion air prove switch will be positioned to sense what?

Answer 7

Negative or positive pressure

Question 8

How does a hot surface igniter operate?

Answer 8

Low resistance value and is normally powered by line voltage

Question 9

What is the surface temperature of an operating hot surface igniter?

Answer 9

1800°F

Question 10

What are the Y, G and C controls on a furnace control board?

Answer 10

Y = cooling

G = fan

C = common (no batteries needed)