Heating 1 & 2 Final

Question 1

All of the following are problems found on gas piping except

Answer 1

Excess Pressure

Question 2

The ASHI standards require that we report on the life expectancy of furnaces

Answer 2

False

Question 3

Bonding the gas piping to the supply piping of the house means

Answer 3

Any stray electrical current will not cause arcing, which otherwise could ignite the gas. Assuming the supply water piping is grounded, bonding the gas piping to it prevents an electrical buildup within the gas piping that could lead to arcing, which might ignite the gas.

Question 4

Common condensate problems on high efficiency furnaces include all of the following except.

Answer 4

No automatic air vent on condensate lines. Condensate lines do not need an automatic air vent.

Question 5

Common heat-exchanger problems on mid and high efficiency furnaces include all of the following except

Answer 5

Vibration is not a common heat exchanger problem.

Question 6

A common temperature rise across a conventional furnace is

Answer 6

The common temperature rise is 70°F - 100°F

Question 7

A common temperature rise across a modern high efficiency gas furnace is

Answer 7

The answer is 35°F to 70°F The temperature rise for a high efficiency furnace is quite low. Even for conventional furnace the temperature rise is 70°F - 100°F

Question 8

Direct vent heating systems take

Answer 8

Combustion air from outside the dwelling.

Question 9

The exhaust flue on a mid efficiency furnace should have a six inch combustible clearance. On a high efficiency furnace exhaust flue, the required clearance is

Answer 9

Zero Inches - No combustible clearances are required for high efficiency furnace exhaust flue.

Question 10

The exhaust from a high efficiency gas furnace terminates underneath an enclosed deck. Is this a concern?

Answer 10

Yes, the exhaust gases will rot the deck

Question 11

The exhaust gas temperature from a high efficiency gas furnace is typically?

Answer 11

100°F to 150°F

Question 12

The fan/limit switch will typically turn the blower on at

Answer 12

The fan / limit switch typically turns the blower on at 150°F In some modern applications it can be as low as 120°F

Question 13

Flame roll out would never be caused by

Answer 13

Flashback or flame roll out is never caused by a cracked heat exchanger.

Question 14

The flame wavers over one blower in a gas furnace when the blower comes on, what is likely the cause of this?

Answer 14

A wavering flame probably indicates an unstable draft condition, which can be caused by a venting problem or a crack in the heat exchanger.

Question 15

Heat exchanger failure in a conventional efficiency furnace may lead to all of these except.

Answer 15

Soot build up on the burner side of the heat exchanger is not a cause of heat exchanger failure.

Question 16

Heat exchangers seperate the?

Answer 16

Combustion air from the house air.

Question 17

A heating thermostat located in the kitchen will tend to?

Answer 17

Because kitchens tend to be warmer than the rest of the house, placing a thermostat here will tend to keep the rest of the house cooler than desired.

Question 18

High-efficiency gas furnaces improve efficiency by?

Answer 18

High efficiency gas furnaces condense exhaust gases and reduce temperature rise across the heat-exchanger

Question 19

The high limit setting for a forced air furnace is typically?

Answer 19

The high limit setting is typically 200°F

Question 20

The homeowner has tucked the supply and return plenums up tight along a wood beam, are there concerns with this?

Answer 20

Yes the ducts are too close to the combustible wood.

Question 21

How much should a belt deflect when its under tension?

Answer 21

You should be able to push the belt in about 1 inch at the halfway point between the pullies

Question 22

If the anticipator setting is too low for the current from the gas valve, the house will overshoot?

Answer 22

Overshooting is an indicator that the setting is too high, not too low.

Question 23

The implication of improper slope on a exhaust flue from a high efficiency gas furnace is

Answer 23

Frost closure at the discharge.

Question 24

In a heating only climate, an uninsulated duct running through a garage will deliver what kind of air at the end of the duct.

Answer 24

Cool air.

Question 25

What is an anticipator, how is it set, and what are common problems associated with them?

Answer 25

Designed to fool the thermostat to shut off furnace early. It should be set to the current that the gas valve draws. (0.1 amps to 1.5 amps) If set to low - short cycling If set to high - rooms too warm.

Question 26

Vent connectors are also called what

Answer 26

Exhaust flues, c vents, vent pipes, stack pipes, flue pipes, chimney connectors, breechings

Question 27

Types of electronic ignition

Answer 27

intermittent pilot (IP), hot surface ignition (HSI) Direct spark ignition (DSI)

Question 28

Induced draft fans are also called what

Answer 28

Exhaust blowers, power vents, power venters

Question 29

All oil furnaces use what type of fan

Answer 29

Forced draft

Question 30

What are the product names of plastic venting on mid-efficiency furnaces (Banned in 1994)

Answer 30

Sel-Vent, Ultravent, Plexvent

Question 31

In an atmospheric gas burner the thermocouple does what?

Answer 31

The thermocouple senses the pilot flame

Question 32

What type of systems use hot water from a special type of hot water heater to heat the home?

Answer 32

Integrated Systems, Integrated Heating and Water Heating Systems

Question 33

What is a primary controller and what are a few other names for it?

Answer 33

it is an automatic safety device to shut off the burner if the flame is out. Primary relay, stack relay, flame sensor, fire-eye, photo-cell, cad cell