Furnace Start Up

Question 1

Furnace must be wired electrically and ground according to what? In the absence of that you should use?

Answer 1

Canadian electrical code (CEC), or CSA C22.1

Question 2

The blower motor should be checked for.

Answer 2

Shipping blocks or brackets removed, motor mount checked for tightness

Question 3

3 ways to check for a gas leak

Answer 3

Test dial on gas meter
Commercial leak detector (soapy water solution)
Electronic leak detector

Question 4

How to check gas leak with test dial

Answer 4

Turn off gas to all appliances minus the one you’re working on, go to gas meter, locate test dial mark where dial is, wait ten minutes see if it moved.

Question 5

What do electronic leak detectors detect

Answer 5

Detects the mercaptin.

Question 6

All venting systems are required to first follow

Answer 6

Appliance manufacturers installation instructions.

Question 7

All venting must match the what?

Answer 7

The category of furnace it is intended

Question 8

All metal vent and vent connectors must be

Answer 8

ULC approved and adhere to b149 gas code

Question 9

Metal vent connector material must be installed so that there is no

Answer 9

Dips or sags with all joints fully inserted and locked together.

Question 10

All plastic vent must be certified to

Answer 10

ULC S636 and must be clearly marked.

Question 11

Excessive air leakage could cause what

Answer 11

A shortage of warm air in certain rooms

Question 12

On new construction it is good practice to?

Answer 12

Inspect entire heating ventilation and air conditioning.

Question 13

What do you match the heat anticipator to?

Answer 13

The amperage of the 24 volt control circuit.

Question 14

How to set a single stage Manifold pressure

Answer 14

Must turn off gas at the gas cock first and connect the manometer to the outlet pressure port on the gas valve

Question 15

Failure to set the air temp rise can result in?

Answer 15

Reduced furance life

Question 16

Where is the tempature rise readings taken from?

Answer 16

The supply air plenum but not in direct view of heat exchanger

Question 17

What must you do if temp rise is to low or to high

Answer 17

If to low decrease fan speed if to high increase fan speed.

Question 18

What are the speeds on a pcm used for

Answer 18

Low is continuous fan op
Medium is for heating mode
High is for cooling

Question 19

How to change speed in an ECM

Answer 19

Changing a series of small switches “dip sticks”

Question 20

How to test a high limit

Answer 20

Remove motor lead from heating terminal and placing it on a park terminal ( terminal that is never energized)

Question 21

In sequence of operation what is considered the pre purge and how long is it

Answer 21

1.Call for heat R&W closes
2.relay coil energized, closes contacts for inducer motor
3.pressure switch closes
Takes 15-45 seconds

Question 22

In the sequence of operation what steps are considered the trial for ignition.

Answer 22

1. Relay coil energies, closes contacts for hsi
   2.relay coil energies, closes contact for gas valve
   3.burners ignite
   4.flame proves through rectification
   5.hsi de-energizes

Question 23

How long after the gas valve energized does it take for the main blower motor to start

Answer 23

30-45 seconds

Question 24

Where would you find the primary limit switch

Answer 24

Next to the heat exchanger

Question 25

What type of venting is used for a condensing gas appliance

Answer 25

Bh venting