Water Heater Test Prep

Question 1

Why is it important to replace a GAS BURNER ASSEMBLY?

Answer 1

-bad burners will blow your heat exchanger
- heat exchangers are expensive
- bad burner = #1 reason for heat exchanger failure

Question 2

Why is it important to replace SPARK IGNITERS?

Answer 2

• bad igniter will cause improper combustion
• result in flame rollout or delayed ignition

Question 3

Why is it important to replace THERMOCOUPLE/ FLAME SENSOR?

Answer 3

-bad flame sensor is very inefficient
- can cause short cycling and damage igniters, switches and motors

Question 4

Why is it important to replace a GAS VALVE?

Answer 4

• faulty gas valve is hazardous and reduces efficiency
• gas valves with flow through/ out of calibration can do irreparable damage

Question 5

Why is it important to replace INDUCER MOTOR ASSEMBLY?

Answer 5

• combustion motor is the first component to start when heat is applied
• failure means unit cannot run and part must be ordered in due to specific OEM

Question 6

Why is it important to replace a PRESSURE SWITCH?

Answer 6

• pressure switches are a safety device
  -prevents sudden no heat situation

Question 7

Why is it important to replace TEMPERATURE/ PRESSURE RELIEF VALVE?

Answer 7

• pressure relief valve is a safety device
• bad pressure relief valve is against code and is extremely dangerous

Question 8

How does a water heater work?

Answer 8

-cold water pipe brings water in to be heated at bottom of tank
-hot water rises to the top to be removed on demand
-continuously heating water

Question 9

How does a tankless water heater work?

Answer 9

• heated instantly without storage tank
  -hot water faucet on , cold water flows through heat exchanger
• heated by natural gas or electric

Question 10

What does a gas burner assembly do?

Answer 10

-responsible for heating water in the tank
- blends air and gas to make efficient blue flame ( little CO)

Question 11

What parts does a gas burner assembly consist of ?

Answer 11

• gas control valve
  -pilot light assembly
  -main burner
  -thermocouple

Question 12

What is CO?

Answer 12

-Carbon monoxide

Question 13

The more orange the flame , the more what is produced?

Answer 13

Carbon monoxide (CO)

Question 14

What happens if you don’t replace a GAS BURNER ASSEMBLY?

Answer 14

• dirt/soot buildup
  -orange /unclean flame

Question 15

What does a SPARK IGNITOR do ?

Answer 15

• ignites flame instantly to prevent delayed ignition
• creates electrical spark that ignites burners

Question 16

How does a HOT SURFACE IGNITOR (HSI) work ?

Answer 16

• sending low voltage but high current electricity through ignitor

Question 17

What temperature must a HOT SURFACE IGNITOR reach to ensure instant ignition?

Answer 17

2400 °F

Question 18

What parts are ignition systems paired with ?

Answer 18

Flame rectification system - thermocouple or flame sensor

Question 19

What happens if you don’t replace SPARK IGNITOR/ HSI?

Answer 19

• crack Or break
• improper ignition

Question 20

What is a THERMOCOUPLE/ FLAME SENSOR?

Answer 20

• device used to control gas flow in water heaters

Question 21

How does a FLAME SENSOR work?

Answer 21

-Grounds itself in flame and ensures burner is lit and burning
- if no flame , rod cannot ground and won’t ignite

Question 22

How does a THERMOCOUPLE work?

Answer 22

-2 dissimilar metals
- when metals meet and are heated it creates millivolts
- voltage provides power to hold pilot light valve open

Question 23

How many millivolts does a THERMOCOUPLE need to hold open the pilot light valve?

Answer 23

25-30

Question 24

What happens if you don’t replace a THERMOCOUPLE/ FLAME SENSOR?

Answer 24

hinders the sensor

Question 25

What is a gas valve?

Answer 25

Temperature and gas control on natural gas water heater

Question 26

What does a GAS VALVE do?

Answer 26

Responsible for opening and closing the incoming gas

Question 27

What does a gas valve's thermal wall do ?

Answer 27

Senses temperature of the water inside water heater

Question 28

What happens if the temperature of the water is below desired setting indicated by the gas valve ?

Answer 28

Feeds gas through burner table into burner chamber by opening gas line

Question 29

What happens if water touches a gas valve ?

Answer 29

It must be replaced, by code

Question 30

What can flow though be caused by ?

Answer 30

Damage or dirt

Question 31

What does INDUCER MOTOR ASSEMBLY DO?

Answer 31

- draws air into burner and exhaust out the flue - closes a pressure switch to signal proper airflow as air flows through

Question 32

What does a pressure switch do?

Answer 32

Used to verify operational conditions are met

Question 33

What can cause pressure switch failure?

Answer 33

A plugged drain

Question 34

What does a TEMPERATURE/ PRESSURE RELIEF VALVE do?

Answer 34

Releases excess heat or pressure

Question 35

How often must TEMPERATURE/ PRESSURE RELIEF VALVES be tested ?

Answer 35

Every year

Question 36

What must you do before testing TEMPERATURE/ PRESSURE RELIEF VALVE?

Answer 36

Warn customer it could be defective

Question 37

What are the 3 types of water heaters?

Answer 37

-Natural vent -power vent -hybrid

Question 38

What are the 4 moving parts of a TANKLESS?

Answer 38

-Fan -mixing valve -damper -gas valve

Question 39

What is a NATURAL DRAFT water heater?

Answer 39

- traditional heater with draft good -uses gravity to exhaust gas

Question 40

What is a POWER VENT water heater?

Answer 40

Has fan on top that pushes gas out using PVC pipe

Question 41

What is a HYBRID water heater?

Answer 41

Utilizes electric heat and a built in heat pump to heat water

Question 42

What type of heaters do boilers have ?

Answer 42

Stainless steel firetube

Question 43

What are the 2 types of boilers?

Answer 43

VX and CX

Question 44

What is a VX boiler used for ?

Answer 44

-space heating

Question 45

What is a CX boiler used for

Answer 45

- space heating -domestic hot water