What a Technician Should Know

Section 2 - Gas Furnaces

19. On a thermostat, terminals Y G R W are present. What does Y stand for?*

Fan24v/PowerCoolingHeating

20. On a thermostat, terminals Y G R W are present. What does G stand for?*

Fan24v/PowerCoolingHeating

21. On a thermostat, terminals Y G R W are present. What does R stand for?*

Fan24v/PowerCoolingHeating

22. On a thermostat, terminals Y G R W are present. What does W stand for?*

Fan24v/PowerCoolingHeating

23. What is the voltage coming into the line side of a transformer for a furnace?*

0v24v110v or 120v240v

24. What is the most important role a service tech has in a repair situation:*

Keeping the ticket amount down to avoid an unhappy customerTo educate the customer on what failed, why it failed and what their options areCompleting repairs as fast as possible to keep company cost downNone of the above

25. Carbon monoxide in a gas fired furnace is:*

26. Carbon monoxide is measured in:*

27. What determines where the dip switches are set on a Lennox variable speed furnace?*

The size of the flue pipeThe number of supplies and returns in the home.The tonnage of the Air ConditioningFilter sizeThe number of burners the furnace has

28. If a furnace has a temperature rise rating of 40 deg -65 deg and your temperature rise is 80 deg, this would most likely mean?*

29. You have a condenser unit on the roof of a 4 story building and the furnace and A-coil are in the basement. What do you need to do?*

Use the stairs or a ladder to access the condenserAdd a J trap to the line setAdd a V trap in the basementMake sure both the Liquid and Suction Lines are insulatedAdd a pump to the Liquid Line to aid the refrigerant back to the compressor

30. In a condensing gas furnace, the burners cycle intermittently on the inducer proving switch. What is a possible cause of the problem?*

31. On a spark ignition gas furnace, the spark ignites the pilot flame, but continues to spark and the main gas valve will not open. Why?*

32. You see signs of condensation and rust inside a heat exchanger. This can be caused by:*

What a Technician Should Know

Low Side / High Side

Section 4- Basic Electrical