NATE - Gas & Heat 139 Questions with Complete Solutions

NATE - Gas & Heat 139 Questions with Complete Solutions 3/8 to 1/2 inch of the end of the thermocouple: - Correct Answer Should be enveloped by the pilot flame A "cross break" made on all sides of any rectangular section of metal duct will: - Correct Answer Increase rigidity and reduced vibration A control string is defined as two or more switch contacts connected in a circuit, or set of circuits, to control a load. In order to troubleshoot a load controlled by a control string, the technician must first: - Correct Answer Check for proper voltage applied across the load A customer complains the unit is "blowing cold air". The technician determines that the problem occurs at the end of the heating sequence. The furnace used an electronic integrated blower control. - Correct Answer The likely problem with the system is the blower off delay is set too long. A customer has concerns about CO in their home. Many of their reported symptoms indicate there may indeed be a CO problem but on each trip the technician makes to check their home the technician finds normal CO levels. - Correct Answer CO detector reader/recorder would be appropriate to use for determining if a problem truly exists. A damaged section of double wall vent pipe is to be replaced with a section produced by a different manufacturer: - Correct Answer The installer should check the new section for compatible locking joints A dirty or clogged air filter in an operating gas furnace can cause an: - Correct Answer Increase temperature rise A furnace is inoperative because of a failure in the ignition sequence at the flame proving stage. To check the flame proving circuit the technician would: - Correct Answer Connect a microampmeter set to DC microamps in the sensor circuit and operate the furnace. A gas clothes dryer can interfere with the operation of a nearby natural draft gas furnace with an atmospheric burner by: - Correct Answer Stealing combustion air preventing complete fuel burning