Heating Flashcards
The heating element found in electric forced air furnaces is typically made from
Nichrome
An electric heat system operating with a low voltage thermostat would have the heat relay wired in series with the
Thermostat heat anticipator
Identify the safety found in electric duct heating systems
Interlock
Contactors and _________ are commonly used to control the operation of the electric resistance heaters in electric furnaces
Sequencer
The U.S. Federal Trade Commission requires manufactures to provide an annual fuel utilization efficiency rating (AFUE). AFUE ratings are for
the benefit of
The consumer
A high efficiency gas furnace utilizing hot surface ignition (HIS) will enter into lockout mode if ignition is not detected
4 to 11 seconds
High efficiency furnaces use plastic vent piping because
Acidic flue gases
Lower flue temperatures
Condensation of flue gases
A technician uses which instrument to measure gas service and manifold pressure?
Water manometer
When servicing the ignition transformer of an oil furnace correct secondary voltage would be
10,000 Volts
When servicing the oil burner that repeatedly locks out, the technician tests the Cad Cell. In the presence of light the correct OHM reading should be
600 to 1000 OMHS
A standard oil burner nozzle identified as 80 degrees of angle and 1.00 GPH would deliver approximately how many BTUs per hour?
140,000 BTUs
Centrifugal pumps used in hydronic heating are considered non-positive displacement pumps because
They do not add significant pressure to the system
In a typical residential/light commercial hydronic heating system the expansion tank
Provides space for the heated water to expand
A residential hydronic heating system using three zone valve controls (rated 24 Volt, .50 amp each) would require a control transformer rated at
40VA
When installing a hydronic heating system the use of slow opening/closing zone valves allows for
Zone operation without water hammering
