AGA XH0205 : 2002

I. INTRODUCTION
      CHAPTER REVIEW
II. CONTROLS AND THEIR FUNCTIONS
      Need for Controls
      Manual and Automatic Operations
      Basic Elements of Automatic Controls
      Evolution of Automatic Controls
      CHAPTER REVIEW
III. MANUAL CONTROL OF GAS APPLIANCES
      Electric Switches
      Orifices
      Manual Adjustment of Controllers
      CHAPTER REVIEW
IV. PHYSICAL PRINCIPLES USED IN CONTROLS
      Thermal Expansion of Gases, Liquids and Metals
      Electrical Heating of a Resistive Element
      Change of Electrical Resistance with Temperature
      Thermoelectric Effect
      Electromagnetism and Solenoids
      Change in Shape of Coils from Internal Pressure Changes
      CHAPTER REVIEW
V. SENSING DEVICES
      Temperature Responsive Devices
        Bimetals
        Unevenly Heated Shapes
        Rod and Tube Sensors
        Hydraulic and Pneumatic Bulbs
        Electrical Resistance Coils, RTD's and Thermistors
        Fusible Links
      Pressure Responsive Devices
        Metallic Bellows and Diaphragm Sensors
        Coiled Metallic Tubing
        Flow Sensing Devices
        Liquid Level Sensors
        Float Type
        Electrical Contact Type
        Rotation Sensors
      Flame Sensors
        Thermocouple
        Bimetal
        Hydraulic or Mercury Vaporization Type
        Optical Systems
        Flame Rectification
      CHAPTER REVIEW
VI. ACTUATION OF CONTROLS
      Self-Powered Devices
        Use of Motion Due to Expansion or Warping
        Use of Generated Pressure
        Use of Generated Electrical Current
      Externally-Powered Devices
      CHAPTER REVIEW
VII. AUTOMATIC CONTROLS
      Thermostats
        Hydraulic Thermostats
        Rod and Tube Thermostats
        Bimetal Thermostats
        Heating/Cooling Thermostats
        Automatic Offset Thermostats
      Automatic Gas Valves
        Diaphragm Automatic Valves
        Solenoid Valves
        Heat Motor Automatic Valves
        Hot-Wire Valves
        Motorized Valves
      Limit Controls
        Thermostatic Limit Controls
        Low Liquid Level Shutoff Controls
      Gas Pressure Regulators
        Conventional Gas Pressure Regulator Operation
        Servo Pressure Regulators
        Two-Stage Regulators
        Types of Gas Pressure Regulators
        Capacities of Gas Pressure Regulators
        Location and Position
      Combination Controls
      Accessories
        Automatic Vent Dampers
        Motors
        Fans or Blowers
        Pumps
        Transformers
        Pilot Gas Filters
      Miscellaneous Controls
        Time Switches
        Draft Controls
      CHAPTER REVIEW
VIII. IGNITION SYSTEMS
      Automatic Pilots
        Pilot Burners
        Safety Shutoff by Automatic Pilots
        Means of Ignition
        Two-Stage Automatic Pilot Systems
      Oxygen Depletion Sensing (ODS) Pilots
      Pilot Relight Systems
      Intermittent Ignition Devices
        Direct Spark Ignition
        Hot Surface Ignition
      CHAPTER REVIEW
IX. APPLICATION TO APPLIANCES
      Ranges
        Top-Burner Controls
        Oven and Broiler Burner Controls
        Self-Cleaning Oven Controls
        Ranges Features and Accessories
      Automatic Water Heaters
        Automatic Storage Heaters
        Automatic Circulating Tank Type Heaters
        Instantaneous Water Heaters
        Swimming Pool Heaters
      Central Heating Systems
        Steam Heating
        Hot Water (Hydronic) Heating
        Warm Air Heating
        Potable Water-Source Space Heating Systems
        Room Thermostats
        Humidity Controls
        Conversion Burners
        Wiring Considerations
      In-Space Heating Appliances
        Outdoor Heating
      Clothes Dryers
        Ignition Systems
        Dryness Sensing
        Timers
        Temperature Limit Controls
        Two-Level Dryer Burners
        Air Flow Control
        Motor Control
      Refrigeration
        Refrigerator Burners
        Pressure Regulators
        Thermostats
        Defrost Systems
      Incinerators
        Ignition of Refuse
        Controls
      Air Conditioners
        Ignition
        Cooling Thermostats
        Pilot and Main Burner Valves
        Venting
        Sail Switch for Flue Gas
        Limits
        Special Considerations
      CHAPTER REVIEW
X. MAINTENANCE AND REPAIR OF CONTROLS
      Preventive Maintenance
      Summary Comments
      CHAPTER REVIEW
REFERENCES SOURCES
GLOSSARY
ANSWERS TO CHAPTERS REVIEW

Includes description of gas appliance controls and their functions.