A-1 Gas-Fired Appliances Introduction
On the job, under the supervision of a certified gasfitter, you may be required to install and service a variety of gas-fired appliances. This section is designed to familiarize you with some of the appliances you may encounter and provide a brief overview of their operational characteristics.
Learning Objectives
After completing the chapters in this section, you should be able to:
- Describe the appliance characteristics that impact the operational environment and installation of gas appliances.
- Describe various gas-fired appliances.
- Use manufacture and supplier documentation for gas appliances.
Terminology
The following terms will be used throughout this section. A complete list of terms for this section can be found in the Glossary.
- carbon monoxide (CO) sensor: A safety device that detects dangerous levels of carbon monoxide gas and may activate a shut-off mechanism on gas appliances. (Section A-1.2)
- certification organizations: Groups that check if products are made and work safely and correctly. They put special labels on products to show they meet safety rules. (Section A-1.3)
- concentric coaxial pipe: A type of pipe made of two pipes, one inside the other. The outer pipe carries air, while the inner pipe carries the fuel or exhaust, helping to safely vent gases while bringing in fresh air for combustion. (Section A-1.1)
- direct vent appliance: A sealed combustion gas appliance that draws air from outside for combustion and vents exhaust gases directly outside, improving safety and efficiency. (Section A-1.2)
- energy efficiency standards: Rules that set the minimum level of energy use for appliances, making sure they use energy in a smart way and help save power. (Section A-1.3)
- ENERGY STAR®: A program that identifies products meeting high-efficiency standards for energy use, helping consumers choose energy-saving appliances. (Section A-1.3)
- flammable vapour ignition resistant (FVIR): A safety design feature in gas water heaters that prevents the ignition of flammable vapours outside the combustion chamber. Especially important in areas like garages where flammable liquids may be stored. (Section A-1.2)
- heat output: The amount of heat a machine or appliance, like a water heater, can produce. It shows how much energy it transfers to heat things up. (Section A-1.3)
- hybrid tankless water heater: A type of tankless water heater equipped with a small buffer tank and a circulation pump. This design supports hot water recirculation systems and helps maintain consistent temperature delivery. (Section A-1.2)
- installation, operation, and service manuals: Guides provided by manufacturers with information on how to safely install, use, and maintain appliances, including safety warnings, wiring diagrams, and troubleshooting tips. (Section A-1.3)
- manufacturers specifications (datasheets): Instructions or details provided by the maker of a product, explaining how the product should be used, installed, and maintained. (Section A-1.3)
- moisture exhaust duct: The ductwork used in gas dryers to vent humid air and combustion by-products to the outdoors, as required by code. (Section A-1.2)
- MOSFET adaptor: (Metal-Oxide-Semiconductor Field-Effect Transistor); A small electronic part that helps turn gas appliances on or off safely. It controls how electricity flows to important safety parts like sensors or shut-off devices. (Section A-1.2)
- rating plate: A metal or plastic tag on an appliance that shows important details, like how much power it uses, how to install it safely, and any safety standards it meets. (Section A-1.3)
- thermocouple interrupter: A component used in some gas appliances to shut off the gas supply in case of sensor failure or unsafe operating conditions, often used with CO detectors. (Section A-1.2)
- thermal trap: (Also known as combustion air pot), a part of a heating system that helps improve efficiency and safety. It works by trapping heat that would otherwise escape, ensuring that the hot air stays where it’s needed. This trapped heat can then be used to warm up the air needed for combustion, making the system more efficient. The combustion air pot also prevents dangerous gases from leaking out by keeping them contained. (Section A-1.1)
- ventilation: The intentional introduction of outdoor air into a space to control indoor air quality by diluting and displacing indoor pollutants; can also be used for purposes of thermal comfort or dehumidification. (Section A-1.2)
- warranty: A guarantee from the manufacturer that a product will be free from defects for a certain period, with free repairs or replacements offered if needed. (Section A-1.3)
