What is a variable output programmable thermostat? It is a thermostat that can send a varying or proportional signal to the furnace controller of a modulating gas furnace.Likewise, what are the 4 types of gas furnace airflow patterns?
90 Cards in this Set
| The four types of gas furnace air flow patterns are_________, ________, _________ and___________ | up flow, down flow, low boy and horizontal |
| Natural gas, A. Is lighter than air B. Has approximately the same specific gravity as air C. Is heavier than air | A. Is lighter than air. |
Furthermore, what is a hot surface ignition system? The Hot Surface Ignition system includes a combination gas valve, a Hot Surface Igniter, and control module. The heat produced by the igniter lights the main gas flow through the burner. Hot Surface Ignition makes use of a silicon carbide igniter that is heated to a red-hot condition.
Secondly, why is excess air supplied to all gas burning appliance burners?
Excessive air is supplied to all gas burning appliances to support combustion. The purpose of a gas regulator at a gas burning appliance is to? The purpose of a gas regulator at a gas burning appliance is to drop the pressure to the proper level (in.
What is soft lockout?
When this occurs, often after two or three failed restart attempts, the furnace is known to be in lockout mode and will not attempt to run again until the furnace is manually reset. It is important to note that there are soft and hard lockouts, which does vary by manufacturer.
What is the most common manifold pressure for natural gas furnaces?
The most common manifold pressure for natural gas furnaces is? 3.5 inches wc.What is a smart valve?
The Smart Valve system uses a 24 VAC powered hot surface pilot gas igniter to ignite the pilot gas. The main gas is ignited in both instances by a pilot gas burner. The Smart Valve system is self-contained, thus eliminating the need for a separately mounted ignition source, usually in the furnace or boiler vestibule.What would cause too much temperature difference?
Airflow Determinations Too low of an airflow will give you greater temperature differences across the coil than too much airflow. This greater temperature difference is caused from the air being in contact with the coil longer, thus decreasing its temperature coming out of the coil.What is the typical line voltage for gas furnaces?
24 volts
What is a glow coil?
Glow coil. A device that automatically reignites a pilot light if it goes out. Hard lockout. Is a time period built into the module that allows for a certain time to light or relight the pilot or main burner.What is a direct vented furnace?
Direct-vent (two-pipe) system: The two-pipe system is most common in home heating applications. It provides a direct intake vent that brings outside air to the sealed combustion chamber with one pipe, while a second vent pipe provides sealed venting of exhaust gases back to the outside of your house.How many volts are generated in the spark ignition circuit?
The voltage that is available to the spark plug is somewhere between 20,000 volts and 50,000 volts or better. The job of the ignition system is to produce that high voltage from a 12 volt source and get it to each cylinder in a specific order, at exactly the right time.What is the purpose of dilution air?
Dilution air is the air that combines with the flue gases and lowers the oncentration of the emissions. There are two types of dilution air, natural and induced (artificially created). Time, Temperature and Turbulence. The combustion process is extremely dependent on time, temperature, and turbulence.What are the 3 products of complete combustion?
Products of Complete and Incomplete Combustion Combustion is a chemical reaction that changes a fuel source, such as propane, into a useful form of energy, such as heat. Combustion requires all three ingredients: fuel, oxygen, and an ignition source.What controls the amount of gas entering the burner?
Adjusting the gas valve on the Bunsen burner changes the volume of gas flow; the more gas entering the burner, the larger the flame. The collar at the base of the barrel contains air holes to control the amount of oxygen reacting with the gas.Which condition will cause the flame to lift off a gas burner surface?
In short, too high a pressure at the burner face can cause flame lift-off. There is also a problem with a very low gas velocity or a very low flow.How does flame rectification work?
In a nutshell, the flame rectification system is an electrical process that causes a low level DC current to be conducted from the flame rod through the flame, and back to ground. If the flame current is too low, or not present, the ignition controller will stop the ignition operation and stop the flow of gas.What is the function of a flame rollout safety switch?
The rollout switches are placed as a safety device around the burner area to sense the hot flame or hot exhaust thus shutting down the furnace so you do not get a fire or get carbon monoxide poisioning.What is the difference between a yellow gas flame and an orange gas flame?
What is the difference between a yellow gas flame and an orange gas flame? Yellow flame represents starved air flame. Carbon monoxide produced. Orange flame represents burning of dust.What gases are contained in the products of complete combustion?
During complete combustion carbon and hydrogen combine with oxygen (O2) to produce carbon dioxide (CO2) and water (H2O). During incomplete combustion part of the carbon is not completely oxidized producing soot or carbon monoxide (CO).What is the purpose of the draft diverter?
Draft diverters, or draft hoods, gather the exhaust gases from the flue(s) of a water heater in order to be safely vented to the exterior.What is the minimum size flue pipe that should be attached to a gas furnace?
The Right Size Flue Pipe The pipe you purchase should match the inside diameter of the hole. It can be larger but must never be smaller or leaks will result. The average stove and furnace today requires a 3 inch diameter pipe, but can go as large as 8 inches. A pellet stove needs only a 4 inch pipe. 
