Gas Appliance Safety Training Seminar

B. A. T.Basic Appliance Training Basic Gas Appliance Service presented by Jim Campbell, Mcap

Outline • Gas Basics • Safety • Characteristics • Fuel Gas Code Requirements • Gas Testing Devices • Gas Ranges • Gas Dryers • Gas Water Heaters

Gas Basics • This program is not designed to give you all the necessary skills and information to service all gas appliances but will form a foundation to help build your skills and knowledge. • Further information and experience will be necessary to completely understand all aspects of servicing gas products.

References • NFPA 54 – National Fuel Gas Code • NFPA 58 – Liquefied Petroleum Gas Code • NFPA 501 & 501A – Standards for Manufactured Homes • Various service guides & training programs from Gas Appliance manufacturers

Gas Basics - Safety • For your personal Safety: • Always use a combustible gas indicator to check for gas in the atmosphere as you enter the service area. Don’t trust your nose to warn you. • Ask the customer if they have been smelling gas. • Check high for Natural Gas, check low for LP Gas.

Gas Basics - Safety • Combustible gas indicators (CGI)

Gas Basics - Safety • Mops, brooms, newspapers or any flammable materials should not be stored near gas appliances. • Paints, solvents, gasoline or any combustible products should not be in the same room.

Gas Basics - Safety • Make sure a flexible gas line connection is installed connecting the gas houseline to the appliance to reduce the likelihood of damage if movement should occur. • All gas appliances should have a gas shut-off valve installed in the gas line that lets you turn off the gas to that appliance if there is a gas leak.

Gas Basics - Safety • Make yourself aware of where the main shut-off is or the gas meter / shut-off in case of any emergency while you are in the customer’s home. Main shut-off

Gas Basics – SafetySafe Servicing Practices • Be sure to wear Safety Glasses and any other Personal Protection Equipment while performing service work. • Before servicing or moving an appliance: • Disconnect power • Turn off the gas supply • Turn off the water supply • Be sure to exercise “Lock-Out / Tag-Out” procedures

Gas Basics - Safety • NEVER interfere with the proper operation of any safety device. It is never acceptable to bypass a Safety or an operating control and leave the unit in operation. • Use only replacement parts designed for that specific appliance. • NO MacGyver-ing

Gas Basics - Safety • Prior to returning an appliance to service: • Make sure all electrical connections are correct and secure, dressed, away from sharp edges and moving parts and well insulated and protected from damage. • See that access panels are securely reassembled and all screws back where they belong.

Gas Basics - Safety • One of the major concerns when working on Gas Burning appliances is the production of CO (Carbon Monoxide). • All Gas Burning appliances have the potential for creating CO.

Gas Basics - Safety • Gas Burning appliances produce excessive CO if: • Burners are not properly adjusted • Flame impingement is occurring • Improper venting • Lack of air for complete combustion

Gas Basics – SafetyEffects of CO Poisoning 9 ppm The maximum allowable concentration for short-term exposure in a living area according to ASHRAE. 35 ppm The maximum allowable concentration for continuous exposure in any eight-hour period, according to federal law. 200* ppm Slight headache, tiredness, dizziness, and nausea after two to three hours. 400 ppm Frontal headaches within one to two hours, life-threatening after three hours, also maximum parts per million in flue gas according to EPA and AGA. 800 ppm Dizziness, nausea, and convulsions within 45 minutes. Unconsciousness within two hours. Death within two to three hours. 1,600 ppm Headache, dizziness, and nausea within 20 minutes. Death within one hour. 3,200 ppm Headache, dizziness, and nausea within 5 to 10 minutes. Death within 30 minutes. 6,400 ppm Headache, dizziness, and nausea within 1 to 2 minutes. Death within 10 to 15 minutes. 12,800 ppm Death within 1 to 3 minutes. * Maximum CO concentration for exposure at any time as prescribed by OSHA. Effects can vary significantly based on age, sex, weight, and overall state of health.

Gas Basics - Safety • The CPSC (Consumer Product Safety Commission) recommends that an approved CO detector be installed in every home. • CO detectors should be mounted in and around the sleeping areas, not in a kitchen or near gas burning appliances.

Gas Basics - Characteristics

Gas Basics - Characteristics • Natural Gas ratio Gas to Air • 4% to 14% • Propane ration Gas to Air • 2% to 10%

Gas Appliance Testing Devices If you use Soap Solution when testing for leaks, you must clean it off to eliminate corrosion.

Gas Appliance Testing Devices - Manometers • Manometers are primarily used to measure pressures of less than 1 PSI. • If you use a spring gauge to check gas pressures, always check your spring gauge for accuracy by comparison to known pressures or a manometer. • Manometers normally indicate pressures in “Inches of Water Column” (“wc).

Gas Appliance Testing Devices - Manometers • How to read a manometer:

Gas Appliance Testing Devices - Manometers • This is a commonly used Direct Read manometer. Upright mode for common measurements. Incline mode for pressures less than 1”wc

Fuel Gas Codes • If you work on Gas burning appliances you should have the applicable code available to you • National Fuel Gas Code – NFPA54 • NFPA 501 & 501A – Standards for Manufactured Homes • NFPA 58 – LP Code • International Fuel Gas Code • Local Jurisdiction codes

Fuel Gas Codes • Fuel Gas Codes establish the bare minimum requirements for gas burning equipment: • Installation • Piping • Connections to fuel system • Combustion Air Requirements • Venting

Fuel Gas Codes • Appliances must have a shut-off valve within 6 feet of the appliance. • Connectors must be approved connectors • Primarily Stainless Steel or Coated connectors • Appliances must be supplied with the required gas supply, pressure & quantity

Fuel Gas Codes • The major concern when it comes to the gas burning appliances that we deal with; gas ranges, gas dryers and gas water heaters, is the amount of air available for proper combustion. • Unless we go through exhaustive measures to determine the amount of infiltration air into the structure where the appliance is installed, we fall back on the minimum requirements for equipment.

Fuel Gas Codes • The minimum amount of air required by Standard Method: • The minimum required volume shall be 50ft3 / 1000 Btu / hr • If we have a standard gas range with 4 surface burners and the two oven burners, bake and broil; it is rated for 65,000 Btus input, how much air is required? • _________________ft3

Gas Ranges • Gas ranges are different from Electric ranges because the heat comes from a gas flame instead of a heating element. • Natural Gas is delivered to the range at approx. 7”wc. A regulator inside the range drops the pressure to a normal manifold pressure of 3.5 to 4”wc. • Measuring the gas pressure would be done using a manometer or magnehelic gauge.

Gas Ranges • The surface burners are supplied with gas through the burner valve

Gas Ranges • Actual surface burner gas valve operation • Burner adjustment

A B C D Gas Ranges • Checking burners • Which flame indicates proper combustion?

Gas Ranges • Flame quenching – normally results in a complaint about odors. • Customers may complain about gas odors or even CO. They are actually smelling the Aldehydes from incomplete combustion. • Improper flame diagnostics • Cleaning burners

Gas Ranges • Gas burner ignition systems include: • Standing pilot • Spark (Electronic) ignition • Hot Surface ignition • Standing pilot, surface burners

Gas Ranges • Relighting standing pilot • Ensure pilot is not too high, causes soot under pilot hood and creates Aldahydes • Adjusting the pilot • Turn the pilot up just enough to keep it lit • Cleaning the pilot • Never, Never use a broach to clean a pilot. A broach is a three sided file and will enlarge the pilot and cause problems. Use compressed air.

Gas Ranges • Electronic ignition • Consists of the following components: • Ignitor switches • Ignitor spark module • Surface burner ignitors (electrodes) • Ignitor switches for the surface burners are wired in parallel to each other.

Gas Ranges • When the burner control is turned to “Lite”, the switch closes a 120 Volt circuit to an Electronic Spark Module. The module steps up the 120 Volt input to approximately 10,000 to 20,000 volts. The high voltage causes the current to jump from the electrode to ground.

Gas Ranges • Spark Module and Spark Electrode

Gas Ranges • Surface burner layout

Gas Ranges • Sealed burner layout

Gas Ranges • Types of Electronic ignition systems for surface burners: • All burners spark & oven sparks • One side of burners & oven independent • One burner sparks & oven is independent • Electronic ignition diagnostics • Burners spark for no reason, middle of night.

Gas Ranges • Oven ignition systems: • Standing pilot • Intermittent spark • Hot Surface (Glow bar)

Gas Ranges • Standing Pilot

Gas Ranges • Oven Safety Valve • Stand-by vs. Heater pilot

Gas Ranges • Oven Safety Valve opening

Gas Ranges • Hot Surface (Glo-Bar) Ignition, aka – HIS

Gas Ranges • HSI operation • 1 • 2 • 3

Gas Ranges • Testing components • Oven control • May have to Choke it • Burner switches • Test for open and close • Limits • Should all be normally closed • Locking mechanisms • Are the switches in the correct positions • Now what about this Choking thing?

Gas Ranges • Testing components, Glo-Bar ignitors Either ignitor should read about 50 to 150 ohms resistance when cold. 2.5 to 3.0 Amps 3.0 to 3.6 Amps

Gas Ranges • Testing oven temperature sensor

Gas Dryers • Everything about Gas Dryers is the same as Electric Dryers except for the source of heat and Gas Dryers operate on 120 Volts instead of 240. • Timers / PCB boards are about the same • Thermostats are the same • Pretty much the same except for the gas burner.

Gas Appliance Safety Training Seminar