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The heating and cooling systems of your home play a key role in the comfort of you and your family, controlling the indoor climate against the fall and rise of the temperature outdoors. Well-maintained heating and cooling systems can offer safe, reliable, uninterrupted service-with little risk of failure at the peak of your need for them. Although heating and cooling systems can be of many different types, with different parts assembled in different ways, each one is comprised of four basic components: a heat or cool-air producer, a heat exchanger, a distribution system and a thermostat. With a heating system, the heat producer can be a gas burner, an electrical heating element, an oil burner or a heat pump. The heat exchanger can be a furnace or a water boiler. Heat can be circulated throughout the house by a water distribution system, a network of concealed pipes and radiators or convectors, or by an air distribution system, a network of concealed ducts and registers. The thermostat monitors the temperature indoors and regulates it, turning on and off the heating system. With a cooling system, the cool-air producer can be a central air conditioning unit, a window air conditioner or a heat pump-because of the flow of refrigerant used to transfer heat, a heat pump can be used for cooling as well as heating. Evaporator coils serve as the heat exchanger and cool air usually is circulated throughout the house by an air distribution system. The thermostat operates the same way and provides the same function as with a heating system. The Troubleshooting Guide lists quick-action steps to take in the event of an emergency for more detailed instructions. In some instances, you may need to shut off power to the heating or cooling system, shutting off the unit disconnect switch and the circuit --and then shut off the gas supply to the gas burner, the oil supply to the oil burner or the water supply to the water boiler. In other instances, you may be able to try a stopgap measure: relighting the pilot of a gas burner; replacing a fuse of an electrical heating element; resetting an oil burner or cleaning its photocell; checking the defrost system of a heat pump; jumpering a low-voltage thermostat. The list of Safety Tips at right covers basic guidelines to help you prevent a heating or cooling system emergency in your home. If you are ever in doubt about your ability to handle an emergency, don’t hesitate to call for help. Post the telephone numbers for the fire department and each of your heating and cooling system utilities, including the gas or oil company, near the telephone; even in non-emergency situations, qualified professionals can answer questions about the safety of your heating or cooling systems. In most regions, dial 911 in the event of a life-threatening emergency. === SAFETY TIPS 1. Locate and label or tag the main shutoff for each utility in your home: electricity; gas; propane; water; oil; in the event of an emergency, you will want anyone to be able to find them quickly. 2. Natural gas and propane gas are treated with a sulphur- based chemical to give them a strong odor of rotten eggs. If your heating system has a gas burner, make sure you and your family members are familiar with the distinctive odor of gas; as an added precaution, install a gas detector near the gas burner. 3. If you return home and detect the odor of gas, don’t enter the house; call the gas company or the fire department immediately from the home of a neighbor. 4. If you detect the odor of gas, don’t use any electrical switch or outlet, light a match or use the telephone-a spark could cause an explosion or a fire. Leave the house immediately, then call the gas company or the fire department from the home of a neighbor. 5. Call your heating and cooling system utilities, including the electricity utility and the gas or oil company, before excavating on your property or building an addition to your home. 6. Ask the gas or oil company for an annual checkup of your heating system, including a measurement of the carbon monoxide level in your home; as an added precaution, install a carbon monoxide detector. 7. Collect any leaking oil or water in a bucket or basin and clean up any oil spill immediately. Dispose of any oil-soaked waste material following the recommendations of your local fire department or environmental protection agency. 8. Keep furniture and curtains away from electrical baseboard heaters and make sure the registers of an air distribution system are unobstructed. Use an electrician's fish tape or a long stiff wire to pull any blockage out of a duct. 9. Store paints, solvents and other flammable materials away from gas or oil burners and electrical heating elements. Never apply contact cement, paint stripper or any other flammable substance near a gas or oil burner; a buildup of fumes can trigger an explosion. 10. Ensure your heating and cooling systems are installed ac cording to local building codes and serviced according to the manufacturer's instructions. Inform your insurance agent of any major changes made to your heating or cooling system. 11. When undertaking a repair, use only replacement parts and wiring of the same specifications as the original. Look for the UL (Underwriters Laboratories) or CSA (Canadian Standards Association) label on new parts. 12. Keep at least one fire extinguisher rated ABC in your home and know how to use it in the event of a fire. 13. Never work with electricity in damp or wet conditions. Know how to work safely at the service panel. 14. Don’t attempt to temporarily bypass the high-voltage thermostat of an electrical baseboard heater. Before servicing any low-voltage thermostat, shut off power to the heating or cooling system, shutting off the unit disconnect switch and the circuit. === 109--- Fuse pullers--Used to remove cartridge fuses; must be made of plastic or other nonconductive material. Photocell--Detects the presence of ignition flame inside an oil burner, permitting system to operate. Low-voltage fuse--Can be used to protect circuits of electrical furnace; available in ratings up to 20 amperes. Time-delay fuse--Can be used to protect unit disconnect switch; fuse withstands momentary power surge when system starts up, but blows if circuit overloaded or shorted. Jumpering cable--Insulated electrical wire that routes electricity from one terminal to another; can be used to temporarily bypass faulty low- voltage thermostat. Batteries --Used to power internal circuits of electronic thermostat. Cartridge fuse--Can be used to protect circuit of electrical heating element or indoor unit disconnect switch; available in ratings up to 60 amperes. Air filter--Filters air delivered to furnace from return duct. === TROUBLESHOOTING GUIDE SYMPTOM [ Heating system does not work; Cooling system does not work; Heating system runs but does not heat; Cooling system runs but does not cool Heating system does not shut oft Cooling system does not shut off Sparks or burning odor from heating or cooling system Shock from heating or cooling system Strong gas odor Faint gas odor; localized near furnace Gas pilot does not light and stay lit Oil burner or oil supply pipe leaks Heat pump, central air conditioning unit or window air conditioner leaks refrigerant (oily fluid) Water boiler or water supply pipe leaks; Radiator, convector or water distribution pipe leaks Auxiliary light of heat pump indoor thermostat glows continuously] PROCEDURE [ Raise thermostat setting; Restore power to heating system, turning on circuit and unit disconnect switch (111) Service heat pump (114) If oil or propane level of tank low, call for delivery Relight gas pilot (94); service electrical heating element (112); service oil burner (113) Service water distribution system (114); service air distribution system (115) Service low-voltage thermostat (116) Have heating system inspected and repaired as soon as possible Lower thermostat setting Restore power to cooling system, turning on circuit (83) and unit disconnect switch (111) Service electrical heating element (112) Service air distribution system (115); service window air conditioner (115) Service low-voltage thermostat (116) Have cooling system inspected and repaired as soon as possible Service heat pump (114) If oil or propane level of tank low, call for delivery Service water distribution system (114); service air distribution system (115) Have heating system inspected and repaired as soon as possible; Service air distribution system (115); service window air conditioner (115) Have cooling system inspected and repaired as soon as possible Lower thermostat setting Shut off power to heating system, shutting off unit disconnect switch (111) and circuit (83) Have heating system inspected and repaired as soon as possible Raise thermostat setting Shut off power to cooling system, shutting off unit disconnect switch (111) and circuit (83) Have cooling system inspected and repaired as soon as possible Don’t touch any heating or cooling system unit. Immediately shut off power to heating or cooling system, shutting off unit disconnect switch (111) and circuit (83); or, shut off electrical system (82) If flames or smoke come from heating or cooling system unit, leave house immediately and call fire department from home of neighbor Have heating or cooling system inspected and repaired as soon as possible Don’t touch any heating or cooling system unit Immediately shut off power to heating or cooling system, shutting off unit disconnect switch (111) and circuit (83); or, shut oft electrical system (82) Have heating or cooling system and electrical system inspected and repaired as soon as possible Don’t use any switch, outlet or telephone or light any flame Leave house immediately and call gas company or fire department from home of neighbor Don’t use any switch, outlet or telephone or light any flame Shut off gas supply to gas burner (92) Ventilate room (93) If gas odor persists, shut off main gas supply (92); propane (93) If propane level of tank low, call for delivery When gas odor dissipates, restore gas supply and relight pilots (94) If gas odor persists, leave house and call gas company or fire department from home of neighbor Have heating system inspected and repaired as soon as possible Shut off gas supply to gas burner (92) If gas odor detected, ventilate room (93) and shut off main gas supply (92); propane (93) If propane level of tank low, shut off main gas supply (93) and call for delivery If gas odor persists, leave house and call gas company or fire department from home of neighbor Have heating system inspected and repaired as soon as possible Cope with oil emergency (111) Have heating system inspected and repaired as soon as possible Don’t touch refrigerant or any exposed refrigerant pipe Shut off power to cooling system, shutting oft unit disconnect switch (111) and circuit (83); off and unplug window air conditioner Have cooling system inspected and repaired as soon as possible Cope with water emergency (112) Have heating system inspected and repaired as soon as possible Cope with water emergency (112). Have heating system inspected and repaired as soon as possible Service heat pump (114). If problem persists, have heat pump inspected and repaired as soon as possible. ] 111ab--- SHUTTING OFF ELECTRICITY TO THE HEATING OR COOLING SYSTEM Shutting off power at the unit disconnect switch. Locate the unit disconnect switch: for a furnace or a water boiler, usually indoors near it; for a heat pump or a central air conditioning unit, usually outdoors near it. If the area around the unit disconnect switch is damp, wear rubber gloves and stand on a dry board or wear dry rubber boots. At an indoor unit disconnect switch, set the switch to OFF , shut ting off electricity; if the unit disconnect switch is controlled by a lever, set it to OFF (above, center). At an outdoor unit disconnect switch, raise the weatherproof cover and set the switch to OFF . As an added precaution, shut off power to the circuit (83). Open the cover of the unit disconnect switch to check any fuse protecting it; if necessary, remove each fuse as you would at a service panel (84) and use a continuity tester to test it (86). If a fuse is faulty, replace it with an identical fuse of the same amperage. Close the cover of the unit disconnect switch and restore electricity, turning on power to the circuit (83) and setting the unit disconnect switch to ON; at an outdoor unit disconnect switch, also lower the weatherproof cover back into place. 111cd--- COPING WITH AN OIL EMERGENCY Shutting off the oil supply to the oil burner. Shut off power to the furnace, shutting oft the unit disconnect switch (step above) and the circuit (83). Locate the valve on the oil supply pipe between the oil burner and the oil tank, usually found near the oil burner or the oil tank. Turn the handle fully clockwise , shutting off the oil supply to the oil burner. To restore the oil supply, slowly turn the handle of the valve fully counterclockwise. Turn on power to the furnace, turning on the circuit (83) and the unit disconnect switch (step above). Tag the valve for easy identification in the event of a future emergency. Cleaning up an oil spill. Caution: Don’t light any flame or smoke. Shut off the oil supply to the oil burner (step left). To temporarily plug a pinhole leak, wipe off the damaged section of pipe with a cloth, then wrap electrical tape tightly around it, overlapping the tape by about 1/2 of its width each turn and extending it 3 to 4 inches on each side of the leak. Wipe up any small oil spill with a cloth. Soak up any large oil spill by pouring an absorbent material such as cat litter or vermiculite on it ; when the oil spill is soaked up, scoop up the absorbent material with a shovel or a broom and dust pan. Dispose of oil-soaked cloths and absorbent material following the recommendations of your local fire department or environmental protection agency. 112ab--- COPING WITH A WATER EMERGENCY Shutting off the water supply to a water boiler. Locate the shutoff valve on the supply pipe to the water boiler, usually found near and above it. Turn the handle fully clockwise , shutting oft the water supply to the water boiler (and the hot water supply of the heating sys tem). If the valve leaks or there is no valve, turn oft the main water sup ply (99). To restore the water supply, slowly turn the valve fully counterclockwise or turn on the main water supply. Tag each valve for easy identification in the event of a future emergency. Shutting off the water supply to a radiator or convector. Locate the shutoff valve on the supply pipe to the radiator, usually found near it at floor level; with a convector, remove or reach under the front panel. Turn the handle fully clockwise , shutting off the water supply. If the valve leaks or there is no valve, turn off the water supply to the water boiler (step left). To restore the water supply, slowly turn the valve fully counterclockwise or turn on the water supply to the water boiler; put back any convector front panel you removed. 112cd--- SERVICING AN ELECTRICAL HEATING ELEMENT Testing and replacing the fuses. Shut off power to the furnace, shut ting off the unit disconnect switch and the circuit. To remove the front panel of the furnace, grasp its slotted handles, then tug it sharply upward and pull it off . Locate the control box cover, a hinged metal plate near the top of the furnace; unscrew it (above, center) and flip it down, then locate the fuses in a fuse block near the transformer or connected to a panel in the control box. Gently pry out each fuse with a fuse puller . Use a continuity tester to test each fuse (86); the bulb should glow if the fuse is good. If a fuse is faulty, replace it with an identical fuse of the same amperage. Gently push each fuse into place by hand. Flip up the control box cover, put back its screws and reinstall the front panel of the furnace. Turn on power to the furnace, turning on the circuit and the unit disconnect switch. If the problem persists, turn off power to the furnace and have it repaired as soon as possible. 113a--- SERVICING AN OIL BURNER 1 Resetting the oil burner. To check if the heat sensor is tripped and reset the oil burner, depress the reset button on the relay box and hold it for about 3 seconds. On most models, the relay box is mounted on the front of the furnace ; on some older models, the relay box may be mounted on the stack at the back of the furnace (inset). If the oil burner does not start, wait 1 minute, then depress the reset button once again. Caution: Never depress the reset button more than twice; unburned oil pumped into the combustion chamber of the furnace can accumulate and may explode or overheat when ignited. If the oil burner still does not start, open the ignition transformer (step 2) to check the photocell. 113bc--- 2. Opening the ignition transformer. Shut off power to the furnace, shutting off the unit disconnect switch and the circuit. As a safety mechanism, a photocell inside the ignition transformer shuts off the oil burner if its flame goes out; a dirty or faulty photocell, however, can shut off the oil burner when its flame is lit. To check the photocell, locate the ignition transformer-a hinged box usually on the top of the oil burner. Remove the screw holding the ignition transformer to the oil burner , then open the ignition transformer and locate the photocell. 3. Cleaning the photocell. Push the photocell and twist it counter clockwise to remove it from a bayonet socket ; pull out a plug-in photocell. Wipe any soot off the eye of the photocell using a clean cloth moistened with water (inset). Reinstall the photocell, reversing the procedure used to remove it, then close the ignition transformer and put back its screw. Turn on power to the furnace, turning on the circuit (83) and the unit disconnect switch (111). If the problem persists, turn off power to the furnace and replace the photocell with an exact duplicate. If the problem still persists, turn off power to the furnace and have the oil burner repaired as soon as possible. 114a--- SERVICING A HEAT PUMP Checking the defrost system. The auxiliary light of the indoor thermostat glows if the heat pump is in defrost mode or if a low temperature outdoors activates the auxiliary heating system. If the auxiliary light glows continuously and there is ice buildup on the outdoor coils, set the indoor thermostat to COOL , sending warm refrigerant from the indoor coils to the outdoor coils to melt the ice. Wait at least 30 minutes for the ice to melt. If the ice melts, the reversing valve inside the heat pump may have been stuck temporarily; reset the indoor thermostat to HEAT. If the ice does not melt or the problem recurs, turn off power to the heat pump (111) and have it repaired as soon as possible. 114bc--- SERVICING A WATER DISTRIBUTION SYSTEM Bleeding radiators and convectors. Air trapped in radiators and convectors can obstruct the delivery of heat. To bleed the air out of a water distribution system, work through the house from room to room, starting on the top floor. Use a cloth or a small container to catch escaping water. At a radiator with a bleed-valve knob, turn the knob counterclockwise 1 full revolution, bleeding the trapped air . At a radiator with a bleed-valve screw, turn the screw counterclockwise 1 full revolution using a screwdriver . At a radiator with an automatic bleed valve, unscrew the cap, then turn it upside down and push it into the valve-as you would to let air out of a tire. At a convector, unscrew and lift off the front panel to reach the bleed valve, then use the same procedure. Keep the valve open, bleeding the trapped air, until a steady stream of water flows from it-indicating all the trapped air is purged. Then, close the bleed valve, reversing the procedure used to open it. 115--- SERVICING AN AIR DISTRIBUTION SYSTEM Cleaning a disposable air filter. Shut off power to the furnace, shutting off the unit disconnect switch and the circuit. Locate the air filter in its slot on the side, front or top of the furnace and pull it out. To inspect the air filter for dirt, hold it up to a light or shine a flashlight at it. If no light or only a little light can be seen through the air filter, it’s clogged with dirt and should be replaced with an exact duplicate. If there is no replacement air filter on hand, clean it as a stopgap measure. Using a vacuum cleaner fitted with a soft-bristled brush attachment, gently remove dirt embedded in the fibers of the air filter . Slide the air filter into its slot, then turn on power to the furnace, turning on the circuit and the unit disconnect switch. SERVICING A WINDOW AIR CONDITIONER 1. Removing the front panel. Turn off the air conditioner and unplug it from the outlet. To reach the air filter, leave the air conditioner in place and take off the front panel. Remove the bolts or screws holding the front panel and lift it off the air conditioner. If there are no bolts or screws holding the front panel, grip each side of it and pull it off the air conditioner, releasing it from the retaining clips. 2. Removing the air filter. Locate the air filter in front of the evaporator coils or the blower fan. Release any retaining clips holding the air filter, then pull it off the air conditioner . If the air filter is dirty, clean it (step 3). If the air filter is damaged, replace it with an exact duplicate, reversing the procedure used to remove it; put back the front panel, then plug in and turn on the air conditioner. 116--- 3. Cleaning the air filter. Using a vacuum cleaner fitted with a soft-bristled brush attachment, gently remove loose dirt from the fibers of the air filter. Soak the air filter in a solution of mild household detergent and water to wash embedded dirt out of the fibers, then rinse it thoroughly with clean water and wring it dry. Rein stall the air filter, reversing the procedure used to remove it. Clean the air filter of the air conditioner the same way at the beginning of the season and at least once each month it’s in operation. 4. Cleaning the front panel. Clean off each side of the front panel. Using a cloth moistened with water or a stiff-bristled brush to remove dust and dirt from the grille ; dislodge stubborn particles with a toothpick or an old toothbrush. To remove greasy dirt off the front panel, soak it in a solution of mild household detergent and water, then rinse it thoroughly with clean water and dry it with a clean cloth. Put back the front panel, reversing the procedure used to remove it; then, plug in and turn on the air conditioner. SERVICING A LOW-VOLTAGE THERMOSTAT Jumpering a low-voltage thermostat (electronic model). Shut off power to the system, shutting off the unit disconnect switch and the circuit. If the low-battery light of the thermostat is glowing, pull the cover oft the base (inset) and replace each battery with an exact duplicate ; then, reinstall the cover and turn on power to the system, turning on the circuit and the unit disconnect switch. Otherwise, pull the cover off the base and use a jumpering cable to temporarily bypass the thermostat. Caution: Don’t attempt to jumper the thermostat of an electrical baseboard heater. Set the thermostat to AUTO and HEAT. Locate the terminals of the red and white wires on the base-marked R and W. Connect one clip of the jumpering cable to each terminal , then turn on power to the system. Don’t leave the house unattended; when the indoor temperature reaches a comfortable level, shut oft power to the system. 117--- Jumpering a low-voltage thermostat (round model). Shut off power to the system, shutting off the unit disconnect switch and the circuit. Pull the cover of the thermostat off the base and use a soft-bristled brush to clean off dust and dirt, adjusting the dial to help dislodge particles. Put back the cover, then turn on power to the system, turning on the circuit and the unit disconnect switch. If the problem persists, shut oft power to the system, pull off the cover and use a jumpering cable to temporarily bypass the thermostat. Caution: Don’t attempt to jumper the thermostat of an electrical baseboard heater. Unscrew the dial and lift it off the base. Set the thermostat to AUTO and HEAT. Locate the terminals of the red and white wires on the base-marked R and W. Connect one clip of the jumpering cable to each terminal , then turn on power to the system. Don’t leave the house unattended; when the indoor temperature reaches a comfortable level, shut off power to the system. Jumpering a low-voltage thermostat (rectangular model). Shut off power to the system, shutting off the unit disconnect switch the circuit. Pull the cover of the thermostat off the base and use a soft-bristled brush to clean off dust and dirt, ad ting the dial to help dislodge particles. Put back the cover, then turn power to the system, turning on the circuit and the unit connect switch. If the problem persists, shut off power to system, pull off the cover and use a jumpering cable to temporarily bypass the thermostat. Caution: Don’t attempt to jumper the thermo stat of an electrical baseboard heater. Unscrew the base (above, center) and gently lift it away from the wall, exposing the wires connected be hind it. Set the thermostat to AUTO and HEAT. Locate the terminals of the red and white wires-marked R and W. Connect one clip of the jumpering cable to each terminal , then turn on power to the system. Don’t leave the house unattended; when the indoor temperature reaches a comfortable level, shut off power to the system. Previous: Plumbing |