Make believe you live in a cold climate. Tonight your spouse shakes you awake at 5 a.m. on a late January morning. The house is cold and it is snowing outside. You usually turn the thermostat back a bit at night, but the temperature in the house is 52 degrees Fahrenheit (you determine this fact by looking at your desk thermometer). Something is obviously wrong. Your spouse says the house is too cold for your 18-month-old daughter and asks you to do something to get the heat back on. As a temporary measure, your spouse brings your daughter into your bed to keep her warm (temporarily solving one "real" problem). You start to solve the problem by mentally filling out the troubleshooting worksheet. Troubleshooting Worksheet Continue your trouble shooting-analysis by filling out a K.T. problem analysis table and a "Does It Fit the Observation?" table. What When Where Extent Cause Thermostat battery is dead Furnace filter is blocked or partially blocked Electricity to furnace is out Natural gas supply to heat the house is shut off Is House cold Sometime since bedtime last night. Entire house Only furnace Result Is Not Normal or too high in temperature Prior to bedtime. Localized to one room. Water heater or other utilities Does it Fit the Observation? Yes Yes Yes Yes Based on your findings what did the problem turn out to be? Distinction Steps Needed to Check Cause Remove or replace battery Remove filter and temporarily run without one Reset circuit breaker Possible Cause Furnace is off Varies - may need to open furnace up Low Outside temperatures. Thermostat problems, natural Does It Fit The Observation? Feasibility gas outage, plugged furnace filter. Thermostat problems, plugged furnace filter, other more complicated electrical problems. Easy, if a spare battery is handy Easy Easy Need a trained technician