No Heat Do-It-Yourself Checklist
Thermostat Settings.
Check thermostat for proper setting.
Turn the temperature UP to the temperature you’d like your room. If your room
temperature is warmer than the temperature you're setting your thermostat, the
furnace won't run until the room temperature drops below your setting.
Set the thermostat “auto/on” switch to “auto” to cycle the furnace blower on and
off only when the furnace is supplying heat. Turning the “auto/on” switch to
“on” will keep the furnace blower on between cycles. The furnace blower in this
"on" setting will run all the time. This promotes a more even heat distribution
and improves the air circulation throughout the home.
Filters
Are your furnace filters clean? Dirty filters can reduce air flow through the furnace, and causing your blower to overwork, and possibly making the heat delivery inadequate to heat your house. And dirty filters are unsanitary. Change conventional cardboard-frame fiberglass filters once a month. Media filters should be changed once at the beginning of the heating season, and once at the beginning of the air conditioning season. Electronic air cleaner cells should be rinsed once a month.
Gas Valve
Gas valve should be turned “on”. If you don’t know which part the gas valve is, chances are you should have a professional check this one for you. We don't want to see our do-it-yourselfers on the 10 o'clock news.
Pilot Light
Your pilot light, if you don’t have an electric ignition system, should be lit. Electric ignitions systems include spark systems, glow-plug systems, and other specialized systems such as the Lennox Sure-Light ignition. You won't see a pilot flame if you have an electric ignition system. Once again, don’t check this if you don’t have experience at it. We can’t explain this one over the phone, for safety reasons.
Blower Safety Switch.
The door to the blower compartment of most furnaces operates a safety switch. Similar to the light switch operated by your refrigerator door, this switch is pushed in only when the door is properly in place. If the switch is not pushed completely in, as when the panel is not properly installed, the furnace (or air conditioner for that matter) will not operate.