Day & Night furnaces are fairly standard home furnaces with direct ignition, an insulated cabinet for reduced noise, induced draft motor and temperature limit control, an electronic control panel and a limited warranty on parts and the heat exchanger. Calling for service may not be necessary, however, if you resolve some basic problems that may occur with the Day & Night furnace through some troubleshooting efforts.

Step 1

Wait 30 minutes if the furnace has shut off unexpectedly due to a power failure and then adjust the thermostat to the lowest setting. Open the Day & Night furnace access door and turn the gas control knob to "Off" and wait five minutes to allow the gas to move through the lines. Stop and sniff for gas before continuing, and leave the house if you smell gas. Call your gas company. Turn the gas control knob to "On" if you don't smell gas and close the front panel. Return power to the furnace and adjust the thermostat to "Heat" and the desired temperature setting.

Step 2

Check the thermostat if the furnace has power and is lit but is not running. Set the thermostat to "Heat" and increase the temperature setting. Find the return and supply grilles in the home and move any furniture, rugs, toys or other objects away from the vents to allow for proper heat transmission.

Step 3

Shut off the furnace and clean the filter if the furnace is heating poorly or running more often than expected. Open the access panel and slide the filter out, then either replace the filter if the original filter was disposable or clean the filter if the original filter was permanent. Wash thoroughly and rinse well, then air dry. Do not replace the filter into the furnace until completely dry. Close the access door when the filter has been replaced and turn the furnace back on.

Step 4

Disconnect power to the furnace and allow the furnace to cool completely if the furnace is operating noisily. Open the access panel and clean out excess dirt and debris from the blower and burner area, avoiding the burner itself, using a soft brush. Shut the access panel and restore power.