Gas or Oil Furnace Won’t Ignite Fossil fuel furnaces ... Possible causes for short cycling include dirty air filters, thermostat issues, or overheating. Dirty air filters restrict the airflow ...

Generally, you can get rid of an oil smell produced by the furnace by simply replacing the filter. However, in some cases, replacing the filter won't have any impact, in which case, you should ...

Learn more. In our tests, we gauge how well an air filter removes dust, pollen, and smoke from the air, and see how freely air flows through the filter at any fan speed. We also calculate the ...