Gas and Oil Home Heating Furnaces - short cycle on furnace

I have a forced hot air gas fired furnace that is three years old. I was working in the area of the furnace and I noticed that the burner comes on for 30 seconds then off again for 30 seconds. This cycle continues until the thermostat is satisfied. The blower remains on throughout these cycles and then shuts off when the furnace has cooled down, which is normal. The old furnace burner stayed on as long as there was a call for heat. Is this just a new way of cycling through the heating cycle ? The filter is clean and the ducts are open. Thank you !

The burner should stay on the whole time during call of heat.

Check your venting..

Is it 90%?

What kind of filter are you using? Take your filter out and see if it stays on. if it does, then the filter is not letting get enough air flow, and cycling on high limit.


Brand of system? Type of igition?

next possible problem is bad HSI (hot surface ignitor), or dirty flame sensor.

It turned out to be a bad pressure switch. Thanks for your help!