I have a forced hot air TRANE heating unit. Recently, it hasn't been working correctly, if I put the thermostat on 64,65, etc... degrees it never gets to the temp...I can also hear a clicking sound when it comes on, about once every 5 seconds...overall the unit doesn't sound the same when it is running correctly, definitely not as much airflow as when it is working right. I checkecd the unit - as in there is a light that blinks - troubleshooting - and everything is fine. Anyways, it never comes to temperature so it comes the heat comes on every couple of minutes. Any advice from anyone? Also, the airducts are very noisy, any chance there could be problems there?