Front furnace limit cycling
Just got back from a trip this morning during which we camped in 40 deg nights. Started the front furnace in my 390RB and noticed it lights and runs for about 90 sec and then apparently hits a limit, shuts down the burner but the fan continues to run. The burner stays off for about 3 minutes, relights and repeats the cycle. As a result it never reaches the requested temperature and just continues to run in this manner. This furnace has some rather small ducts under the loveseat so I'm wondering if the ducting is restricting flow or if I have a bad limit switch?
Anyone else have this happening?
2013 Berkshire 390RB-60
toad - 2002 Jeep Wrangler Sport