On my Lennox 80MGF gas furnace, the flame rollout switch opens within couple of minutes and never resets until I manually reset it. So when it is open the fan stays on (as it supposed to be) and soon the air becomes cold as the flame is off. I replaced the rollout switch but the new one also seems to be doing the same thing. If I bypass this rollout switch and operate with just one on the right, furnace seems to be functioning normally. Can someone help me identify the problem, please?
Pratab If you are a homeowner the problem you describe may be caused a couple of things. One of them heat exchanger leaks. The manual reset on this limit is to help identify that this type problem exists. Recommend that you contact your local Lennox dealer and have the furnace inspected and tested for the cause.
Heat exchanger leak allows air to be blown back into the heat exchanger causing the flame roll out switch to trip. Burner gas pressure too high. Restrictions in the vent system. These are things that a service tech can check for.
When you mentioned Burner Gas Pressure, I recall that couple of years ago, I had a similar situation and the technician who cam over to fix it said that the Pressure switch is gone bad and he replaced it. Now that I am seeing this problem again, I an not sure if that technician fixed the problem then.
Also I should mention one more thing that came to my mind. This problem happens only on very cold days/nights.
I just want to make sure this problem gets fixed properly this time. So can you refer some technician in Kennesaw, GA?