why is my rollout switch tripping open on my gas furnace?

Question

periodically, the rollout switch trips and i don't get heat until i reset the switch. then after awhile, it does the same thing again

Answer 1

yup, it might actually be rolling out. have you had it serviced this yr? maybe you should have it cleaned and have them throw in a switch while they re there. its much cheaper that way. for the 150 you ll have into the whole, isnt it worth the peace of mind?

Answer 2

rusty burners cause uneven flame
this causes the flame to pool up and roll out of the chamber.
The safety's are there to prevent that roll out from causing a major fire around the furnace. A bird nest,or wasp nest, or cob webs in the stack can cause the roll out to pop or it may just be the switch itself(highly unlikely) rusty burners need to be removed and wire brushed to open any holes that may be blocking the gas that produces the flame evenly.
A roll out switch or a POOF switch reacts to excessive heat in the burner chamber. Imagine a burner with a split in it causing massive gas to pour out of it instead of an even gas flow. Imagine only half of the burner going while the other half is raw gas spewing out until finally enough gas comes out to ignite in the chamber and POOF. yeah you remember the heater doing that but it was OK then. Well it will only get worse.try cleaning the burners.Make sure all the rollouts are reset.In the photo below, the middle thing is a roll out.The other 2 are High limits that reset themselves.And are in older models.

Answer 3

In photograph 5.JPG is there a reset button on the other end of that switch? If so, turn the power off and push the button. Restore power and turn your furnace on. The limit switch is designed to prevent the burner from igniting when not enough airflow is going through the heat exchanger which would cause it to overheat. As you already figured out this could be caused by dirty filter or too many closed registers. I have in the past called a local HVAC company and they helped me over the phone so I could do it myself. You might not be as fortunate but it's worth a shot.

Answer 4

maybee it's actually rolling out, or just replace it = fairly cheap and easy.