Problem: Why does my furnace rollout switch have to be reset so often? Why do rollouts have different temperature differences?
Answer: The rollouts switchs and limit are determined by the engineers during the furnace building and testing process. Different areas of the furnace are allowed different heat measurements before they are determined to be safe or unsafe. If the furnace limit or rollout switch senses that over-heating occurs then it trips the rollout switch to prevent an unsafe over-heating condition. Many times when a limit or rollout trips or opens up it will tell the furnace control board that the furnace has over-heated and the blower on the furnace will run continuous to cool the furnace down until the power on the furnace is turned off and back on again. If your limit goes off again I would strongly suggest you get your furnace checked out to make sure something is not stopped up, and to make sure you do not have a leak in the heat exchanger. This can be very dangerous! We sell limits and rollout switches on the following page: Please click here if you would like to see the furnace limits and rollout switches we sell. Below we have a real good Youtube video which shows what happens when a heat exchanger or vent gets stopped up and gas flames rollout of the front of the heat exchanger. The rollout switches are placed as a safety device around the burner area to sense the hot flame or hot exhaust thus shutting down the furnace so you do not get a fire or get carbon monoxide poisioning. The video below shows an exaggerated version of what furnace flame rollout looks like. If you feel any heat coming out of the front of the furnace or if your rollout switches are going off then I would suggest calling a service company to make sure your furnace is safe. If a furnace has a leaking heat exchanger you can feel more heat come out of the furnace when the blower on the furnace starts up because a crack in the heat exchanger will allow blower air to enter the heat exchanger which creates a dangerous condition. Below we have a picture of two limits and one rollout switch. The push button manual set rollout switch is located in the middle. We also have another real good informative video made by RepairClinic.com which shows how to replace a rollout switch. Thanks to RepairClinic.com for making this informative video! If your rollout switch is having to be reset please call a service company to check your furnace out. If you have any other questions please feel free to email us: firstname.lastname@example.org or comment in our comments section below. We would love to have your business!