Component
Rollout switch
The rollout switch is a manual-reset safety in the burner area that trips when flame rolls out of the burner chamber instead of burning inside it. A tripped rollout switch means a combustion problem that must be found before the furnace is reset.
Smell gas?
- Do not operate light switches, appliances or phones inside.
- Leave the building and leave the door open behind you.
- From outside, call the FortisBC emergency line at 1-800-663-9911 or 911.
- Only after that, call BC Wide about the furnace.
A furnace that will not run is a breakdown, not a gas emergency. Gas smell, a CO alarm, soot or scorching are.
Short answer
If a rollout switch has tripped, the furnace will not run until it is manually reset, and it must not be reset until the cause is found: rollout happens when combustion air is inadequate, gas pressure is wrong, the burner is misaligned, or the heat exchanger is blocked. Carrier's manuals are explicit that the switch must never be jumpered and that the cause is corrected before resetting.
What rollout means
Flame rollout is the burner flame escaping the burner chamber instead of being drawn into the heat exchanger. It is usually brief and dangerous to the furnace and surrounding materials; the rollout switch detects the heat and locks the furnace out until manually reset.
Causes
The documented causes are the combustion basics: inadequate combustion air, improper gas pressure or burner set-up, blocked or restricted heat exchanger passages, a cracked exchanger, or a burner misaligned during service. Condensate or water in the burner area can also behave like rollout.
The reset rule
Manual-reset switches exist so that a human checks the cause instead of the furnace cycling through a combustion fault. The technician finds and corrects the cause, then resets the switch and verifies a full clean cycle. A homeowner should never jumper or repeatedly reset a rollout switch.
Related
Questions people ask
My furnace has a button to push on the switch. Can I reset it?
The manual reset exists for after the cause is fixed. Resetting without finding the cause lets a combustion fault repeat; if rollout recurs, stop and call. If you smell gas at any point, leave and call FortisBC at 1-800-663-9911 or 911.
Does a tripped rollout switch mean the heat exchanger is cracked?
Not necessarily; it means flame left the burner chamber. A blocked or cracked heat exchanger is one possible cause, and the inspection is part of finding the real one.
Is flame rollout dangerous?
Yes. It exposes flame where it should not be and can damage the furnace and surrounding structure. That is why the switch stops the furnace and why the cause must be found.
Need this looked at?
Call BC Wide with the brand, model number and anything on the display. Or
Request service online with this page attached.