Furnace Fault Codes

Furnace rollout switch codes: why it tripped

A rollout switch is the one fault code on a furnace that should never be reset and rerun without finding the cause. Here is what it means on each brand.

Every fault listed here is a gas-safety fault. They involve the gas valve, the burner compartment, or the heat exchanger — the parts whose failure can put combustion products, including carbon monoxide, into the air the house breathes. Do not keep resetting a furnace that reports one of these in order to hold the heat on. Have it looked at by a licensed technician, and make sure there is a working carbon monoxide alarm on every level of the home, including the level the furnace is on. The conditions that mean stop now.

What the rollout switch does

Rollout switches are manual-reset thermal limits mounted at the burner opening, outside the combustion chamber. They trip when flame or hot gas rolls out of the burner box toward the front of the furnace instead of being drawn through the heat exchanger and up the flue. Most are one-time manual reset by design, so that a tripped rollout cannot clear itself and hide.

Why one part produces several different codes

A rollout trip means combustion products went somewhere they should not. The usual causes are a blocked or restricted heat exchanger, a cracked heat exchanger, a blocked flue or vent, a failed inducer, or a burner problem sending flame forward. On some controls the same flash count also covers a blown control module fuse, so the code alone does not always mean rollout — check which model the code table applies to.

Every rollout switch code on this site

10 codes across 9 control families. The meaning is the manufacturer's, from the document listed at the foot of each code page.

BrandCodeWhat it reports
Armstrong8 flashesRollout switch open
CarrierStatus code 33Limit circuit fault — a limit or flame rollout switch is open
Goodman6 flashesRollout switch has tripped
Goodman6 flashesRollout limit open, or control module fuse blown
GoodmanEdRollout switch has tripped
Goodman5 red flashesOpen rollout switch, or open fuse detected
LennoxAlert code 200Rollout limit switch open
LennoxE200Hard lockout — rollout circuit open
TraneE04Open limit — thermal, rollout, or reverse airflow switch
York5 red flashesOpen rollout switch

Before you work on it

This is the code most directly associated with carbon monoxide entering the living space. Resetting a rollout switch and running the furnace without finding why it tripped can put combustion products into the house. It needs a licensed technician, and a working CO alarm on every level including the one the furnace is on.

What the fixes cost

Rollout is the code family where the part price is the least useful number on the page. The switch itself sits in the repair guide's $150–350 limit-family band — but a rollout switch that tripped almost certainly worked, and the money follows the cause: obstructed heat exchanger passages, a failed draft path, combustion going wrong. Those findings range from a cleaning-and-correction visit to the worst line on the price sheet, a compromised heat exchanger at $1,000–2,500+, the point where the replacement math usually wins. Price skepticism runs opposite to normal here: be warier of a cheap quote than an expensive one, because a cheap fix on a rollout code usually means nobody found the cause.

Do it yourself or call someone?

There is no homeowner half of this one. The switch is manual-reset by design, so that a person must establish why flame escaped the burner compartment before the furnace runs again; pressing it and retrying is the exact behaviour the design exists to prevent. Leave the furnace off and call. Treat working CO alarms on every level — including the furnace's — as part of the repair rather than an accessory, and treat a fix that arrives without a stated cause for the trip as unfinished work.

Other parts

Sources

Every code meaning above comes from the manufacturer document behind its code page:

This site is a reference, not a substitute for a licensed HVAC technician. Gas appliances can leak carbon monoxide and cause fire. Anything involving gas lines, the heat exchanger, or the flame sensing circuit should be handled by a licensed professional. Pages are written with AI assistance from the sources listed on each page and checked against them before publishing.