No automatic shutoff switch at furnace service panel.

[Luc V. L.]

Is an automatic shutoff button/ sensor required to be installed to shut off a furnace when the service panel/ cover is removed or is this just a bonus safety feature? I inspected a modern Carrier gas furnace in an attic space today that did not have this feature.

[Markus Keller]

A couple of notes on this question. A modern Carrier without a cut-off switch is very suspicious.
Which cover did you take off, the burner cover or the blower compartment cover? The burner compartment cover does not have a cut-off switch. However I have yet to see a blower compartment that doesn't come with a factory cut-off switch.
If you you are talking about the blower compartment, write it up as an issue. Did you see non-standard wiring connections?

[Luc V. L.]

I was referring to the burner compartment door. Why do some gas furnaces install auto shutoffs for the burner compartment and others not?
The wiring looked appropriate.

[Ken Rowe]

Here in MN the blower door switch is required on all furnaces. However, a certified HVAC technician can remove them if they deem it is necessary.

[Bob Elliott]

It also depends on the style.
The carriers with that top knurled hand screw have the one long cover and then you need to go down and unscrew the inside sheet metal cover for the blower at bottom.

[Vern Heiler]

Just a side note that could save you $79.

I was in the attic when the furnace was running and the thermostat satisfied. When I put the burner cover back on the fan cover jiggled and the switch opened. A lot of the switch brackets are bent and are on the edge of not working.

The owner had to call HVAC that evening because she had no heat. $79 service call that I had to swallow.

Now I run the fan before I leave if I have any doubt about the switch!