Concept · Zone F · Alarm devices
Smoke detectors and heat detectors: where each belongs and who services them
The Study Material names four types of smoke detector and two types of heat detector. Smoke detectors sense particles of combustion, visible or invisible. Heat detectors sense an abnormally high temperature or a fast rise in temperature. Pull stations, CO detectors and water flow switches are the other ways an alarm starts; see alarm devices.
Plan ref F1Updated October 25, 2026
Two ways to sense a fire
The Study Material gives each smoke detector type one job:
- Area smoke detector: the ordinary ceiling detector.
- Elevator lobby smoke detector: when it activates, it recalls the elevators to the designated landing.
- Beam detector: a light beam across a large area where spot detectors are not practical. Smoke that breaks the beam trips it.
- Duct smoke detector: samples the air in an HVAC duct and shuts down the fan when it activates.
Heat detectors come in two types. One reacts to how fast the room heats up. The other reacts when the room reaches a set temperature. Their figures, and what happens to each one after an alarm, are in the side-by-side table.
Detector or alarm
The Study Material keeps two words apart. A smoke detector is connected to the fire alarm control panel. A smoke alarm is self-contained, with its own sensor, sounder and power, and is not connected to a system (Source: Study Material §2). Detectors can also trip with no fire; the unnecessary vs unwarranted alarms page sorts those cases.
Detector checkpoints
Checkpoint round
0 of 6 checked · 0 cleared
Practice questions written for study, not taken from the test. The real F-80 is a multiple-choice test on a touch-screen computer at FDNY Headquarters.
Read the four options before the stem. Wrong ones here tend to swap the detector type, the person or the cause; find what differs between them first.
How the checkpoint round works
Read the options first and rule out the ones that break a rule, then pick from what is left. After you answer, the debrief explains every option and scores your strikes. Keys: 1–5 or A–E answer, Shift with a number rules that option out, the arrow keys move.
Checkpoint 1 of 6
Checkpoint 01
A heat detector in a shelter gym keeps getting hit by balls. What does the Study Material require?
Rule out what you can with the ✕ buttons, then choose. The debrief for every option opens here.
- ACorrect: Where a heat detector is subject to mechanical damage, it must be protected by an approved UL/FM guard, which also makes tampering harder.
- BChanging the detector type is not the Study Material’s answer to physical damage; a guard is.
- CCovering a detector stops it from working; detectors are never covered.
- DTaking it out of service creates an impairment; the fix is to protect it so it keeps working.
Checkpoint 02
On patrol, the coordinator finds a heat detector in the laundry room hanging loose and not working. Who must the coordinator notify?
Rule out what you can with the ✕ buttons, then choose. The debrief for every option opens here.
- ACorrect: The coordinator makes sure working heat detectors are in place and must notify the fire alarm maintenance company when one is defective or inoperable.
- BThe insurer is told when a system is placed out of service, but a broken detector goes to the alarm maintenance company to fix.
- CHeat detectors are tested and serviced by authorized fire alarm technicians, not the building electrician.
- DThe maker does not service detectors in the building; the fire alarm maintenance company does.
Checkpoint 03
Contractors will sand the floors in a hallway with smoke detectors. What does the Study Material warn about this work?
Rule out what you can with the ✕ buttons, then choose. The debrief for every option opens here.
- ADust in a smoke detector causes an alarm signal, not a trouble signal; that is what makes it a false alarm.
- BCorrect: Sheetrock dust or dust from sanding floors can make smoke detectors signal an alarm when there is none, so they must be protected from it.
- CHeat detectors react to temperature, not dust; dust is a smoke detector problem.
- DAny smoke detector can be set off by dust; the warning covers all of them during renovations.
Checkpoint 04
Which detector sends an alarm when the room temperature rises fast, about 12° to 15°F per minute?
Rule out what you can with the ✕ buttons, then choose. The debrief for every option opens here.
- AA fixed-temperature detector trips when a fusible element melts at a preset temperature, not on how fast the heat climbs.
- BCorrect: a rate-of-rise unit reacts to the speed of the climb (12° to 15°F per minute) and normally self-restores afterward.
- CA beam detector reacts when combustion particles break its light beam; it does not sense temperature.
- DA duct detector samples air in the HVAC duct for combustion particles and shuts down the fan; it does not read heat.
Checkpoint 05
A fixed-temperature heat detector in the kitchen activated during a small fire. What normally has to happen to it afterward?
Rule out what you can with the ✕ buttons, then choose. The debrief for every option opens here.
- ASelf-restoring is what a rate-of-rise detector normally does; a fixed-temperature unit’s melted element cannot reform.
- BA key reset belongs to some manual pull stations, not to a heat detector whose element has melted.
- CPressing reset at the FACP normally clears a smoke detector once the smoke is gone; it cannot repair a melted element.
- DCorrect: its fusible element melted when it tripped, so the unit is normally replaced, and only by an S-97 or S-98 holder.
Checkpoint 06
Smoke detectors in a shelter should be cleaned and maintained every six months. Who should do this work?
Rule out what you can with the ✕ buttons, then choose. The debrief for every option opens here.
- AThe F-80 coordinator makes sure the work happens on schedule, but cleaning and servicing detectors is technician work.
- BCleaning rooms is not detector maintenance; opening and servicing the devices is certified fire alarm work.
- CCorrect: detector cleaning and maintenance is fire alarm service work, so it goes to an S-97 or S-98 holder.
- DThe central station company receives alarm signals and arranges transmitter repairs; it does not clean detectors.
Smoke or heat, side by side
Detector types as the F-80 Study Material describes them (rev. January 2026)
| Point | Smoke detector | Heat detector |
|---|---|---|
| What it senses (differs) | Visible or invisible particles of combustion | An abnormally high temperature, or a fast rise in temperature |
| Types named (differs) | Area, elevator lobby, beam, duct | Rate-of-rise: trips when the room heats 12° to 15°F per minute. Fixed temperature: a fusible element melts at a preset point |
| What the Study Material credits it with (differs) | Reducing fire damage and loss of life | Reducing fire damage |
| After an alarm (differs) | Normally resets when reset is pressed at the FACP, once the cause has cleared | Rate-of-rise normally self-restores. Fixed temperature normally needs replacement by an S-97 or S-98 holder; intelligent units usually reset themselves |
| Who works on it (differs) | Cleaned and maintained every six months by an S-97 or S-98 holder | Tested only by authorized fire alarm technicians; the coordinator calls the maintenance company when one is defective |
| Protection (differs) | Keep airborne particles out at all times, especially during construction | Where damage or tampering is a risk, an approved mechanical guard |
Shaded rows marked ≠ are the points where Smoke detector and Heat detector differ.
From Source: Study Material §10.1 and Source: Study Material §10.3.
Look, log and call; do not modify
F-80 holders may do visual inspections of initiating devices and keep the log books. Only S-97 or S-98 holders service and test the fire alarm system (Source: Study Material §2). The coordinator may not install or modify alarm components (Source: Study Material §10). The same limit applies to the device people trigger by hand: see manual pull stations.
Key takeaways
- Smoke detectors sense particles of combustion; heat detectors sense temperature.
- Four smoke types: area, elevator lobby, beam, duct. Two heat types: rate-of-rise, fixed temperature.
- Rate-of-rise means a fast climb in temperature and no replacement. Fixed temperature means a melted element.
- A detector is wired to the panel. A smoke alarm stands alone.
- Service and testing belong to S-97 or S-98 holders. The F-80 holder looks, logs and calls.
Next exit: the App Store
F-80 is on the App Store for iPhone and iPad. On any other device, the free practice here is the way through.