Field reference for fire alarm and life safety technicians. 56 entries, taken from the LoopWatt app.
These notes are the web copy of the LoopWatt reference, built for fire alarm and life safety technicians. The same library is free inside the app, with no time limit and no account, and it works with no signal.
Reference notes from LoopWatt, the offline field toolkit for fire alarm and life safety technicians. It works with no cell signal, because the sites do not have any.
Get LoopWatt on the App StoreDevice troubles report by loop and address with a point label
Invalid reply usually means a device answered incorrectly: check for duplicate addresses or a swapped device type
Charger and ground fault troubles are panel level events on the system trouble list
Read status to view points without changing anything
History buffer holds events; walk test enabled per loop or zone
Program changes need the panel password and often VeriFire Tools on a laptop
NFS and NFW series addressable panels; ONYX line. FlashScan and CLIP polling protocols.
Device
The device, module or detector, is not answering the panel's poll. The panel is calling that address and nothing is coming back.
Note the loop and address from the point label; that tells you where to walk before you touch anything
Check the device is physically present and seated in its base, since a detector twisted loose during cleaning is the single most common cause
Check the address setting on the device matches what is programmed, particularly if it was recently replaced
Check for a break in the SLC between the last answering address and this one; devices downstream failing together points at the wire rather than the device
Check terminations at the device and at the previous device on the loop for a loose or backed out screw
Swap in a known good device of the same type at the same address to separate device from wiring
If several addresses in a run go quiet together, treat it as an open circuit on the SLC rather than device failures
Device
The device answered, but with a reply the panel did not expect. Something is on the loop talking out of turn or answering wrongly.
Check for a duplicate address first, because two devices answering the same poll is the classic cause and it produces intermittent, moving faults
Check the device type programmed against the device actually installed; a photo head in a slot programmed for a heat will reply wrongly
Check whether the device was recently replaced with a different model or FlashScan generation
Check the panel is in the correct polling protocol for the devices fitted, FlashScan against CLIP
Check for water or corrosion at the device and its base, which can corrupt the reply
Remove the suspect device and see whether the trouble follows it or stays at the address
Device
The detector is dirty and needs cleaning. This is an early warning, not a failure, and the panel is telling you before it becomes a false alarm.
Note the address and get it on the maintenance list rather than treating it as an emergency
Check what is around that detector: recent construction, drywall dust, a kitchen, a loading dock, or a return air path
Clean the detector per the manufacturer procedure rather than blowing it out with compressed air
Run a sensitivity report after cleaning to confirm it came back into range
If the same head dirties repeatedly, the location is the problem, not the detector; consider whether the device type suits the environment
Device
The detector requires cleaning immediately and is a false alarm risk. Notifier escalates to this when the compensation has run out of headroom.
Treat this as needing action now, because the next event may be an unwanted alarm at three in the morning
Clean or replace the head per the manufacturer procedure
Run a sensitivity report and confirm the reading is back within the listed range, since NFPA 72 requires sensitivity to be within the listed range
Record the sensitivity result, because that record is what an inspection asks for
If it returns to DIRTY 2 quickly, replace the head rather than cleaning it again
Check the environment before reinstalling, since a head that dirties fast is usually telling you about the room
Device
A module has an open circuit on its supervised wiring. The supervision current cannot complete its path on that module's circuit.
Identify which module and which circuit from the point label
Check the end of line resistor is present and the correct value, because a missing or wrong EOL is the most common cause
Check terminations at the module and at the last device on that circuit
Check for a device removed for service and not put back
Measure the circuit from the module with the panel connection lifted and compare against the expected EOL value
Walk the circuit for damaged cable, especially anywhere recent trade work has happened above ceilings
Device
A module has a short circuit on its supervised wiring. On a notification circuit this means the appliances will not sound when called.
Identify the module and circuit from the point label
Lift the circuit at the module and measure; a dead short with the circuit lifted puts the fault in the field wiring
Check for a pinched or skinned conductor at a back box, which is where most shorts are found
Check for water in a box or device, particularly on exterior or parking structure circuits
Split the circuit at a midpoint device and measure each half to halve the search area, and once a half is disconnected leave it disconnected
Check any device added or replaced recently on that circuit
Device
A ground fault on the main or auxiliary power supply. Fire alarm circuits use two conductors with no dedicated ground, so a conductor has found an unintended path to a grounded surface.
Do not leave the system impaired: notify the authority having jurisdiction and the monitoring company, place the system on test, and post a fire watch if required
Check the panel event history first to see when it started and what else happened at that time
Rule out the panel itself by disconnecting field circuits one at a time; if the trouble clears, the fault is out on that circuit
Walk the suspect circuit against the usual suspects: water at a ceiling detector, a pinched conductor at a back box, a screw driven through cable, exterior devices after rain
Split the faulted circuit at a reachable midpoint, and once a section is removed leave it removed, because faults can sit on more than one section and restoring as you go makes it look like it never clears
With the section fully isolated and all electronics removed, measure each conductor to ground with an ohmmeter before reaching for an insulation tester
Never megger a circuit with devices connected
Device
The point has been disabled. Somebody took it out of service deliberately, and it is not protecting anything while it stays that way.
Find out who disabled it and why before enabling anything, because it may be disabled for a reason such as construction dust
Check the panel history for when it was disabled
Check whether a fire watch or impairment procedure is in place if the point covers a required area
Enable the point once the reason is resolved and confirm it returns to normal
Record the disable and enable, since points left disabled are a common inspection finding
Device
An address fault: a detector or sounder base address mismatch, or an incorrect addressable power supply address.
Check the address set on the device against what the panel expects for that point
Check the sounder base address against its detector, since base and head addressing is a frequent source of this
Check for a duplicate address elsewhere on the loop
Check whether the device was recently swapped and the rotary switches or programming not set
Confirm the addressable power supply address if the fault points at an ACPS
Re address and confirm the point reports normally
Device
The power supply is not working properly. Anything it feeds is at risk of dropping out.
Establish what that supply feeds before anything else, because that is the scope of the impairment
Check the AC feed to the supply and the branch circuit breaker
Check the supply's own indicators and any onboard fuses
Measure the output against its rated voltage under load rather than at rest
Check for a downstream short pulling the supply down; disconnect loads one at a time
Notify the authority having jurisdiction and the monitoring company if the affected area loses protection
Device
The power supply's battery charger is not working properly. The batteries will not be maintained, so the system's standby capability is degrading even while everything looks normal.
Measure the charging voltage at the battery terminals against the manufacturer specification
Check the battery age and date code, because a failed battery can present as a charger fault
Check battery terminals and leads for corrosion and tightness
Load test or replace the batteries if they are beyond their service life, typically around five years
Recheck charging voltage with known good batteries fitted before condemning the charger
Record the battery replacement date, since standby calculations depend on it
Device
The auxiliary power supply's battery charge is low. Standby time is reduced or gone.
Measure the battery voltage at the terminals and compare against specification
Check whether AC was recently lost, since batteries take time to recover after a discharge
Check the charger output, because a low battery with a healthy charger points at the battery and the reverse points at the charger
Check battery age, terminals and leads
Replace batteries as a matched pair, never one of two
Confirm the trouble clears after the charge recovers, and recheck the next day
Device
The auxiliary power supply's battery charge is too high. Overcharging cooks batteries and shortens their life considerably.
Measure the charging voltage at the battery terminals against the manufacturer specification
Check the charger setting or jumper for the battery type fitted, since a setting intended for a different chemistry overcharges
Check ambient temperature at the battery location, because heat raises voltage and accelerates damage
Inspect the batteries for swelling or heat damage and replace any that are distorted
Correct the charger before fitting new batteries, or the new ones will fail the same way
Device
An output module or sounder base has lost its power. The device is present on the loop but has no power to do its job.
Identify the point and what supplies its power, which is often a separate circuit from the SLC
Check the power circuit feeding that device and its fuse or breaker
Check terminations at the device power terminals
Check whether other devices on the same power circuit are also affected, which localises it quickly
Check the supplying power supply for its own trouble
Confirm the device operates after power is restored rather than assuming it
Device
The detector chamber reading is too low, which Notifier treats as a detector malfunction rather than a clean detector.
Replace or clean the head per the manufacturer procedure
Check for a head fitted to the wrong base type
Run a sensitivity report and confirm the reading returns within the listed range
Check whether the device was recently disturbed during other work
Record the sensitivity result for the inspection file
Device
Something has come between a beam detector and its reflector. Beam detectors are line of sight devices and anything crossing the path breaks them.
Look along the beam path before touching the detector, because the answer is usually visible from the floor
Check for recently installed ductwork, signage, racking, decorations or a stacked pallet
Check for a lift, scaffold or scissor lift left parked in the path
Check the reflector is still square and has not been knocked or fogged
Check for condensation or dust film on the lens or reflector
Realign per the manufacturer procedure only after the obstruction is cleared
Device
The carbon monoxide sensing element in a detector has reached its expiration date. CO elements have a fixed service life and stop being listed once past it.
Replace the detector or its CO element; a CO element cannot be cleaned back into service
Check the whole site for other CO heads approaching expiry, since they were usually installed together
Note that CO 6MN is the same message six months earlier and is your chance to order ahead
Record the replacement date so the next expiry is not a surprise
Confirm the point returns to normal and test per the manufacturer procedure
Device
A Heat or Acclimate detector is reading a temperature below its rated range. Common in unheated spaces in winter.
Check the actual temperature at the device location, because the message is usually accurate
Check whether the space is unheated, a freezer, a loading dock, or an attic in cold weather
Check whether heating in that area has failed, since the detector may be reporting a real building problem
Confirm the detector type is rated for the environment; a standard head in a cold space is a design issue rather than a fault
Consider a low temperature rated device if the location is legitimately cold
Device
An auxiliary power supply has lost its AC feed and is running on battery. The clock is now running on standby capacity.
Check the branch circuit breaker feeding that supply, and check it is a dedicated circuit that has not been repurposed
Check the AC connections at the supply
Establish whether the building lost power generally or only this circuit; only this circuit points at a local fault
Check the battery condition, because standby time is only as good as the batteries
Notify the monitoring company if the outage will be prolonged
Confirm the charger begins recovering the batteries once AC returns
System
The main power supply has lost AC. The panel is running on battery and standby time is finite.
Check the dedicated branch circuit breaker for the panel first
Confirm whether the building has lost power generally or just the panel circuit
Check AC terminations at the panel
Note the time, because NFPA 72 standby requirements are expressed in hours and you need to know how long you have
Check the battery condition and age, since a panel with weak batteries will not make its rated standby
Notify the monitoring company and the authority having jurisdiction if the outage will exceed standby capacity
System
The panel reports the battery charge as either excessive or insufficient. It is one message covering both ends.
Measure the battery voltage at the terminals and determine which end of the range you are at, because the fix is opposite in each direction
If low, check the charger output and whether AC was recently lost
If high, check the charger setting for the battery type fitted and the ambient temperature
Check battery age and date code; replace beyond service life rather than chasing the symptom
Replace as a matched pair and record the date
Recalculate standby capacity if the battery size has changed from the original design
System
The main power supply's battery charger has malfunctioned. The panel will run normally on AC and fail when it matters.
Measure charging voltage at the battery terminals against specification
Check the batteries themselves, since a shorted cell can present as a charger fault
Check terminals, leads and fuses in the battery circuit
Fit known good batteries and recheck before condemning the charger
Treat this as urgent despite the system looking normal, because standby protection is gone
Notify the monitoring company if the fault cannot be corrected the same visit
System
The annunciator at address x is not responding. Remote annunciators are how responding fire crews read the system, so this matters beyond the panel room.
Note the annunciator address and its physical location
Check power to the annunciator
Check the communication wiring and terminations at both the annunciator and the panel
Check the address setting on the annunciator matches what is programmed
Check for a duplicate address if more than one annunciator is fitted
Check whether the run passes through an area with recent construction work
Tell the fire department contact if the annunciator serving their entry point is out
System
A device connected at J6 is malfunctioning or its cable is disconnected.
Check what is actually landed on J6 for this installation, since it varies by site
Check the cable is connected at both ends and undamaged
Check power to the connected device
Disconnect the device to determine whether the trouble follows it or stays at the panel
Check the panel history for when it started and what else changed
System
The RAM battery backup is low. That battery preserves the panel's programming and history when power is removed.
Print or export the current programming and history before doing anything, because that is what you stand to lose
Replace the RAM backup battery with the correct part
Verify programming and the event history survived the replacement
Check the date and time afterwards
Record the replacement date, since these have a predictable life
System
The database holding the panel's logic equations is corrupt. Logic equations drive cross zoning, releasing and sequence of operation, so this is not cosmetic.
Do not assume the system will operate as designed, because the logic that makes it do so is the thing reporting corrupt
Notify the authority having jurisdiction and the monitoring company, and consider whether a fire watch is required
Retrieve the current programming file and compare it against your record copy
Check whether a recent programming change or download preceded it
Reload the verified programming from a known good file rather than editing around the corruption
Test the sequence of operation after reloading, not just that the trouble cleared
System
A basic walk test is in progress. This is a status message rather than a fault, but the system is not providing normal protection while it runs.
Confirm somebody is actually testing, because a panel left in walk test is a real impairment
Check the monitoring company knows the system is on test
Check how long it has been running; a walk test left on overnight means the building was unprotected
Take the panel out of walk test when testing finishes and confirm it returns to normal
Record the test in the inspection documentation
System
A drill has been activated. Notification appliances are sounding by command rather than because of an alarm.
Confirm a drill is genuinely intended before silencing anything
Check the monitoring company was notified beforehand so the fire department is not dispatched
Check the occupants have been informed if the building requires it
Restore the panel to normal when the drill ends and confirm all appliances stop
Record the drill, since evacuation drills carry their own documentation requirements
TrueAlarm sensors report almost dirty and dirty service conditions before nuisance level
Card level troubles (loop card, NAC card) list separately from point troubles
Ground faults isolate per power supply or loop card on larger systems, which helps localization
Front panel access levels gate functions; level 3 and up changes state
System reports menu prints sensitivity reports that satisfy the sensitivity test requirement
Walk test by group with or without notification
4007ES, 4010ES, 4100ES addressable platforms; IDNet and MAPNET device protocols; TrueAlarm analog sensing.
Device
The device is not responding on its channel. The panel is polling that address and nothing comes back.
Note the channel and address from the point label before walking anywhere
Check the device is present and fully seated in its base
Check the address matches what is programmed, especially after a replacement
Check whether consecutive addresses went quiet together, because that is a wiring break rather than several device failures
Check terminations at the device and at the previous device on the channel
Swap a known good device of the same type into the address to separate device from wiring
Device
Two devices on the channel have the same address. Both answer the same poll and the panel cannot tell them apart.
Treat this as the cause of any intermittent or wandering faults on that channel, because duplicates present exactly that way
Check any device installed or replaced recently, since a new device left at a default address is the usual source
Pull one suspect device and see whether the duplicate clears, which identifies the pair
Re address the incorrect device and confirm both points report independently
Walk the channel and verify the as built address list against what is actually installed
Device
The channel detects a device programmed as the wrong device type. The panel expects one thing and something else answered.
Check the device physically installed against what the point is programmed as
Check whether a head was swapped for a different type, a photo for a heat or a standard for a TrueAlarm
Check the base type matches the head, since sounder and relay bases change what the panel sees
Either fit the correct device or reprogram the point, but do not leave them disagreeing
Test the point after correcting, since device type drives how it alarms
Device
One or more devices are present on the channel that have not been configured for it. Something is answering that the programming does not know about.
Identify which address is answering unexpectedly
Check whether a device was added during other trade work and never programmed
Check whether a device was moved from another channel and kept its address
Either add it to the programming or remove it, since an unconfigured device is not supervised or annunciated
Update the as built documentation, because this usually means the record is wrong
Device
A short is detected on the channel. Simplex clears this automatically once the short is removed, which makes it useful for confirming a repair.
Lift the channel at the card and measure to confirm the short is in the field wiring rather than the card
Check for a pinched or skinned conductor at a back box, which is where most shorts live
Check for water in a box or device, particularly exterior and parking structure runs
Split the channel at a reachable midpoint and measure each half, and leave a disconnected half disconnected while you work
Check any device added or disturbed recently
The message clearing by itself confirms the repair, so use that rather than guessing
Device
A positive or negative earth fault on the channel. Fire alarm wiring has no dedicated ground, so a conductor has found an unintended path to a grounded surface.
Do not leave the system impaired: notify the authority having jurisdiction and the monitoring company, place the system on test, and post a fire watch if required
Note whether it is the positive or negative side, since Simplex tells you and that halves the search
Check the panel history for when it started and what else happened at that time
Disconnect field channels one at a time to establish whether the fault is on a channel or in the panel
Walk the suspect channel against the usual causes: water at a ceiling device, a pinched conductor, a screw through cable, exterior devices after rain
Split the channel and leave each removed section removed, because faults can sit on more than one section at once
Measure conductor to ground with an ohmmeter before reaching for an insulation tester, and never megger with devices connected
System
The earth fault search diagnostic is running. This is the panel hunting the fault for you, and system processes are suspended while it does.
Let it finish and read the progress on the display, because interrupting it wastes the diagnostic
Understand that system processes are suspended during the search, so the system is impaired while it runs
Confirm the monitoring company knows if the search is being run deliberately
Use the result to target the walk rather than starting a manual hunt
Confirm the system returns to normal processing when the search completes
System
None of the devices configured on the channel are communicating. The whole channel is dark rather than one device.
Check the channel wiring at the card first, because losing every device at once points at the head end
Check the card is seated and powered
Check for a short or open right at the start of the run
Check whether recent work disturbed the channel wiring
Treat the entire channel as unprotected and notify accordingly while it is down
Swap the card only after the wiring is proven
System
The channel cannot detect its controller. Everything on that channel is unavailable.
Check the controller card is seated and powered
Check the card indicators against the manual for the installed firmware
Check the panel history for when the controller dropped out
Power cycle per the manufacturer procedure rather than pulling cards live
Treat the channel as impaired and notify the authority having jurisdiction and the monitoring company
Escalate to Simplex support rather than swapping cards speculatively
System
The IDNAC card is drawing more current than it should. Simplex directs you to check for faults on the circuit.
Check for faults on the circuits fed by that card, which is the manufacturer's own first instruction
Check for a short on any notification circuit, since appliances draw hard into a fault
Disconnect circuits one at a time to find which one is pulling the current
Check for water in an appliance back box on exterior or wet location circuits
Recalculate the load if appliances were added, because an overloaded circuit is a design problem rather than a fault
Correct the overcurrent before attempting to restore power
System
A single signaling line circuit is drawing above its rating.
Identify the channel and what is on it
Check for a short or partial short on that channel
Check for water ingress at devices on the run
Check whether devices were added to the channel without recalculating the load
Disconnect sections progressively to find the section drawing the current
Correct the cause rather than resetting, because the card is protecting itself
System
The IDNAC card is not receiving signal power. Simplex is explicit about the fix: correct the overcurrent, then perform a hardware reset to restore power.
Find and correct the overcurrent condition first, because the card will not restore while the fault is present
Check the circuits the card feeds for shorts
Perform a hardware reset once the fault is cleared, which is the manufacturer's stated procedure
Confirm the card powers up and the circuits report normal
Test the notification appliances afterwards rather than assuming they came back
System
The IDNAC card has been damaged, affecting its ability to communicate and power field appliances. Simplex states plainly that the card must be replaced.
Accept that this one is a replacement rather than a repair, because the manufacturer says so
Treat every notification circuit on that card as out of service and notify the authority having jurisdiction and the monitoring company
Establish whether a fault on the circuits damaged the card, so the replacement does not fail the same way
Check the circuits for shorts or water before fitting a new card
Fully test notification on that card after replacement
Device
A TrueAlarm sensor's average value has reached the dirty threshold. TrueAlarm compensates for gradual contamination and reports when the compensation runs low.
Note the address and schedule the clean rather than treating it as an emergency
Check what is around that sensor: construction dust, a kitchen, a dock door, or a return air path
Clean per the manufacturer procedure rather than using compressed air
Run a sensitivity report afterwards and confirm the sensor is back within its listed range
Record the sensitivity result, because that record is what an inspection asks to see
Device
The sensor's average value has reached the higher threshold. Compensation has run out and the sensor is now a false alarm risk.
Treat this as needing action now, since the next event is likely an unwanted alarm out of hours
Clean or replace the sensor per the manufacturer procedure
Run a sensitivity report and confirm the reading is back within the listed range
Replace rather than clean again if it returns quickly
Look hard at the environment, because a sensor that dirties fast is reporting the room rather than itself
Device
A TrueAlarm sensor close to the dirty threshold can be made to report as though it were already dirty. This exists so you can see what is coming while you are already on site.
Use this deliberately before a maintenance visit to pull up every sensor approaching dirty, so one trip covers them all
Clean the sensors it identifies during the same visit rather than returning later
Run sensitivity reports and record the readings
Remember to turn the feature off afterwards if it was enabled only for planning
Treat a long almost dirty list as an environment question rather than a cleaning schedule question
Device
A CO sensor has reached its expiration. CO sensing elements have a fixed service life and are not listed past it.
Replace the sensor or its CO element, since an expired element cannot be cleaned or reset back into service
Check the rest of the site for CO sensors of the same vintage, because they were usually installed together
Record the replacement date so the next expiry is planned rather than discovered
Test the replacement per the manufacturer procedure and confirm the point returns to normal
Signature devices self diagnose; dirty and internal fault states report per device
Map faults occur when the wired layout no longer matches the learned circuit map: look for added, removed, or rewired devices
Riser and audio troubles separate from point troubles on voice systems
Program and status via the SDU or panel front; mapping is a distinctive EST concept
Test fire groups support walk test
History and status accessible without password; changes gated
EST3, EST4, iO series; Signature series intelligent devices.
Loop troubles report by SLC and point; JumpStart auto programming can mask address mistakes, verify point labels
Ground fault indicated at the main board; isolate by unplugging field circuits
Front panel programming possible on many models without a laptop
Walk test and fire drill from the test menu
History under the event menu
6000 and IFP series addressable; SK and SD device protocols; part of Honeywell.
Addressable troubles list address and type mismatch separately: type mismatch means the wrong device model answered at that address
NAC troubles per circuit; check the EOL value first (4.7k typical)
Front panel programming on most models
Read status shows detector chamber values on addressable heads
Walk test silent or audible from the test menu
MS series conventional, ES and MS addressable (LiteSpeed protocol); Honeywell family, shares concepts with Notifier.
Identify the actual sub brand and model first; concepts follow the sub brand's line
Shared device protocols exist across sub brands but devices are usually brand locked
See the specific sub brand entry
Parent of Notifier, Silent Knight, Fire Lite, Gamewell FCI; also Vista and commercial combo panels.
Device events carry a detailed fault reason (no answer, wrong type, contamination level)
ASA detectors report application specific sensitivity states; contamination reporting is built in
Person machine interface with access levels; commissioning via Zeus or Cerberus tools
Walk test per zone; event memory extensive
Cerberus PRO and Desigo Fire (FC and FV series), legacy MXL and XLS; FDnet and HNET device buses.
EOL 5.1k on many circuits, different from the 4.7k many techs assume
SLC troubles report per point; check polarity on retrofits, some devices are polarity sensitive
Front panel menus with USB programming on newer models
Walk test and one person test modes
PFC and IPA addressable series; AFC conventional; also known for sprinkler supervision products.
E3 networks distribute intelligence; a network trouble can mimic many point troubles, check network nodes first
Velociti devices share behavior with Notifier FlashScan generation
Network configuration via CAMWorks; local read status at each node
History per node and network wide
E3 Series, 7100 legacy; S3 Series; Honeywell family, Velociti and CLIP protocols.
Dual language displays common; troubles list per loop and address
EOL 3.9k typical; verify per model
Front panel walk test; configurator software for programming
Verify Canadian vs US listing differences on retrofit jobs
FX series addressable, FA conventional; common in Canada, uses AP and CLIP compatible protocols on some lines.
LSN bus faults report per segment; loop topology matters (T taps limited)
EOL values differ across product generations; check the manual before condemning a circuit
Programming via RPS or FSP software; limited front panel changes
History and diagnostics from the keypad menus
FPD and Avenar panels; D7024 and FPD 7024 legacy; LSN device bus on newer lines.
Reference notes from LoopWatt, the offline field toolkit for fire alarm and life safety technicians. It works with no cell signal, because the sites do not have any.
Get LoopWatt on the App StoreThese notes are a field aid, not a substitute for the governing codes, the stamped drawings, the authority having jurisdiction, or manufacturer manuals. Verify against the current documentation for your installed equipment.