Do not remove, isolate or replace fire alarm devices without controlling the impairment
Confirm the affected area, record the panel information and follow the site fire procedure. Device testing, addressing and loop fault finding should be completed by a competent fire-alarm engineer using compatible equipment.
MOST LIKELY CAUSES
Start with the device and panel information
Symptom variations Match the exact device, address and loop behaviour. ⌄
- Duplicate address message
- Two locations appear under one address
- Device text changes unexpectedly
- Intermittent communication or missing device
- Fault starts after replacement work
Safe first checks Checks for authorised site staff before engineering work. ⌄
- Record the exact loop, address, zone and device text.
- Check whether the device is physically present and visibly undamaged.
- Review recent decorating, ceiling or electrical work.
- Check whether one device or a group of devices is affected.
- Do not leave a detector or call point removed or disabled without formal controls.
Step 1 — Record the duplicated address Follow the site fire procedure and do not leave devices isolated without formal impairment controls. ⌄
Note the loop, address and any device text shown.
Step 2 — Check recent additions or replacements Follow the site fire procedure and do not leave devices isolated without formal impairment controls. ⌄
The most recently changed device is a common starting point.
Step 3 — Do not randomly change addresses Follow the site fire procedure and do not leave devices isolated without formal impairment controls. ⌄
Preserve the configured device list and as-fitted records.
What the indication usually means How this device or loop condition develops. ⌄
A duplicate address fault occurs when two devices on the same loop or network segment respond using the same programmed address.
Engineer diagnostic sequence Competent-person checks after the site information has been captured. ⌄
- Use loop diagnostics to locate both responders.
- Compare device serial numbers where supported.
- Inspect address switches or programmed addresses.
- Correct the duplicate and update configuration records.
- Confirm every configured address responds from the correct location.
Information and equipment needed Useful items for accurate fault finding. ⌄
- Panel make, model and protocol
- Loop and device schedule
- As-fitted drawings and zone plan
- Manufacturer programming or test tools
- Approved detector and call-point test equipment
Parts that may be involved Components commonly associated with this fault. ⌄
- Address programmer
- Replacement address card or switch assembly
- Compatible device
- Commissioning software
- Updated device schedule
When immediate action is required Conditions that should trigger escalation or an impairment plan. ⌄
- Several devices or a complete loop section are missing.
- The affected area has no suitable detection or manual alarm coverage.
- A call point cannot be restored.
- The fault follows water ingress, fire, impact or cable damage.
- The device type, address or location cannot be confirmed.
- The system cannot be returned to normal after repair.
Frequently asked questions Common detector and device questions. ⌄
Can a dirty detector simply be blown out?
Only where the manufacturer specifically permits an approved cleaning method. Uncontrolled compressed air can damage the chamber or drive contamination further inside.
Can a detector be swapped with another one?
Only with a compatible device and with the addressing method, configuration and test requirements understood.
Does one missing device matter?
Yes. It may leave part of the building without the intended detection or control function.