Source: TS EN 12845+A2:2026, Annex J (informative) "Precautions and procedures when a system is not fully operational", J.1 and J.2 (EN p.157), the continuation of J.2, J.3, J.4.1 and J.4.2 (EN p.158).
Annex J is informative, which is why its provisions are written in the "should" form (recommended). The annex consists of four clauses: J.1 Minimizing the effects, J.2 Planned shut-down, J.3 Unplanned shut-down, J.4 Action following sprinkler operation. Clause 20.1.3 (EN p.118) points directly to Annex J for the precautions to be taken during maintenance.
J.1 Minimizing the effects
The opening of Clause J.1 (EN p.157): maintenance, alterations and repair of systems which are not fully operational should be carried out so as to minimize the time and extent of non-operation.
When an installation is rendered inoperative, the user should implement the following measures (10 items, a) to j)):
| Item | Measure |
|---|---|
| a) | The authorities and any central monitoring station should be informed |
| b) | Alterations and repairs to an installation or its water supply (except where Annex F has been applied) should be carried out during normal working hours |
| c) | Supervisory staff in the areas affected should be notified and the area should be patrolled continuously |
| d) | Any hot work should be subject to a permit system. Smoking and naked lights should be prohibited in the affected areas during the progress of the work |
| e) | When an installation remains inoperative outside working hours, all fire doors and fire shutters should remain closed |
| f) | Fire extinguishing appliances should be kept in readiness, with trained personnel available to handle them |
| g) | As much as possible of the installation should be retained in an operative condition by blanking off the pipework feeding the part or parts where work is taking place |
| h) | In the case of manufacturing premises, when the alterations or repairs are extensive, or it is necessary to disconnect a pipe exceeding 40 mm nominal diameter, or to overhaul or remove a main stop valve, alarm valve or non-return valve, every effort should be made to carry out the work while the machinery is stopped |
| i) | Any pump set which is out of commission should be isolated by means of the valves provided |
| j) | Where possible, parts of installations should be reinstated to provide some protection overnight by using blinders and blanks within the pipework; the blinders and blanks should be fitted with visible indicator tags, numbered and logged, to aid timely removal |
Source: Clause J.1 a)-j), EN p.157.
Annex F, referred to in Clause J.1 b) (normative, EN p.143-144), sets out additional measures that increase the reliability and availability of the system. Clause F.8 (EN p.144) gives additional precautions for maintenance: only one zone of a multi-zone installation is shut down at a time; an installation or zone is shut down for the minimum time necessary for maintenance; partial or complete shut-down is avoided wherever possible and only the smallest part of the installation necessary is isolated.
J.2 Planned shut-down
Clause J.2 (EN p.157-158):
- Only the user should give permission for a sprinkler installation or zone to be shut down for any reason other than an emergency.
- Before a system is wholly or partly shut down, every part of the premises should be checked to ensure that there is no indication of fire.
- Where the premises are subdivided into separate occupancies constituting buildings in communication or at risk, protected by common sprinkler systems or installations, all occupiers should be advised that the water is to be turned off.
- Particular attention should be given to situations where the installation pipework passes through walls or ceilings and could from there feed sprinklers in areas needing special consideration.
J.3 Unplanned shut-down
Clause J.3 (EN p.158): when an installation is rendered inoperative as a matter of urgency or by accident, the precautions in J.1 should be observed as far as they are applicable and with the least possible delay. The authorities concerned should also be notified as soon as is possible.
J.4 Action following sprinkler operation
J.4.1 General
Clause J.4.1 (EN p.158):
- Following shut-down after operation of an installation, the operated sprinkler heads should be replaced by heads of the correct type and temperature rating and the water supply should be restored.
- Unopened sprinklers around the area in which operation took place should be checked for damage by heat or other cause and replaced as necessary.
- The water to an installation or zone of an installation that has operated should not be shut off until all fire has been extinguished.
- The decision to shut down an installation or zone which has operated because of a fire should be taken only by the fire service.
- Components removed from the system should be retained by the user so that they can be examined by an authority.
Clause 20.1.4 (EN p.118-119) gives numbers for the stock of spare sprinklers: per system, at least 6 for LH, 24 for OH and 36 for HHP and HHS; the stock is to be replenished promptly after spares are used, and the spares cabinet is to be in a prominent and easily accessible position where the ambient temperature does not exceed 27 C.
J.4.2 Installations protecting cold storage warehouses
Clause J.4.2 (EN p.158) is a single sentence: "The installation should be dismantled for drying out after each operation" (for cold storage warehouses with air circulation refrigeration).
What the standard does not say in Annex J
- A numbered eight-step procedure. J.1 is a 10-item list of measures from a) to j).
- A colour-coded ("yellow / red / green") out-of-service tag system. J.1 j) only recommends that blinders and blanks be fitted with numbered, logged, visible indicator tags.
- A time interval for patrols. J.1 c) says "continuously".
- An outright ban on hot work. J.1 d) requires a permit system; only smoking and naked lights are prohibited.
- A limit on fire watch duty time, a monitoring period after hot work, or a radius of the area to be cleared.
- A requirement to call the insurer within a given time. J.1 a) gives no time limit.
- A record retention period.
- An itemized checklist for returning the system to service. J.4 contains no such list.
Field note
Field note (this is engineering interpretation, not part of the standard): the fact that Annex J is informative does not mean it will not be applied on site; the user's obligation is tied to the normative body of the standard through Clause 20.1.3. In practice the two items with the greatest effect are carrying out the work during normal working hours and keeping as much of the installation as possible operative by blanking off; both reduce the area shut down rather than the duration of the shut-down.
Frequently Asked Questions
What precautions are taken when a sprinkler installation is out of service?
TS EN 12845+A2:2026 Clause J.1 (EN p.157) does not give a numbered procedure but a 10-item list of measures from a) to j): the authorities and any central monitoring station are informed; alterations and repairs are carried out during normal working hours; supervisory staff in the areas affected are notified and the area is patrolled continuously; any hot work is subject to a permit system; outside working hours all fire doors and fire shutters remain closed; fire extinguishing appliances are kept ready with trained personnel; the parts not being worked on are kept operative by blanking off pipework; machinery is stopped for extensive work; any pump set out of commission is isolated; blinders and blanks are marked with numbered and logged indicator tags.
How often is the affected area patrolled while out of service?
Clause J.1 c) (EN p.157) gives no interval: supervisory staff in the areas affected should be notified and the area should be patrolled continuously.
Is hot work prohibited while the system is shut down?
Clause J.1 d) (EN p.157): any hot work should be subject to a permit system. Smoking and naked lights, on the other hand, should be prohibited in the affected areas during the progress of the work.
Who gives permission to shut down an installation?
Clause J.2 (EN p.157): only the user should give permission for a sprinkler installation or zone to be shut down for any reason other than an emergency. Before a system is wholly or partly shut down, every part of the premises should be checked to ensure that there is no indication of fire.
When is the water shut off after a sprinkler has operated?
Clause J.4.1 (EN p.158): the water to an installation or zone of an installation that has operated should not be shut off until all fire has been extinguished. The decision to shut down an installation or zone which has operated because of a fire should be taken only by the fire service.
Is there an extra rule for cold storage warehouse installations?
Clause J.4.2 (EN p.158): installations protecting cold storage warehouses (air circulation refrigeration) should be dismantled for drying out after each operation.
References
- TS EN 12845+A2:2026 Clause J.1 a)-j) and J.2 (EN p.157)
- TS EN 12845+A2:2026 Clause J.2 continued, J.3, J.4.1, J.4.2 (EN p.158)
- TS EN 12845+A2:2026 Clause F.8 (EN p.144)
- TS EN 12845+A2:2026 Clauses 20.1.3 and 20.1.4 (EN p.118-119)
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Download MEP Calc on the App StoreTS EN 12845+A2:2026 (EN 12845:2015+A2:2026) Fixed firefighting systems — Automatic sprinkler systems — Design, installation and maintenance; TS EN 12845-2:2025 (EN 12845-2:2024) ESFR and CMSA sprinkler systems. Every figure in this article is taken from the published standard text; clause, table and page references are listed under References. General information only, not a substitute for the standard or for a design review.