If nobody hears that a sprinkler system has operated, the outcome is close to the system never having operated at all. That is why TS EN 12845+A2:2026 moves alarm transmission into a separate and normative annex, Annex I. Source: TS EN 12845+A2:2026, Annex I (TS p.158-159 / EN p.155-156), Clause 16 and Annex H.
Annex I is normative
The word "(normative)" appears immediately under the title of Annex I, which means it is a requirement and not a recommendation. The annex consists of two short clauses: I.1 Functions to be monitored and I.2 Alarm levels. The whole annex rests on a single table, Table I.1.
Clause I.1: the alarms specified in this standard shall be connected to an alarm panel in the sprinkler control room or the pump room and shall be transmitted onwards depending on the importance of the alarm. The alarms shall be transmitted to a permanently manned location inside or outside the premises. Type B alarms (technical alarms) may in addition be transmitted to a responsible person (see Clause 20.1) so that immediate corrective action can be taken. Where a direct connection to the fire service exists, it is recommended that the alarm transmission procedure be agreed with the authorities.
There are only two alarm levels: A and B
Clause I.2 (TS p.159 / EN p.156) settles the classification in two lines:
- Level A (fire alarm): signals from water flow alarms and/or alarm valves shall be indicated as a fire alarm. Depending on local conditions, a signal indicating that the sprinkler pump set is running may alternatively be treated as a fault alarm.
- Level B (fault alarm): technical faults which could prevent the system from operating correctly in a fire, such as a power failure, shall be indicated as a fault alarm.
The standard contains no four step (Level 1-4) alarm scheme; the only distinction Annex I recognises is A and B.
Table I.1: alarm types to be transmitted
Table I.1 (TS p.158-159 / EN p.155-156) lists each alarm with both its source clause and its type:
| Alarm | Clause | Type |
|---|---|---|
| Water flow alarm | 16.1.1 | A |
| Low pressure in the town main | 9.2 | B |
| Water flow detector in the pump room | 10.3.2 | A |
| Priming tank low level | 10.6.2.4 | B |
| Electric pump set: on demand | 10.8.5.1 | B |
| Electric pump set: start failure | 10.8.5.1 | B |
| Electric pump set: running | 10.8.5.1 | A |
| Electric pump set: power not available | 10.8.5.1 | B |
| Diesel pump set: automatic mode off | 10.9.2 | B |
| Diesel pump set: start failure | 10.9.2 | B |
| Diesel pump set: running | 10.9.2 | A |
| Diesel pump set: common fault | 10.9.2 | B |
| Trace heating circuits | 11.1.2.3 | B |
| Low pressure: type A pre-action system | 11.4.1.2 | B |
| Low pressure: dry pipe and pre-action systems | 16.2.3 | B |
| Zoned systems: open control valve | D.3.7 | B |
| Zoned systems: partly closed control valve | D.3.7 | B |
| Zoned systems: partly open subsidiary valve | D.3.7 | B |
| Zoned systems: low main pressure | D.3.7 | B |
| Zoned systems: water flow in the installation | D.3.7 | A |
| Zoned systems: water flow in the zone | D.3.7 | A |
| Monitored sprinkler systems: partly closed stop valves | Annex H | B |
| Monitored sprinkler systems: liquid levels | Annex H | B |
| Monitored sprinkler systems: low pressure | Annex H | B |
| Monitored sprinkler systems: power failure | Annex H | B |
| Monitored sprinkler systems: low temperature in the pump room | Annex H | B |
The point to watch in the table is the correct clause numbers for the pump alarms: 10.8.5.1 for the electric pump set and 10.9.2 for the diesel pump set. Clause 10.8.5.1 (TS p.68 / EN p.65) lists four conditions to be monitored: power available to the motor (on all three phases where alternating current is used), pump on demand, pump running, and start failure. On the diesel side, Clause 10.9.2 (TS p.69 / EN p.66) lists four indicator lights: pump running, start failure, common faults, and automatic mode off; these shall be indicated both locally and at a location permanently attended by responsible personnel.
The equipment producing the alarm: Clause 16
Annex I governs transmission; Clause 16 defines the equipment producing the alarm:
- Clause 16.1.1 (TS p.113 / EN p.110): each control valve set shall be fitted with a water motor alarm complying with EN 12259-4 and an electrical device for remote alarm indication; both are located as close as possible to the alarm valve. A single common alarm motor and gong may be fitted to a group of wet alarm valves in the same valve room, but an indicator showing which one has operated is provided at each alarm valve. Each water motor alarm gong is marked conspicuously with the installation number.
- Clause 16.1.2: the water motor is installed so that the gong is outside the external wall and its centre line is not more than 6 m above the point of connection to the alarm valve.
- Clause 16.1.3: the pipe to the water motor shall be 20 mm diameter galvanized steel or non-ferrous metallic material, and the equivalent pipe length between the alarm valve and the water motor shall not exceed 25 m, assuming an equivalent length of 2 m for each change of direction.
- Clause 16.2.2 (TS p.113 / EN p.110): water flow alarm switches are used on wet installations only; a test connection simulating the operation of a single sprinkler is fitted downstream of each switch.
- Clause 16.2.3 (TS p.114 / EN p.111): every installation of a dry and pre-action system shall be provided with a low air/gas pressure alarm giving visual and audible warning in accordance with Annex I.
The fire service connection: Clause 16.3
Clause 16.3 (TS p.114 / EN p.111) is directly on point: equipment providing automatic transmission of alarm signals from the sprinkler installation to the fire service or a remote manned centre shall be checkable for:
- a) the continuity of the connection,
- b) the continuity of the connection between the alarm switch and the control unit.
Where there is a direct connection to the fire service, it is recommended that the test procedure be agreed with the authorities in order to avoid false calls.
On the marking side, Clause 18.2.6.1 (TS p.119 / EN p.116) requires a notice stating the fact to be placed adjacent to the alarm test valve wherever water flow into an installation initiates an automatic alarm to the fire service.
Its relationship with Annex H: what are we monitoring?
The last five rows of Annex I refer to Annex H. Annex H (normative, TS p.156-157 / EN p.153-154) sets the general framework for monitoring: all devices used for monitoring shall have a protection of at least IP 54 to EN 60529, and no more than 15 non-addressable supervisory devices shall be connected to a common indicator. All signal and alarm circuits shall be fully supervised and shall give a fault alarm in the event of a short circuit or an open circuit.
The thresholds for the monitored quantities are quantified in Annex H:
- H.2.4 liquid levels: an indication shall be given before the water storage tank level falls by more than 10 per cent of the nominal fill level, and before the fuel level falls by more than 25 per cent of the nominal level. On pressure tanks, an indication is additionally given before the level rises more than 10 per cent above nominal.
- H.2.5 pressures: for town main supplies, an indication is given if the static pressure falls below the calculated working pressure; in all other cases, an indication is given if the static pressure falls by more than 20 per cent of the tested level.
- H.2.7 temperature: the minimum temperature of the sprinkler valve room and the pump room is monitored; an indication is given if the temperature falls below the required minimum.
For the pump room, Clause 10.3.3 (TS p.61 / EN p.58) gives the minimum temperatures: 4 °C for electrically driven pump sets and 10 °C for diesel driven pump sets.
Maintenance: how often is the alarm chain tested?
- Weekly, Clause 20.2.2.3 (TS p.122 / EN p.119): every water motor alarm is sounded for at least 30 seconds.
- Quarterly, Clause 20.3.2.8 (TS p.124 / EN p.121): the flow alarms (flow switches and/or pressure switches) are checked for correct operation.
- Half yearly, Clause 20.3.3.3 (TS p.124 / EN p.121): the electrical installation of the fire service and remote centre alarm is checked.
- Test valves, Clause 15.5.1 (TS p.111 / EN p.108): 15 mm test valves are fitted to test the hydraulic alarm and, where provided, the electrical alarm pressure switch.
Field note: using Table I.1 as a wiring schedule is the habit that saves the most time at commissioning; every row in the table is one contact, and every type letter tells you what colour that contact will show on the panel.
Frequently Asked Questions
How many alarm levels does EN 12845 Annex I define?
Two. Clause I.2 (TS p.159 / EN p.156): signals from water flow alarms and alarm valves are indicated as a fire alarm, which is level A in Table I.1. Technical faults such as a power failure, which could prevent the system from operating correctly in a fire, are indicated as a fault alarm, which is level B. The standard contains no four step alarm scheme numbered 1 to 4.
Which clauses do the electric and diesel pump alarms in Table I.1 refer to?
Table I.1 (TS p.158 / EN p.155): Clause 10.8.5.1 for the electric pump set and Clause 10.9.2 for the diesel pump set. For the electric pump, demand, start failure and power not available are type B, while pump running is type A. For the diesel pump, automatic mode off, start failure and common fault are type B, while pump running is type A.
Where are the alarms transmitted?
Clause I.1 (TS p.158 / EN p.155): the alarms are connected to an alarm panel in the sprinkler control room or the pump room and are transmitted onwards according to their importance. The alarms shall be transmitted to a permanently manned location inside or outside the premises. Type B (technical) alarms may in addition be transmitted to a responsible person so that immediate corrective action can be taken. Where there is a direct connection to the fire service, the alarm transmission procedure should be agreed with the authorities.
Which continuities have to be checkable on a fire service connection?
Clause 16.3 (TS p.114 / EN p.111): equipment providing automatic transmission of alarm signals from the sprinkler installation to the fire service or a remote manned centre shall be checkable for the continuity of the connection and for the continuity of the connection between the alarm switch and the control unit. Where there is a direct connection to the fire service, the test procedure should be agreed with the authorities in order to avoid false calls.
How often is this alarm installation inspected?
Clause 20.3.3.3 (TS p.124 / EN p.121): the electrical installation of the fire service and remote centre alarm is checked at intervals not exceeding 6 months. In addition, Clause 20.2.2.3 requires every water motor alarm to be sounded for at least 30 seconds weekly, and Clause 20.3.2.8 requires the correct operation of the flow alarms to be checked in the quarterly routine.
References
- TS EN 12845+A2:2026 Annex I, Clause I.1, Table I.1, Clause I.2 (TS p.158-159 / EN p.155-156)
- TS EN 12845+A2:2026 Clause 9.2 (TS p.49 / EN p.46)
- TS EN 12845+A2:2026 Clause 10.3.2, Clause 10.3.3 (TS p.61 / EN p.58)
- TS EN 12845+A2:2026 Clause 10.6.2.4 (TS p.63 / EN p.60)
- TS EN 12845+A2:2026 Clause 10.8.5.1 (TS p.68 / EN p.65)
- TS EN 12845+A2:2026 Clause 10.9.2 (TS p.69 / EN p.66)
- TS EN 12845+A2:2026 Clause 11.1.2.3 (TS p.69 / EN p.66), Clause 11.4.1.2 (TS p.71 / EN p.68)
- TS EN 12845+A2:2026 Clause 15.5.1 (TS p.111 / EN p.108)
- TS EN 12845+A2:2026 Clauses 16.1.1, 16.1.2, 16.1.3, 16.2.2 (TS p.113 / EN p.110)
- TS EN 12845+A2:2026 Clause 16.2.3, Clause 16.3 (TS p.114 / EN p.111)
- TS EN 12845+A2:2026 Clause 18.2.6.1 (TS p.119 / EN p.116)
- TS EN 12845+A2:2026 Clause 20.2.2.3 (TS p.122 / EN p.119), Clauses 20.3.2.8 and 20.3.3.3 (TS p.124 / EN p.121)
- TS EN 12845+A2:2026 Annex H, Clauses H.2.4, H.2.5, H.2.7 (TS p.156-157 / EN p.153-154)
- TS EN 12845+A2:2026 Clause D.3.7 (TS p.140 / EN p.137)
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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.