EN 12845 Weekly Diesel Pump Exercise Test

The weekly diesel pump test is not defined in a single clause of EN 12845 but across the six subheadings of Clause 20.2.2. This article sets out the test steps in the standard's own order and with individual clause references. Source: TS EN 12845+A2:2026, Clause 20.2, EN p.119-120.

The standard gives no tables of numerical "typical ranges" for this test. How many bar the oil pressure should be, how many degrees the cooling water should be, how many volts the battery should be are not provisions of the standard; the standard requires these quantities to be monitored and leaves their values to the supplier and to the pump nameplate. No invented band values appear below.

Interval and scope

Clause 20.2.1 (EN p.119): the installer provides the user with a documented inspection and checking procedure for the system. That programme covers the actions to be taken in the event of faults, the operation of the system, in particular the emergency manual starting procedure for the pumps, and the details of the weekly routine in 20.2.2.

Clause 20.2.2.1 (EN p.119): every part of the weekly routine is carried out at intervals not exceeding 7 days.

Clause 20.1.1 (EN p.118): the user appoints a person, together with a deputy, who after receiving the necessary instructions is responsible for keeping the system in working order. The name, address and telephone number of the responsible person and the deputy are displayed conspicuously in the sprinkler valve room.

Step 1: Checks and recording (20.2.2.2)

The following are checked and recorded:

• a) all water and air pressure gauge readings on installations, main headers and pressure tanks. In dry, alternate and pre-action installations the pressure in the pipework should not fall faster than 1.0 bar per week;
• b) water levels in elevated private reservoirs, rivers, canals, lakes and water storage tanks (including pump priming water tanks and pressure tanks);
• c) the correct position of all main stop valves.

Step 2: Water motor alarm (20.2.2.3)

Each water motor alarm is sounded for at least 30 seconds.

The alarm itself is provided at every control valve set in accordance with Clause 16.1.1 and conforms to EN 12259-4. Clause 16.1.2 (EN p.110) requires the gong to be located on the outside of an external wall and not more than 6 m above the point of connection to the alarm valve, and requires the water outlet to be arranged so that the flow can be seen.

Step 3: Automatic pump set starting test (20.2.2.4)

The tests on automatic pump sets comprise the following:

• a) on diesel engines, the fuel and engine lubricating oil levels are checked;
• b) the water pressure at the starting device is reduced, so that the automatic starting condition is simulated;
• c) when the pump set runs, the starting pressure is checked and recorded;
• d) on diesel pumps, the oil pressure and the cooling water flow in open circuit cooling systems are checked.

The criterion for assessing the recorded starting pressure is in Clause 10.7.5.2 (EN p.63): the first pump set starts automatically before the pressure in the main header falls below 0.8p, where p is the closed valve pressure. Where there are two pump sets, the second starts before the pressure falls below 0.6p. Once started, the pump continues to run until it is stopped manually.

Clause 10.7.5.1 (EN p.63): two pressure switches are provided to start each pump set, the pipe to them is at least 15 mm, and the switches are connected so that either of them will start the pump.

Step 4: Diesel engine restart test (20.2.2.5)

Immediately after the pump set starting test in 20.2.2.4, diesel engines are tested as follows:

• a) the engine is run for 20 minutes or for the period recommended by the supplier. It is then stopped and immediately restarted using the manual start test button;
• b) the water level in the primary circuit of closed circuit cooling systems is checked.

Throughout the test the oil pressure (if a gauge is fitted), engine temperatures and coolant flow are monitored. The oil hoses are checked and a general inspection is made for leakage of fuel, coolant or exhaust gas.

The critical word here is "immediately": the engine is expected to start again while hot, just after being loaded, and with the battery partly discharged. The test is arranged in this order so as to exercise those two conditions together.

Step 5: Heating systems (20.2.2.6)

Heating systems that prevent freezing in the sprinkler system are checked for correct operation. This covers trace heating and space heating.

Neighbouring intervals outside the weekly routine

Recording and returning the system to service

Clause 20.1.2 (EN p.118): the user operates an inspection and checking programme, arranges a test, service and maintenance schedule, and keeps records including a log book held on the premises. The user arranges for the test, service and maintenance schedule to be carried out under contract by the system installer or a similarly qualified firm. After any inspection, check, test, service or maintenance operation, the system together with all automatic pumps, pressure tanks and gravity tanks is returned to the proper operating condition.

Clause 20.3.1.2 (EN p.121): a signed and dated report of the inspection is given to the user; the report includes details of corrections made or required and of external factors (for example weather conditions) that may have affected the results.

Clause 20.1.3 (EN p.118): for the precautions to be taken when the system is not in working order or after a sprinkler has operated, see Annex J.

The same test carried out once at commissioning

Clause 19.1.2 (EN p.117): the system is tested once as specified in 20.2.2 and 20.3.2, that is, the tests to be carried out on a routine weekly and quarterly basis are also carried out at commissioning and any faults found are corrected. Clause 19.1.3 requires the water supplies to be tested once in accordance with 8.6, and diesel engine driven pumps to be tested in accordance with 20.2.2.5.

Field note: the minimum fields to be recorded in the weekly test record can be derived from the standard's own list: pressure gauge readings, water levels, stop valve positions, starting pressure, running time, restart result, alarm duration. Since the standard gives no acceptance band for these fields, the acceptance criterion is the pump nameplate and the supplier data.

Frequently Asked Questions

For how many minutes is the engine run in the EN 12845 weekly diesel pump test?

TS EN 12845+A2:2026 Clause 20.2.2.5 a) (EN p.119): the engine is run for 20 minutes or for the period recommended by the supplier. It is then stopped and immediately restarted using the manual start test button. Every part of the weekly routine is carried out at intervals not exceeding 7 days (Clause 20.2.2.1).

How is the automatic start simulated?

Clause 20.2.2.4 b) (EN p.119): the automatic starting condition is simulated by reducing the water pressure at the starting device. When the pump set runs, the starting pressure is checked and recorded (20.2.2.4 c). Clause 10.7.5.2 (EN p.63) requires the first pump set to start automatically before the pressure in the main header falls below 0.8p, where p is the closed valve pressure, and requires the pump, once started, to continue running until stopped manually.

How long does the water motor alarm test last?

Clause 20.2.2.3 (EN p.119): each water motor alarm is sounded for at least 30 seconds. This is also part of the weekly routine.

Which values are recorded in the weekly test?

Clause 20.2.2.2 (EN p.119): all water and air pressure gauge readings on installations, main headers and pressure tanks; water levels in elevated private reservoirs, rivers, canals, lakes and water storage tanks (including priming tanks and pressure tanks); the correct position of all main stop valves. In addition, the starting pressure is recorded in accordance with 20.2.2.4 c).

What should be done after the test is finished?

Clause 20.1.2 (EN p.118): after any inspection, check, test, service or maintenance operation, the system together with all automatic pumps, pressure tanks and gravity tanks is returned to the proper operating condition. The user also keeps records including a log book, and those records are kept on the premises.

References

• TS EN 12845+A2:2026 Clauses 10.7.5.1, 10.7.5.2 (EN p.63)
• TS EN 12845+A2:2026 Clauses 16.1.1, 16.1.2 (EN p.110)
• TS EN 12845+A2:2026 Clauses 19.1.2, 19.1.3 (EN p.117)
• TS EN 12845+A2:2026 Clauses 20.1.1, 20.1.2, 20.1.3 (EN p.118)
• TS EN 12845+A2:2026 Clauses 20.2.1, 20.2.2.1, 20.2.2.2, 20.2.2.3, 20.2.2.4 (EN p.119)
• TS EN 12845+A2:2026 Clauses 20.2.2.5, 20.2.2.6, 20.2.3 (EN p.119-120)
• TS EN 12845+A2:2026 Clauses 20.3.1.2, 20.3.2.5, 20.3.2.6 (EN p.121)
• TS EN 12845+A2:2026 Clauses 20.3.4.2.1, 20.3.4.3, 20.3.4.5 (EN p.122)

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