EN 12845 Annual, 3 Year and 10 Year Routines: Clauses 20.3.4-20.3.6

Source: TS EN 12845+A2:2026, Clauses 20.3.4, 20.3.5 and 20.3.6 (EN p. 121-122), Clause 21 (EN p. 123) and Annex K (EN p. 159).

The maintenance regime of EN 12845 is layered in Clause 20. This article covers the three long interval layers (annual, 3 year, 10 year) in the standard's own words and also flags the acceptance criteria that are wrongly attributed to these clauses in the market.

The layer map of Clause 20

Clause 20.3.4: the annual routine

Clause 20.3.4.1: "The following checks and inspections shall be carried out at intervals of no more than 12 months."

20.3.4.2.1 Automatic pump set flow test

Each water supply pump set on the installation is tested under full load conditions. The test is carried out through a test line connected downstream of the non-return valve at the outlet of the pump set, and the pump shall deliver the pressure and flow values given on the nameplate. Suitable allowances are deducted for the pressure losses in the supply pipe and the valves between the source and each control valve set.

It has to be said plainly here: the text of TS EN 12845+A2:2026 contains no acceptance table such as the closed valve pressure not exceeding 140 % of the rated pressure or at least 70 % of the rated pressure being achieved at 140 % flow. The annual test criterion of the standard is a single sentence: deliver the nameplate values. Both thresholds were searched for during the review of this article and no counterpart was found in the text of the standard.

20.3.4.2.2 Flow test on a system without pumps

Where the water supply is not provided by a pump, each water supply on the installation is tested under full load conditions through a test line connected upstream of the control valve set, and shall meet the required flow and pressure values. Again, allowances are deducted for the losses in the supply pipe and the valves.

20.3.4.3 Diesel engine failed to start test

The failed to start alarm is tested so as to conform to Clause 10.9.7.2. Immediately after this test the engine is started with the manual starting system.

Note: with amendment A2 the whole of Clause 10.9 has been transferred to EN 17451. In TS EN 12845+A2:2026 only 10.9.1 (general, reference to EN 17451), 10.9.2 (starter alarm indications) and 10.9.3 (commissioning test on site) remain under Clause 10.9 (EN p. 65-66). There is no clause 10.9.7.2 in the text; figures such as the number of attempts, the duration of each attempt and the pause between attempts therefore cannot be read from this standard.

20.3.4.4 and 20.3.4.5

• The float valves on the water storage tanks are checked to ensure that they function correctly.
• The pump set suction screens together with the settling chamber and its screens are inspected at least once a year and cleaned as necessary.

Clause 20.3.5: the 3 year routine

Clause 20.3.5.1: the interval is a maximum of 3 years.

20.3.5.2 Storage and pressure tanks: except for tanks that, being painted or otherwise corrosion protected under Clause 9.6.2 b), do not need to be emptied for maintenance at intervals of less than 10 years, all tanks are inspected internally and, if necessary, emptied and cleaned. They are examined for corrosion in accordance with the manufacturer's recommendations and repainted, or their corrosion protection renewed, as necessary.

20.3.5.3 Water supply stop valves, alarm valves and non-return valves: all water supply stop valves, alarm valves and non-return valves are inspected and, if necessary, replaced or overhauled.

Clause 20.3.6: the 10 year routine

It is a single sentence: at intervals of no more than 10 years all storage tanks are cleaned, inspected internally and their shell repaired as necessary. The NOTE to the clause adds that cleaning tanks normally requires them to be emptied, but that alternative solutions that save water may be acceptable.

The two levels of tank inspection therefore complement each other: an internal inspection and, if necessary, cleaning every 3 years, and a full cleaning and internal inspection every 10 years.

Clause 21 and Annex Q: periodic system inspection

Clause 21 (EN p. 123): the sprinkler system is inspected periodically by a competent person at least once a year (Annex Q). The inspection report assesses the conformity of the system with this standard and its adequacy in terms of maintenance, operation and the risk in question. A list of non conformities is drawn up and acted upon.

Annex Q (informative, EN p. 165) recommends that the periodic inspection be carried out by an independent body, that is, not by the system owner, the building user, the system installer (or a competing installer) or the service and maintenance provider (or a competing provider). A competent person is an individual who has been appointed, suitably trained, is competent through knowledge and practical experience, and has received the necessary instruction to enable the tests to be carried out.

Annex K: the 25 year inspection

Annex K is informative; it recommends the following:

• The pipework is thoroughly flushed and tested hydrostatically at the maximum static pressure or at 12 bar, whichever is the higher.
• The pipework is inspected internally and externally. At least 1 m of range pipe for every 100 sprinklers, and two pipe sections at least 1 m long of each pipe size, are inspected.
• All defects that could adversely affect the performance of the system are corrected.
• In wet pipe systems at least one sprinkler installation per building is checked; where a building has more than one wet control valve set, inspecting 10 % of them is sufficient. No such reduction is allowed for dry pipe systems.
• A number of sprinklers are removed and tested to ensure that they are fully functional.

Table K.1: number of sprinklers of each type present to be tested

The sprinklers are assessed under the following headings: operation, operating temperature, K-factor deviation, spray obstructions, lodgement and thermal sensitivity.

Measures while the system is out of service

Clause 20.1.3 (EN p. 118) refers to Annex J for the measures to be taken while the system is not in working order or after a sprinkler has operated. Since most annual and 3 year work temporarily puts the system out of service, that reference belongs in the work programme. Clause 20.1.2 further requires the system, the automatic pumps, the pressure tanks and the gravity tanks to be returned to the proper operating condition after every inspection, check, test, service or maintenance operation. Clause 20.3.1.2 requires a signed and dated report of each inspection to be given to the user, the report to include the corrections made or required and external factors such as weather conditions that could have affected the result.

Frequently Asked Questions

What is the acceptance criterion in the annual pump test of EN 12845?

Clause 20.3.4.2.1 (EN p. 122): each water supply pump set on the installation is tested under full load conditions through a test line connected downstream of the non-return valve at the pump outlet, and shall deliver the pressure and flow values given on the nameplate. Suitable allowances are deducted for the pressure losses in the supply pipe and the valves between the source and each control valve set. There is no acceptance criterion in the text of TS EN 12845+A2:2026 such as the closed valve pressure not exceeding 140 % of rated pressure, or 70 % of rated pressure being achieved at 140 % flow.

What else is in the annual routine?

Clause 20.3.4 (EN p. 121-122) sets the interval at a maximum of 12 months and lists four further items: the full load flow test of water supplies without pumps, through a test line connected upstream of the control valve set (20.3.4.2.2); testing the failed to start alarm of the diesel engine and immediately afterwards starting the engine with the manual starting system (20.3.4.3); checking that the float valves on the water storage tanks function correctly (20.3.4.4); and inspecting the pump suction screens together with the settling chamber and its screens at least once a year and cleaning them as necessary (20.3.4.5).

What is done in the three year routine?

Clause 20.3.5 (EN p. 122) sets the interval at a maximum of 3 years. 20.3.5.2: except for tanks designed under Clause 9.6.2 b) so that they do not require maintenance within 10 years, all tanks are inspected internally and, if necessary, emptied and cleaned; they are examined for corrosion in accordance with the manufacturer's recommendations and repainted or their corrosion protection renewed as necessary. 20.3.5.3: all water supply stop valves, alarm valves and non-return valves are inspected and, if necessary, replaced or overhauled.

What does the ten year routine cover?

Clause 20.3.6 (EN p. 122): at intervals of no more than 10 years all storage tanks are cleaned, inspected internally and their shell repaired as necessary. The NOTE to the clause states that cleaning tanks normally requires them to be emptied, but that alternative solutions that save water may be acceptable.

Is the 25 year inspection mandatory?

Annex K (EN p. 159) is an informative annex, so it is not mandatory. It recommends that the pipes and sprinklers be inspected after 25 years: the pipework is thoroughly flushed and tested hydrostatically at the maximum static pressure or at 12 bar, whichever is the higher; at least 1 m of range pipe for every 100 sprinklers and two pipe sections at least 1 m long of each pipe size are inspected. In wet pipe systems at least one installation per building is checked; where a building has more than one wet control valve set, inspecting 10 % of them is sufficient, whereas no such reduction is allowed for dry pipe systems. Table K.1 gives the sampling numbers: 20 up to 5 000, 40 up to 10 000, 60 up to 20 000, 80 up to 30 000 and 100 up to 40 000 sprinklers.

How many attempts are made in the failed to start test of the diesel engine?

Clause 20.3.4.3 (EN p. 122) requires the failed to start alarm to be tested in accordance with Clause 10.9.7.2. However, with amendment A2 the whole of Clause 10.9 has been transferred to EN 17451, and the text of TS EN 12845+A2:2026 contains only 10.9.1, 10.9.2 and 10.9.3 (EN p. 65-66); there is no clause 10.9.7.2. The number of attempts and their durations therefore cannot be read from the text of this standard, and EN 17451 has to be consulted.

References

• TS EN 12845+A2:2026 Clause 9.6.2 b) (EN p. 56)
• TS EN 12845+A2:2026 Clause 10.9.1, 10.9.2, 10.9.3 (EN p. 65-66)
• TS EN 12845+A2:2026 Clause 20.1.2, 20.1.3 (EN p. 118)
• TS EN 12845+A2:2026 Clause 20.2.2, 20.2.3 (EN p. 119-120)
• TS EN 12845+A2:2026 Clause 20.3.1.2, 20.3.2, 20.3.3, 20.3.4.1 (EN p. 120-121)
• TS EN 12845+A2:2026 Clause 20.3.4.2.1, 20.3.4.2.2, 20.3.4.3, 20.3.4.4, 20.3.4.5 (EN p. 122)
• TS EN 12845+A2:2026 Clause 20.3.5.1, 20.3.5.2, 20.3.5.3, 20.3.6 (EN p. 122)
• TS EN 12845+A2:2026 Clause 21 (EN p. 123)
• TS EN 12845+A2:2026 Annex K, Table K.1 (EN p. 159)
• TS EN 12845+A2:2026 Annex Q (EN p. 165)

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