In brief
Under Annex III, steam boilers undergo periodic inspection at least once a year; from 1 January 2027 this inspection will be carried out by an equipment inspection body rather than a single authorised person. Boiler safety, however, depends more on daily operation than on the report: the safety valve, water level protection, boiler room layout and a certified operator. Under the MYK communiqué, the certification requirement for steam boiler operators starts on 23 March 2027.
Steam boiler safety: where does the risk come from?
A steam boiler is a pressure vessel that holds a large amount of thermal energy under pressure. Steam boiler safety therefore rests on two questions: can the pressure rise uncontrollably, and can the heating surfaces run dry? When the water level falls, the surfaces in contact with the flame overheat and the material weakens; if the safety devices are disabled, the outcome can go as far as the boiler shell rupturing. On top of this come fuel and combustion risks and the fire load in the boiler room.
In Bursa, steam boilers are widely used in textile dyeing and finishing plants, food production and chemical businesses; TOSAB Bursa Tekstil Boyahaneleri İhtisas OSB in Nilüfer is a zone where dye houses are clustered together. This article covers the daily operation of your boiler, the boiler room and the inspection regime that will change in 2027.
Safety devices: what should be checked in operation?
The boiler's design and manufacturing standard determines which devices must be fitted. What the business must do is regularly confirm that these devices work and record it:
| Device | Function | Check in operation |
|---|---|---|
| Safety valve | Discharges steam when the set pressure is exceeded | Is the seal intact, does the discharge pipe vent to a safe place, has a weight or lock been fitted to the valve? |
| Pressure gauge | Shows boiler pressure | Is it legible, is the operating pressure marked, is calibration up to date? |
| Water level gauges | Show the water level in the boiler | Is the glass clean, are the cocks open, does blowdown confirm the level is shown correctly? |
| Low water level cut-out | Stops the burner when the level falls | Is a function test carried out according to the manufacturer's instructions? |
| Pressure switches | Stop the burner at working pressure | Are the set values labelled and unchanged? |
| Flame monitoring | Cuts the fuel if the flame goes out | Are fault records reviewed? |
| Blowdown valves | Remove sludge and salt build-up | Is blowdown carried out regularly and recorded? |
Annex III requires safety valves and similar safety devices on pressure equipment with a defined operating pressure to be set in line with that pressure. For equipment such as steam boilers whose standard includes a safety valve test, safety valves are tested within the maximum intervals set out in the standard. Do not neglect water treatment either: a scaled heating surface can overheat even when the water level is correct.
The operator's shift check
Annex III requires work equipment to be visually inspected by its operator before each start of work, its functions to be tested and this to be recorded. For a steam boiler, turn this check into a simple shift log:
- Read and record pressure and water level at the start of the shift and at set intervals.
- Check the water level gauges by blowdown; if the two gauges show different levels, do not operate the boiler until you find the cause.
- Confirm that the feed water pump, softening unit and chemical dosing system are working.
- Note burner fault and safety trip records; report recurring faults to the maintenance team.
- Look for steam, water or fuel leaks and any unusual noise or vibration.
- Check that the boiler room doors, the extinguisher and the gas detector are in place.
This log shows the boiler's operating history to the person carrying out the annual inspection and is the first document examined in a post-accident investigation.
Boiler room safety
The structural requirements for boiler rooms are set out in Articles 54 and 55 of the Regulation on the Protection of Buildings from Fire. The points to check most often in inspections and daily operation are:
- The boiler room is separated from the rest of the building by partitions with at least 120 minutes of fire resistance.
- Boiler rooms with a thermal capacity above 350 kW or a floor area above 100 m² have at least 2 exit doors. The doors should, as far as possible, face opposite directions, have at least 90 minutes of fire resistance, be smoke-tight and self-closing.
- The boiler room door does not open directly onto an escape stair or a general-use stair.
- At least one 6 kg multi-purpose dry chemical powder extinguisher is kept in the boiler room.
- If natural gas or LPG is used, meters are placed outside the boiler room; the main gas shut-off valve and the main electrical panel are outside the room in an easily accessible place; a gas detector is mandatory.
- Boiler rooms using LPG cannot be located in a basement.
There is one more problem the legislation does not mention but we see often on site: using the boiler room as a storeroom. Packaging, oil drums or chemicals left around the boiler both increase the fire load and block the escape route. Only authorised staff should enter the boiler room, and the door should not be left open without control.
How is periodic inspection carried out today?
Under Annex III Table 1 of the Regulation on Health and Safety Requirements for the Use of Work Equipment, periodic inspection of steam and superheated water boilers is carried out at least once a year unless the standards set a shorter interval. The inspection criteria come from the TS EN 12952 series, the TS EN 12953 series and the TS 497 series of standards. Testing has two layers:
- At every periodic inspection (at most once a year): hydrostatic test at operating pressure; at maximum pressure if no operating pressure has been defined.
- At most every 3 years and after major maintenance or repair: hydrostatic test at the test pressure in the manufacturing standard; at 1.5 times the maximum pressure if the standard gives no value.
Where a hydrostatic test cannot be performed, non-destructive testing methods set out in the standard or by the manufacturer may be applied, with the justification written in the report. Annex III states clearly: the fact that the process cannot be stopped is not a justification.
Today the inspection may be carried out by mechanical, metallurgical and materials, mechatronics, chemical, manufacturing and aeronautical engineers, technical teachers who graduated in machinery or metal education, and mechanical technicians and higher technicians. The person must be registered on EKİPNET (the Ministry's register of authorised inspectors), and the contract must be set up on İSG-KATİP (the Ministry's online OHS registration system) at least 1 day before the inspection. For the full equipment table, see our article on work equipment periodic inspection intervals, and for compressor tanks, see pressure vessels and compressor tanks.
What changes after 1 January 2027?
With the amendment of 23 December 2025, steam boilers were added to additional Article 2 of the regulation: their periodic inspection will be carried out by authorised persons working for equipment inspection bodies. Under provisional Article 6, this provision does not apply until 1 January 2027, and reports duly issued before that date remain valid for their term. Until the Ministry makes a new arrangement, inspection bodies accredited by TÜRKAK (the Turkish Accreditation Agency) to TS EN ISO/IEC 17020 within the relevant scope are accepted as equipment inspection bodies.
In practice, the 2027 accredited inspection requirement for steam boilers reaches you at different times depending on your inspection date:
| Last inspection date | Next inspection due by | Who will carry it out? |
|---|---|---|
| 10 March 2026 | 10 March 2027 | Equipment inspection body |
| 20 October 2026 | 20 October 2027 | Equipment inspection body |
| 15 December 2026 (by an authorised person) | 15 December 2027 | Valid for the term of the report; the next inspection by an inspection body |
What you need to do: list the latest report dates of your boilers, identify in advance a body whose accreditation scope includes steam boilers, and fit the inspection date into your production plan. Do not leave the contract with the body until the last week of your report.
Boiler operator certificate: what is required of the operator?
On what is known on site as the "boiler operator certificate", the clearest current provision is the Communiqué on Occupations Subject to the MYK Vocational Qualification Certificate Requirement of 23 March 2026 (No. 2026/1). Its annex also lists Steam Boiler Operator (Level 4), Thermal Oil Boiler Operator (Level 4) and Hot Water Boiler Operator (Level 3).
Map your operators' certification status now; for those who are not exempt, complete the examination and certification process before March 2027. For other certification requirements, see our article on the list of occupations requiring vocational training.
The 2026 base administrative fine for failing to have the required inspections carried out is 33,326 TL. Add boiler inspection dates to the OHS renewal calendar. To track your inspection schedule and link reports to your risk assessment, see our periodic inspection service; for risks specific to dye houses, see our textile and Nilüfer OSGB pages.
Frequently Asked Questions
How often is a steam boiler periodically inspected?
At least once a year unless the standards set a shorter interval. A hydrostatic test at operating pressure is carried out at every inspection; the hydrostatic test at test pressure is repeated at least every three years and after major maintenance or repair.
Will the report we obtained before 2027 become invalid?
No. Reports duly issued before 1 January 2027 remain valid for their term. When the report expires, the next inspection is carried out by an equipment inspection body.
Are central heating boilers also covered?
In Annex III, heating boilers (central heating, hot water and similar) are a separate row and are inspected once a year unless the standards set an interval. The equipment subject to the inspection body requirement from 2027 is "steam boilers"; heating boilers are not on this list.
What happens if our boiler operator has no certificate?
From 23 March 2027, a person who has no certificate and is not exempt cannot be employed as a steam boiler operator. Compliance with this rule is inspected by labour inspectors, and the sanctions in Law No. 5544 apply.
Equipment inventory and an inspection calendar under the new Annex III, with inspections carried out through our solution partners, plus report and defect follow-up.
Bursa SİSTEMER OSGB Technical Team — written from the field experience of our OHS specialists and workplace physicians. Legal information is valid as of the publication/update date; contact us for an assessment specific to your business.