Plant room maintenance checklist: what should be checked, and how often?

Who is responsible for a plant room?

Under Regulation 35 of the Gas Safety (Installation and Use) Regulations 1998, the employer or self-employed person who controls the premises must keep gas appliances and pipework in a safe condition. HSE's guidance for industrial and commercial plant adds that the gas supply should be interlocked with the ventilation of the appliance, that there should be enough ventilation to remove combustion products, and that operators should be trained in safe procedures. In practice the facilities manager organises the checks, and only a Gas Safe registered engineer with the right commercial categories works on the gas side.

Weekly checks trained site staff can do

These are look-and-record checks. None of them involves opening, adjusting or repairing gas or pressurised equipment.

• Note system pressure readings and compare them with the normal range your engineer has recorded.
• Check boiler displays, the pressurisation unit and any control or BMS panel for fault codes, lockouts or alarms, including ones that have cleared themselves.
• Look for leaks, drips, water on the floor, corrosion, scorch marks or soot, and water running from any tundish or relief valve discharge.
• Listen for unusual noise from pumps and burners, and note any smell of gas, fumes or burning.
• Check that ventilation grilles and louvres are clear inside and outside, and that nothing is stored against plant.
• Confirm that the gas emergency control valve and any emergency stop are accessible, labelled and unobstructed.
• Write the date, readings and your initials in the plant room log, and report anything abnormal.

If anyone smells gas, do not operate electrical switches, close the emergency control valve if it is safe to do so, leave the room and call the National Gas Emergency Service on 0800 111 999.

Periodic checks to add to the schedule

• Hot water temperatures: HSE's legionella guidance says hot water should be stored at 60°C or above and distributed so that it reaches at least 50°C within one minute at outlets (55°C in healthcare premises). Record temperatures as your legionella risk assessment requires.
• Alarms and detection: test gas detection, carbon monoxide alarms and BMS alarms as their manufacturers instruct.
• Housekeeping: keep the room locked and signed, lighting working, floors dry and the room free of stored materials.

What the annual engineer service should cover

A commercially qualified Gas Safe engineer should service each boiler to its manufacturer's instructions. On a typical boiler plant this includes:

• Combustion analysis on each boiler with a calibrated flue gas analyser.
• Burner, ignition and heat exchanger inspection, and cleaning where the manufacturer requires it.
• Gas pressures and gas rates checked against the manufacturer's data.
• Flame supervision, overheat and other safety devices tested.
• Flue route, joints, supports and termination checked.
• Plant room ventilation and the gas and ventilation interlock checked.
• Gas pipework and valves inspected, with a tightness test where needed (see gas tightness testing).
• Pressurisation unit, expansion vessels, pumps, valves, strainers and condensate drainage checked.
• Controls and boiler sequencing checked, especially on cascade systems.
• A written report for each boiler, listing readings, defects and recommendations.

Which rules and standards apply?

• BS 6644 covers the installation and maintenance of gas-fired hot water boilers with net rated inputs between 70 kW and 1.8 MW.
• IGEM/UP/10 covers flued gas appliances in industrial and commercial premises, including ventilation and flues.
• The Pressure Systems Safety Regulations 2000 cover steam at any pressure and pressurised hot water above 110°C, among other systems. Qualifying systems need a written scheme of examination before use. Most low temperature hot water heating does not qualify, but ask a competent person to confirm for your plant.
• HSE's L8 Approved Code of Practice and HSG274 cover the control of legionella in hot and cold water systems.

What paperwork should be kept in the plant room?

• The latest service report and gas safety record for each boiler.
• The plant room log of weekly checks.
• Schematics, operating and maintenance manuals and emergency contacts.
• Any warning notices and the record of the repair.
• The legionella risk assessment and temperature records, and a written scheme of examination where PSSR applies.

When to call an engineer straight away

Call a commercially qualified Gas Safe engineer if a boiler keeps locking out, the pressurisation unit runs often or alarms, pressure keeps falling, water discharges from a relief valve, you see soot or scorching, or a gas or CO alarm activates. Repeated lockouts are a warning, not a nuisance. Note the codes before resetting, and reset only once if the manufacturer allows.

Packaged and prefabricated plant rooms

A packaged plant room needs the same care as a built-in one. Keep the access route clear, keep its ventilation openings unobstructed and include it in the same service schedule. See our prefabricated plant rooms page.

This guide is general information, not a substitute for an on-site assessment by a Gas Safe registered engineer. If you smell gas, call 0800 111 999.