A boiler lockout log sheet for facilities teams

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A boiler lockout log sheet is a simple record that facilities teams fill in every time a commercial boiler or heater locks out: the date and time, the fault or lockout code shown on the display, the weather, what else was running, any recent work on the plant, and what was done. It gives the Gas Safe registered engineer facts instead of memories, so they can look for a pattern when they diagnose the fault. It also helps the duty holder stop resetting a boiler that keeps locking out: manufacturers' user instructions say that repeated lockouts mean the boiler should not be used until an engineer has found and put right the cause. This guide explains what a lockout is, what to record, when a reset is (and isn't) appropriate, and includes a printable log sheet.

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Commercial heating tips and advice · 19 October 2026 · Fast Commercial Boiler Help, Gas Safe 985448

What goes on a boiler lockout log sheet

What a lockout is, and why it matters

A modern commercial boiler watches its own flame, temperatures, fan and water flow. When its controls detect a problem they shut the burner down. Some shutdowns clear on their own once the condition goes away; a lockout keeps the burner off until someone presses reset. Ideal's user guide for the Evomax 2 commercial boiler, for example, sorts every fault code into one of three types: warning (W), blocking (B) or lockout (L), and its reset button resets the boiler module error "if a resettable (lockout) error is active".

A lockout is a safety device doing its job. The Evomax 2 fault list includes lockouts for flow, return and flue overheat, flame loss after restart attempts, "No flame after restarts", false flame and fan speed faults, and even a lockout for "Too many remote resets" (code 66). That last one is a useful reminder: the controls themselves treat repeated resetting as a fault.

The law points the same way. Regulation 34 of the Gas Safety (Installation and Use) Regulations 1998 (GSIUR) says the responsible person for any premises "shall not use a gas appliance or permit a gas appliance to be used if at any time he knows or has reason to suspect that it cannot be used without constituting a danger to any person." HSE's guidance for employers puts it simply: "Do not use any appliance you know or suspect is unsafe."

What manufacturers say about resetting a locked-out boiler

Whether site staff may press reset at all depends on the appliance's own user instructions, so keep them in the plant room and read them before you need them. These are examples from UK commercial manufacturers:

Ideal Evomax 2 (commercial condensing boiler). The user guide says the fault "once rectified can now be reset by pressing the reset button". For an overheat lockout it says "Press the reset button and the boiler will relight. If the fault recurs turn off the boiler and consult a suitably qualified Gas Safe registered engineer". It also says: "In cases of repeated or continuous shutdown a suitably qualified Gas Safe registered engineer ... should be called to investigate and rectify the condition causing this", and "If it is known or suspected that a fault exists on the boiler then it MUST NOT BE USED until the fault has been corrected by a suitably qualified Gas Safe registered engineer".
Hamworthy Upton (floor standing condensing boiler). The user instructions say that should a lockout occur, a code will be displayed on the screen, and: "Should a fault code appear which cannot be reset, or a fault code repeatedly occurs, contact Hamworthy Heating for assistance. Do not continue to operate or use the boiler as this may cause damage to the controls." For an overheat lockout, "the boiler must be allowed to cool down" before the reset button is pressed, and "If the problem persists, seek expert advice from your installer or Hamworthy Heating Ltd."
Powrmatic LNVx (gas-fired warm air heater). If the burners fail to light after 5 attempts, "the control box will go to lockout" and the amber lockout lamp comes on; the user instructions describe pressing the low level reset button to restart the ignition sequence, then warn: "If it is not possible to light the heater after several attempts, contact the installer or local service company." On the overheat limit thermostat, they add that "Unless the cause of the fault condition is readily obvious, for example a power cut whilst the heater was operating, a service engineer should be contacted."

The common thread: a single reset is only for the user controls the manufacturer describes, and only if your site procedure allows it. A lockout that comes back, a code that will not clear, or any sign of a gas, flue or water problem means stop, leave the boiler off and call a Gas Safe registered commercial engineer. Never open the casing, adjust the burner or gas valve, or bridge, bypass or alter a safety device or interlock.

What to record when a boiler locks out

Write it down before anyone presses reset, because a reset can clear the message from the display. On the Evomax 2, for example, the user guide says the status display's title bar alternates with "Fault", the scroll knob shows the detail of the fault, and if there are multiple faults "a list of faults will be shown". Note every code in the list, not just the first one.

Date and time the lockout was found, and when the heating was last known to be working.
Which appliance. Boiler number or module in a cascade, warm air heater or water heater, with make and model.
The exact code and message shown, the lights on the panel (for example a red LED steady or flashing), and a photo of the display if you can.
The weather. Cold snaps matter: Ideal's guide says that if the boiler's condensate pipe is blocked, condensate will build up and the boiler will make "a gurgling noise prior to locking out displaying 'Ignition Lockout'". Our guide to frost protection for commercial heating plant covers why that is more likely in freezing weather, and our guide to condensate problems on commercial condensing boilers explains the causes and what site staff can safely check.
What else was running. Was it first thing in the morning, on a timed start, during high hot water demand, or with other boilers, kitchens or process plant on? Did the building management system (BMS) or time clock change anything?
The system pressure on the plant room gauge, compared with the normal range your engineer has marked. Low water pressure is one of the faults the Evomax 2 lists. See our pressure gauge guide for how to log readings.
Anything unusual you saw, heard or smelled: noises, a smell of gas or fumes, water on the floor, scorching, or ventilation grilles blocked.
Recent work or events. A recent service or repair, a power cut, work on the gas supply, building works near the flue, or changes to controls.
What was done. Whether one reset was tried under the user instructions, by whom, and what happened next. Then who was called and the job reference.

Printable boiler lockout log sheet

Print this page and keep the sheet in the plant room with the boiler's user instructions, or copy the columns into your own log or CAFM system. One row per lockout.

Date and time	Appliance (boiler no. / model)	Code and message shown	Weather	What else was running	System pressure (bar)	Recent work or events	Reset tried? (once, per user instructions) and result	Engineer called / job ref	Initials

Give the completed sheet, and the photos, to the engineer when they arrive. Patterns such as the same code every cold morning, or lockouts only when another plant item starts, are exactly what helps find the cause.

Don't keep resetting: when to stop and call an engineer

Each reset restarts the boiler's ignition and safety checks while the cause of the lockout is still unknown. That is why the manufacturers above say to stop using the boiler and get help when a fault recurs or a code will not clear. Stop and call a Gas Safe registered commercial engineer if:

the same lockout comes back after one reset, or a code will not reset;
the boiler locks out again and again over days or weeks, even if it resets each time;
you see an overheat lockout and the cause isn't obvious;
there is any smell of gas or fumes, signs of scorching or soot, or a carbon monoxide alarm sounds;
the system pressure is outside the normal range marked on the gauge, or there is water leaking from the plant.

If you suspect a gas leak, HSE says to turn off the supply and immediately phone the National Gas Emergency Service on 0800 111 999 (for LPG, your LPG supplier), and not to turn the gas back on until the leak has been dealt with by a competent person. If in doubt, HSE says to evacuate the building and inform the police as well.

Duty holder responsibilities behind the log

Regulation 35 of GSIUR requires every employer and self-employed person to ensure that any gas appliance, installation pipework or flue installed at any place of work under their control "is maintained in a safe condition so as to prevent risk of injury to any person." HSE's guidance for employers says gas work in workplaces such as shops, restaurants, schools and hospitals must be carried out by a Gas Safe registered engineer who is qualified to do the work, that it is the employer's responsibility to check this, and that in factories and some other premises the work must be done by a competent person. For industrial and commercial plant, HSE also says to make sure "the operators are fully trained and use a safe procedure for purging, lighting up and shutting down the plant." Our guide on checking a Gas Safe engineer's commercial qualifications explains what to look for on the ID card.

Where the heating system is a pressure system covered by the Pressure Systems Safety Regulations 2000 (PSSR), HSE's brief guide INDG261 says a written scheme of examination is required for most pressure systems and that the system must be examined in accordance with it by a competent person. The same guide says to "Ensure there is a set of operating instructions for all the equipment and for the control of the whole system including emergencies", and that appropriate employees have access to them and are properly trained. A lockout log and the manufacturer's user instructions belong alongside those. See our guide to PSSR written schemes for heating plant.

Keep completed log sheets with your service reports and gas safety records. CIBSE Guide M, the CIBSE guide to maintenance engineering and management, is aimed at helping building and property operators become more aware of their responsibilities and duties, and SFG20, the maintenance specification standard created by BESA, sets out maintenance schedules that define what needs maintaining, how often and by whom. A lockout history is useful evidence when the next service is planned: see what a commercial boiler service includes and heating maintenance records insurers ask for. For a wider walk-round, use our commercial plant room safety checklist.

When your boiler is locked out

If a commercial boiler, warm air heater or water heater has locked out and won't stay running, fill in the log, leave it off, and call us on 0800 0996 007. Our Gas Safe registered engineers (Gas Safe 985448) handle emergency commercial boiler breakdowns, commercial boiler repair, warm air heater repair and plant room repair, and recurring faults can be followed up through commercial boiler servicing and planned preventive maintenance. Where oil-fired plant is fitted, our engineers who work on oil are OFTEC trained.

Safety note

Under the Gas Safety (Installation and Use) Regulations 1998, gas work must be carried out by a Gas Safe registered engineer, and we apply that rule on every site. Don't attempt DIY work on gas appliances, burners, flues or safety devices. On pressure systems, trained site staff should stick to visual and gauge checks, log the readings and report anything abnormal. Never adjust, cap, plug or test-lift a relief valve yourself.

Talk to a Gas Safe commercial engineer

Fast Commercial Boiler Help is a Gas Safe registered (985448) commercial heating business based at 4 Market Hill, Clare, Sudbury, Suffolk CO10 8NN. Our team of over 10 local engineers covers East Anglia and East London, working on commercial boilers, plant rooms, water heaters, and warm air, radiant and unit heaters. We work on commercial premises only.

Call 0800 0996 007

Call or WhatsApp 07947 578332 (a photo of the appliance data plate or the fault display helps) · Email [email protected]

Frequently asked questions

What should I record when a commercial boiler locks out?

Record the date and time, which boiler or module, the exact fault or lockout code and message (with a photo of the display if possible), the weather, what else was running, the system pressure on the gauge, any recent work or power cuts, anything unusual you saw, heard or smelled, and what was done, including whether one reset was tried under the user instructions and who was called.

Is it safe to keep resetting a boiler that has locked out?

No. Manufacturers' user instructions say repeated lockouts need an engineer. Ideal's Evomax 2 guide says that in cases of repeated or continuous shutdown a suitably qualified Gas Safe registered engineer should be called to investigate, and Hamworthy's Upton instructions say that if a fault code cannot be reset or repeatedly occurs, do not continue to operate or use the boiler. GSIUR regulation 34 also says a gas appliance must not be used if it is known or suspected to be dangerous.

Can facilities staff press the reset button on a commercial boiler?

Only if the appliance's own user instructions describe it and your site procedure allows it, and only for the user controls on the front of the boiler. Note the code first, because a reset can clear it from the display. If the lockout returns or the code will not clear, stop and call a Gas Safe registered commercial engineer. Staff should never open the casing, adjust the burner or gas valve, or bypass a safety device.

Why does the weather matter on a boiler lockout log?

Some faults are linked to cold weather. Ideal's Evomax 2 user guide says that if the boiler's condensate pipe is blocked, the boiler will make a gurgling noise before locking out and displaying 'Ignition Lockout'. Recording the weather alongside each lockout helps the engineer spot that kind of pattern.

Who is responsible for a commercial boiler that keeps locking out?

The duty holder. GSIUR regulation 35 requires employers and self-employed people to ensure gas appliances, pipework and flues at places of work under their control are maintained in a safe condition, and HSE says gas work in workplaces such as shops, schools and hospitals must be carried out by a Gas Safe registered engineer who is qualified to do the work. Where PSSR applies, the user must also have a written scheme of examination for the pressure system.

Sources and further reading