Warehouse heater servicing: why every boiler and space heater needs a yearly check
Commercial engineers covering Suffolk, Essex and Cambridgeshire
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Most warehouses and factories heat with a mix of plant. There is often a boiler serving offices and welfare areas, and then warm air heaters, radiant tube or plaque heaters, or unit heaters over the working floor. Every one of those appliances burns fuel close to people and stock, and every one needs a yearly service by a competent engineer. This guide covers why, what the law and manufacturers say, and what your site team can safely do between visits.
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What the law expects from the duty holder
For most commercial premises the starting point is the Gas Safety (Installation and Use) Regulations 1998 (GSIUR). Regulation 35 requires every employer or self-employed person to ensure that "any gas appliance, installation pipework or flue installed at any place of work under his control is maintained in a safe condition so as to prevent risk of injury to any person."
The regulation does not set a fixed service interval. HSE's guidance for employers says gas appliances should be maintained by a competent person "in line with manufacturers' instructions and appropriate standards", and that in workplaces such as shops, restaurants, schools and hospitals, gas work must be done by a Gas Safe registered engineer who is qualified for that work. HSE's Approved Code of Practice L56 explains how the regulations apply in practice.
One point factory managers often miss: regulation 2(4) takes factories (as defined by the Factories Act 1961) and agricultural premises out of most of GSIUR. That is not a loophole. The general duties of the Health and Safety at Work etc Act 1974 still apply, and HSE's catering guidance notes that where GSIUR does not apply, employers still need competent people for gas work, and that Gas Safe registration is "the clearest way of demonstrating competence".
What the manufacturers say
Manufacturers' instructions are where the yearly interval usually comes from. Two examples from warehouse and factory heaters:
- Warm air heaters: Powrmatic's LNVx user, installation and servicing manual says the heater must be serviced annually by a qualified person to keep it running efficiently, reliably and safely. The same manual says free access must be kept around the heater, its air supply must not be restricted, and combustible materials must not be stored next to it.
- Radiant tube heaters: the AmbiRad Vision installation manual says the heaters "should be serviced annually by a competent person to ensure safe and efficient operation", and that "in exceptional dusty or polluted conditions more frequent servicing may be required".
Always go by the manual for the model on your site. If the manual is missing, your engineer can usually get a copy from the manufacturer.
Why each type of heater needs its yearly check
| Appliance | What a service looks at (typical) |
|---|---|
| Commercial boilers (single or cascade) | Burner and combustion performance, heat exchanger condition, flue and chimney, safety and flame-supervision controls, condensate disposal on condensing models, and system pressure. |
| Warm air heaters | Heat exchanger integrity, burner, fans and belts, overheat limit controls, filters, flue, and clearances to stock and racking. |
| Radiant tube heaters | Burner, tubes and brackets, reflectors (dust cuts useful radiant output), the fan and its air-proving device, and the flue or ventilation arrangement. |
| Radiant plaque (luminous) heaters | Plaque condition, burner and ignition, and ventilation. These heaters are generally flueless, so they rely on the building's ventilation arrangements. |
| Fan and unit heaters | On gas-fired units, the same combustion, flue and safety checks as a warm air heater. On units fed from the boiler, the coil, fan, valves and controls. |
The installation and maintenance of these appliances is covered by recognised standards, including IGEM/UP/10 for flued gas appliances in industrial and commercial premises (it lists hot water boilers, warm air heaters and radiant heaters and covers servicing and maintenance) and BS 6896 for gas-fired overhead radiant heaters. A competent commercial engineer works to these, not to a domestic checklist.
Why a skipped year costs more than the service
Warehouse and factory air carries dust, fibres and sometimes process fumes. That builds up on burners, fans, filters and reflectors, which is why the AmbiRad manual allows for more frequent servicing in dirty conditions. Neglect shows up as lockouts on the first cold morning, uneven heat across the floor, and burners running dirty.
There is a people cost too. Regulation 7 of the Workplace (Health, Safety and Welfare) Regulations 1992 requires a reasonable temperature in indoor workplaces. HSE's Approved Code of Practice L24 gives a guideline minimum of 16°C, or 13°C where work involves rigorous physical effort. A heater row that fails in January makes that hard to meet.
What trained site staff can safely do between services
The checks below are visual checks only. None of them involves opening, adjusting or repairing gas equipment. That work is for a Gas Safe registered commercial engineer only.
- Keep the manufacturer's clearances around heaters. Don't stack stock, pallets or packaging close to them or across flue terminals and air inlets.
- Keep ventilation openings clear, especially where flueless plaque heaters are fitted.
- Read the boiler pressure gauge and compare it with the normal range your engineer has recorded. Log the reading and report anything abnormal.
- Note any heater that locks out, shows a fault code, smells, is noisy, or shows soot or scorching. Log the date, the unit and what you saw. A lockout is a safety device doing its job, so don't keep resetting it. Report it to a Gas Safe registered engineer.
- Keep the service reports and gas safety records together so they are easy to find for insurers, landlords and auditors.
- If you smell gas, call the National Gas Emergency Service on 0800 111 999, then follow your site emergency procedure.
Plan it as one visit, before the cold
The easiest approach is to group every appliance on site into one planned visit before the heating season: boilers, warm air, radiant and unit heaters together. Facilities teams often use BESA's SFG20 maintenance specification or CIBSE Guide M to structure these schedules. If you would like an engineer to walk the site and list what needs servicing, see our commercial boiler servicing and planned preventative maintenance pages, or our industrial and warehouse heating page. For warm air, radiant or unit heaters that have already failed, see warm air and radiant heater repair, or go to emergency commercial boiler help.
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 or WhatsApp 07947 578332 (a photo of the appliance data plate or the fault display helps) · Email info@fastcommercialboiler.help
Getting a warehouse ready for service day
On a busy warehouse floor, the heater service itself is rarely what takes the time. Access is. Most warm air and radiant tube heaters hang several metres up, over racking, picking aisles or loading bays, and the engineer needs safe access to every one. Planning these points before the visit keeps it to one day rather than two:
- Access equipment. Agree in advance whether a mobile elevating work platform (a scissor lift or cherry picker) or a fixed access route is needed, who supplies it, and whether the floor can take it. Many sites already hire one for other high-level work and can share the booking.
- Clear zones. Each heater needs a working area below it kept clear of forklift and pedestrian traffic while the engineer is up. Plan which aisles or bays can be closed and when.
- Shift timing. Heaters must be cool and isolated before work starts. On sites that run around the clock, service one zone at a time so the rest of the floor stays heated.
- Site rules. Tell us about permits to work, inductions, hi-vis and PPE rules, and any food safety or clean-area procedures before the day, so the engineer is not stopped at the gate.
- A heater list. Number each heater on a simple floor plan. The service report then records findings against that number, which makes repeat problems easy to spot next year.
Signs a heater should not wait for its next service
A yearly service is the minimum. Report any of these straight away, and stop using the heater if the manufacturer's instructions or your engineer say so:
| What you notice | What it can point to |
|---|---|
| Soot, scorching or discolouration on a heater casing, reflector or nearby surface | Poor combustion or a flue or exhaust problem. Treat it as urgent. |
| Repeated lockouts, especially on the first cold start | Ignition or flame sensing faults, or an air-proving device or fan problem on radiant tubes |
| A warm air heater that runs briefly then stops | Overheat limit tripping, often from blocked filters, a slipping belt or a failing fan |
| New noises: rumbling, whistling, rattling fans | Burner, fan bearing or exhaust fan wear |
| Unusual smells or staff complaining of headaches near a heater | Possible combustion products in the space. Isolate the heater, ventilate and call a Gas Safe engineer. |
| Cold zones where the floor used to be warm | Failed burner on one tube run, dirty reflectors, or controls and zoning faults |
Our guides to radiant tube heater maintenance and warm air heater heat exchanger inspection explain what the engineer checks on each type in more detail. If the boiler serving the offices and welfare areas is also due, see what a commercial boiler service includes, so both can be done on the same visit.
Frequently asked questions
Is annual servicing a legal requirement for warehouse heaters?
The law requires gas appliances, pipework and flues at a place of work to be maintained in a safe condition (GSIUR regulation 35, or the general duties of the Health and Safety at Work etc Act 1974 where GSIUR does not apply). The regulation does not print an interval. HSE says to follow the manufacturer's instructions, and manufacturers of warm air and radiant heaters typically specify an annual service.
Who can service gas-fired radiant tube, plaque and warm air heaters?
A Gas Safe registered engineer who holds the right non-domestic (commercial) qualifications for that type of appliance. HSE says you can check an engineer's registration and qualifications through the Gas Safe Register's Check an Engineer service using the licence number on their ID card.
Our factory is very dusty. Is once a year enough?
Not always. The AmbiRad Vision manual, for example, says more frequent servicing may be needed in exceptionally dusty or polluted conditions. Your engineer can recommend an interval based on the site and the manufacturer's instructions.
Can our maintenance staff clean heater reflectors or burners?
Not the burners or any part of the gas system. That is gas work and must be done by a competent Gas Safe registered engineer. Reflectors are high up on a live gas appliance, so leave them to the engineer at the service too. Trained site staff can keep clearances, keep vents clear, and log and report faults.
What should we keep on file after a service?
Keep the engineer's service report and any gas safety record for each appliance, noting defects found and work done. Keeping them makes it easy to show that each appliance has been maintained, and insurers and landlords often ask to see them.
How long does a warehouse heater service take?
It depends on the number of heaters, the type and, above all, access. With a platform booked and the floor below cleared, an engineer can typically work through several heaters in a day. Sites with many heaters over live racking may need to be split into zones over more than one visit. Send us the heater list and a rough floor plan and we will give you a realistic estimate.
Who provides the access platform for high-level heaters?
That is agreed before the visit. Some sites already have a scissor lift or cherry picker on hire, others ask us to arrange one. Either way it needs to be suitable for the floor, operated by a trained person, and booked for the same day as the service.
Can warehouse heaters be serviced in summer?
Yes, and it is often the best time. Heaters are not needed, so they can be isolated without affecting staff, and any parts found to be worn can be ordered and fitted before the heating season starts.
Do you service the office boiler and water heater on the same visit?
Yes. Most warehouses have a boiler or water heater for the offices, toilets and canteen as well as the heaters over the floor. Servicing everything in one planned visit keeps the records together and saves a second call-out charge.
Sources and further reading
- Gas Safety (Installation and Use) Regulations 1998, regulation 35 (legislation.gov.uk)
- GSIUR 1998, regulation 2: interpretation and application (legislation.gov.uk)
- HSE: Gas safety for employers
- HSE L56: Safety in the installation and use of gas systems and appliances (ACOP)
- HSE CAIS23: Gas safety in catering and hospitality
- HSE: Check an engineer, are they Gas Safe registered?
- Powrmatic LNVx warm air heater user, installation and servicing manual
- AmbiRad Vision VS radiant tube heater installation manual (distributor-hosted copy)
- IGEM/UP/10 Edition 4: Installation of flued gas appliances in industrial and commercial premises
- BS 6896:2011 Installation and maintenance of gas-fired overhead radiant heaters (BSI)
- Workplace (Health, Safety and Welfare) Regulations 1992, regulation 7: temperature
- HSE L24: Workplace health, safety and welfare ACOP
- BESA SFG20: What is SFG20?
- CIBSE Guide M: Maintenance engineering and management
Call or WhatsApp 07947 578332 · info@fastcommercialboiler.help