Radiant tube heater repairs and maintenance in warehouses
Commercial engineers covering Suffolk, Essex and Cambridgeshire
Winter gas safety: smell gas? Call National Gas Emergency on 0800 111 999. For commercial boiler breakdowns call 0800 0996 007.
Radiant tube heaters hang high above warehouse aisles and factory floors. They warm people and stock by radiation rather than by heating all the air, so they suit high-bay buildings. They also collect dust on tubes and reflectors, and they need clear space below and beside them. This guide covers radiant tube heater maintenance for commercial sites: why dusty reflectors cut useful heat, how manufacturer clearances protect stock and racking, how often dirty sites need a service, and where BS 6896 and IGEM/UP/10 fit in.
Need a radiant tube heater repair now?
If a radiant tube heater has stopped, keeps locking out or fires without warming the floor, switch it off at its local isolator after one failed reset, note the fault light or code, and keep people and stock clear of the area under it. Then call 0800 0996 007. A Gas Safe registered engineer (registration 985448) will diagnose the fault with a combustion analyser and proper access equipment. The repair visit steps and common parts below explain what usually happens, and the fault table links symptoms to causes.
A team of over 10 local engineers to call on · Gas Safe 985448 · Call 0800 0996 007 · WhatsApp 07947 578332
What a radiant tube heater is (and what the standards cover)
A typical gas-fired radiant tube heater has a burner, radiant tubes, overhead reflectors and a fan. The burner fires into the tube; the hot tube radiates heat downward; the reflector directs that radiation toward the working floor. AmbiRad's Vision VS installation and servicing manual (a common warehouse range, hosted by distributors) describes stainless-steel or aluminised reflectors and induced or forced burners, and it says AmbiRad equipment must be installed and maintained in accordance with relevant Standards and Codes of Practice, including BS 6896 for industrial and commercial radiant heaters, by a competent person.
BS 6896 specifies installation and maintenance requirements for gas-fired overhead radiant heaters used for environmental heating of premises other than domestic dwellings. IGEM/UP/10 Edition 4 covers flued gas appliances in industrial and commercial premises, including radiant heaters, and it includes commissioning, handover, servicing and maintenance. It notes that it aligns requirements with BS 6896 (among other Standards). Flueless radiant heaters sit outside the flued scope of IGEM/UP/10 and are pointed at BS 6896 instead. On every site, gas work must be done by a Gas Safe registered engineer under the Gas Safety (Installation and Use) Regulations 1998.
Why dust on reflectors and tubes cuts useful heat
Warehouse and factory air carries dust, fibres and sometimes process fumes. That settles on the underside of the reflectors and on the outside of the radiant tubes. The AmbiRad Vision service instructions say the condition of the reflectors should be noted at service, and that cleaning them with a mild detergent "can significantly improve the efficiency of the appliance." The same manual's tube-servicing steps include brushing dust from the exterior of the tubes and, where needed, cleaning the tube interiors. Dust on the combustion fan impeller and scroll is also removed with a soft brush during the service.
Dusty reflectors do not usually look dramatic from the floor, but they reduce how much radiant heat reaches the working zone. The result is cold spots under a heater row that still appears to be firing, longer warm-up times, and more complaints from staff. That is why manufacturer instructions treat reflector condition as part of the service, not as a cosmetic wipe.
Clearances to stock, racking and combustibles
Overhead radiant heaters emit intense heat below and around the tubes. The AmbiRad Vision manual gives minimum clearances to combustible materials and states that those minimum distances "MUST be adhered to at all times." For its U-tube models, the published table includes (by size band) clearances such as about 1,500–2,100 mm below the tubes, 900–1,100 mm to the sides, and 180 mm above the reflector (280 mm on aluminised-reflector variants). Linear models have their own table, with below-tube figures in the same order and side clearances often around 750 mm. Always use the table for the exact model on your site; do not guess from another heater.
In practice, the clearance below the tubes is the one warehouse teams breach most often. Pallet racking, stacked packaging, hanging wraps and temporary stock can creep into the radiant zone. That is a fire and damage risk, and it can also affect how the heater performs. Trained site staff should keep the published clearances clear of stock and combustibles, and report any heater whose outlet or flue arrangement looks obstructed. Changing brackets, tubes or clearance arrangements is engineer work.
How often should radiant tube heaters be serviced?
Always follow the manufacturer's instructions for the heaters on your site. The AmbiRad Vision manual is clear on frequency:
- The appliances "should be serviced annually by a competent person to ensure safe and efficient operation."
- "In exceptional dusty or polluted conditions more frequent servicing may be required."
- The user section repeats that annual service is recommended in normal working conditions, with more frequent visits where the site is exceptionally dusty or polluted.
Dusty packing halls, woodworking shops, recycling sheds and sites with process fumes are typical candidates for a shorter interval. Your engineer can set that from the manufacturer's instructions and what they find on the first visits. The same Vision manual also says ducted combustion air must be used where there is airborne dust or a polluted atmosphere (for example chlorinated vapours), so dirty-site problems are not only about reflector cleaning.
For most commercial premises the duty holder still has to keep gas appliances, installation pipework and flues in a safe condition under GSIUR regulation 35 (or under the general duties of the Health and Safety at Work etc Act 1974 where GSIUR does not apply to a factory). HSE's guidance for employers is to maintain appliances in line with manufacturers' instructions and appropriate Standards, using a Gas Safe registered engineer who is qualified for the work.
What a competent service typically covers
Using the AmbiRad Vision servicing section as a published commercial example (your model may differ), a yearly visit typically includes:
| Area | What the engineer checks or cleans (Vision example) |
|---|---|
| Burner and injector | Burner removal after isolating gas and electricity; inspect and clean or replace a contaminated injector; check the burner head and ignitor assembly. |
| Combustion fan | Inspect the impeller, remove dust from the impeller and fan scroll, and check free rotation. |
| Radiant tubes | Brush dust from tube exteriors; inspect visually; clean interiors and turbulators if needed. |
| Reflectors | Note condition; clean with mild detergent where necessary to restore efficiency. |
| Flue | Inspect and clean if necessary, in line with the regulations that apply to the installation. |
| Re-commissioning | Re-commission the heater after the service as set out in the manufacturer's instructions. |
That is gas appliance work. It is not a job for caretakers or general maintenance staff, even when the heater is cold.
What trained site staff can safely do between services
The AmbiRad Vision user section describes limited routine maintenance between service intervals: after ensuring the heater is cold and the mains electricity is isolated, cleaning reflectors with a soft cloth and a mild detergent (non-solvent cleaners only), and additional dust removal from tubes, burner and heat exchanger. On a warehouse heater that still leaves a working-at-height problem. Reflectors sit high above aisles on a gas appliance. For most sites the safer rule is the one we use across this series: leave reflector and tube cleaning to the Gas Safe registered engineer at the planned service, and keep site staff on the floor-level checks below.
- Keep the manufacturer's clearances to stock, racking and combustibles. Do not store packaging or pallets in the radiant zone under or beside the tubes.
- Keep flue terminals and any ducted air intakes clear. Report damage, corrosion or a terminal that looks blocked.
- Note heaters that lock out, smell, show soot or scorching, or leave a cold patch underneath while neighbouring units feel normal. Log the date, unit identity and what you saw. Do not keep resetting a lockout.
- If lockout happens three times in a row, the Vision user instructions say to isolate gas and electricity and call a service engineer. Follow that approach on any make: stop resetting and get a competent engineer.
- Keep service reports and gas safety records for each heater where insurers, landlords or auditors can find them.
- If you smell gas, call the National Gas Emergency Service on 0800 111 999, then follow your site emergency procedure.
Radiant tube heater faults and repairs
When a radiant tube heater fails, the symptom usually points to one part of the heater. The list below is a guide to what an engineer will look at first. It is not a list of jobs for site staff: all of it is gas appliance work at height.
| What you see | Common causes the engineer checks |
|---|---|
| Heater goes to lockout, often after a few attempts to light | Ignition electrode worn or out of position, a dirty or failed flame sensing probe, low gas pressure, or a faulty gas valve. |
| Fan runs but the burner never lights | The air pressure switch is not proving, which can be caused by a blocked flue or air intake, a split or blocked sensing tube, or a worn fan. |
| Heater fires but the floor under it stays cold | Dust on the reflectors or tubes, internal tube fouling, a turbulator that has moved or failed, or the heater firing at a lower setting than it should. |
| Soot at the tube ends or flue, or a smell when the heater runs | Poor combustion. The heater should be switched off and checked, because it needs a combustion test, not just cleaning. |
| Tubes sagging, bowed or badly discoloured | Overheating, failed hangers or supports, or tubes at the end of their life. Distorted tubes are normally replaced rather than straightened. |
| Whole zones too hot or too cold | Controls rather than the heater: a timer, zone controller or black bulb sensor that is faulty, badly placed or set wrongly. |
Fouled tubes and cleaning
Dust on the outside of the tubes and reflectors is mostly about lost output, and it is cleared at the service. Deposits inside the tubes are different. They usually come from combustion that is not right, or from a dusty or contaminated air supply, so cleaning the tube alone does not fix the cause. See radiant tube cleaning and internal fouling below. The engineer should check the burner, gas pressure and combustion, and look at whether the heater needs ducted combustion air on a dirty site.
Repair or replace?
A heater with a good burner and sound tubes is usually worth repairing. Replacement starts to make sense when tubes are distorted or corroded along their length, parts for an older model are no longer available, or several heaters in one building are failing in the same way. We will tell you which applies, with the reason, before any work goes ahead.
Help us arrive ready
When you call 0800 0996 007, tell us the make and model if you know it, how many heaters are affected, what the lockout or fault light shows, and roughly how high the heaters are mounted. Mounting height matters because most radiant heaters need a scissor lift or other access equipment, and the floor underneath must be clear of stock and traffic while the engineer works. Photos of the heater label and the controls by WhatsApp on 07947 578332 help us bring the right parts.
Radiant tube cleaning and internal fouling
Two different jobs are often both called radiant tube cleaning. Dusting the reflectors and the outside of the tube restores lost output and is part of every service. Cleaning the inside of the tube is a repair-type job: deposits inside the tube mean something has gone wrong, and the cause has to be found as well as the dirt removed.
| External cleaning | Internal cleaning | |
|---|---|---|
| What it removes | Dust and debris on reflectors, tube outer surface and burner housing | Soot, scale or dust deposits inside the tube and on the turbulator |
| Why it builds up | Normal for warehouses, workshops and process areas with airborne dust | Poor combustion, incorrect gas pressure, a dusty or contaminated air supply, or a long time without a service |
| Typical signs | Warm-up is slow and the floor under the heater feels cooler than it used to | Repeated lockouts, the air pressure switch not proving, soot at the tube end or flue, hot spots or discoloured tube sections |
| Who does it | Done at the service by the engineer; trained staff only where the manufacturer allows and the heater is isolated | Always a competent engineer, with the heater isolated and cool and the tube or flue path reassembled and tested afterwards |
What a proper internal clean involves
With the heater isolated and cool and the area underneath cleared, the engineer follows the manufacturer's instructions for that model. That normally means opening the tube at the end cap or tail section, removing the turbulator, brushing or vacuuming the bore, and checking the turbulator, gaskets and seals before refitting. The heater is then fired and a combustion check is taken, because a clean tube only proves the symptom has gone, not that the burner is set up correctly.
Find the cause, not just the dirt
If a tube has fouled inside, the engineer should also check the burner, the gas pressure at the heater, the condition of the burner head and the combustion air supply. On very dusty sites, heaters that draw air from inside the building can foul repeatedly, and the fix may be a ducted combustion air supply or a shorter service interval. Ask for the tube condition and any cause found to be written on the service report, so the next visit can compare.
Fouling across several heaters in the same building usually points to a site-wide cause, such as dust from a process or a gas supply problem, rather than a fault with one heater. Our yearly warehouse heater servicing guide covers how service intervals are set, and warm air and radiant heater repair explains how we handle callouts.
What happens on a radiant tube heater repair visit
- Make the area safe. The floor under the heater is cleared and coned off, and the access equipment (usually a scissor lift or mobile tower) is set up. Racking aisles may need closing for the time the engineer is at height.
- Read the fault. The engineer notes the lockout light or controller code, checks the control panel, zone timer and black bulb sensor, and confirms the heater is actually being asked to run before opening anything.
- Watch a start attempt. A radiant tube heater has a set start-up order: the fan or exhauster runs, the air pressure switch proves, then ignition and gas valve open and the flame is detected. Where that order stops tells the engineer which part to test.
- Test the suspect part. Gas inlet and burner pressures are measured, the flame signal is checked, the air pressure switch and its sensing tubes are tested, and electrical supplies are checked. Parts are tested before they are replaced, rather than swapped on a guess.
- Repair and recommission. After a part is fitted, the heater is run through several full cycles, combustion is checked with a flue gas analyser where the heater design allows it, and the flue and clearances below are looked at again.
- Write it up. You receive a record of what was found, what was fitted and anything else that needs attention. A heater found to be unsafe is dealt with under the industry Unsafe Situations Procedure and explained to you in writing.
Parts commonly replaced on radiant tube heaters
- Ignition electrode and flame sensing probe: wear and contamination here are among the most frequent causes of lockout on dusty sites.
- Air pressure switch and sensing tubes: a perished or blocked tube can stop the heater proving air flow even when the fan is fine.
- Fan or exhauster: worn bearings show up as noise or slow run-up before the fan fails outright.
- Gas valve and burner control box: replaced when testing shows they are not opening or not controlling the sequence correctly.
- Burner head and gaskets: cleaned or replaced if combustion readings are poor or there are signs of overheating.
- Tubes, couplers, turbulators and end caps: replaced when tubes are distorted, corroded or leaking at joints, or a turbulator has failed.
- Reflectors, hangers and supports: damaged reflectors waste heat onto the roof, and failed hangers let tubes sag.
- Controls: zone controllers, timers and black bulb sensors, which measure radiant heat at working height rather than air temperature.
Parts should match the manufacturer's specification for the model. Many warehouses have heaters of different ages and makes, so a photo of each heater's data plate helps us check parts availability before the visit.
Linear, U-tube and multi-burner systems: what changes for repairs
Linear and U-tube heaters have one burner per heater, so a fault normally affects one heater and the rest of the building keeps its heat. U-tube heaters have the burner and exhaust at the same end, which can make access simpler. Continuous or multi-burner systems run several burners along a long tube with a shared exhaust fan at the end. On those, a fan or vacuum fault can take out a whole run, so the fan and its proving switch are the first things to check when a complete zone goes cold at once. Whichever type you have, gas work on it is carried out by a Gas Safe registered engineer under the Gas Safety (Installation and Use) Regulations 1998.
If you also have warm air heaters or boilers serving offices and welfare areas, our warm air and radiant heater repair page covers both heater types. Our warm air heater heat exchanger inspection guide covers the other common warehouse heater, and for boiler lockouts the lockout log sheet for facilities teams works for heater faults too. Sites with several heater types often move to a planned maintenance plan so every heater is seen before winter.
Plan radiant heaters with the rest of the warehouse plant
The easiest approach is to put radiant tubes on the same planned visit as warm air heaters, unit heaters and any boiler plant serving offices or welfare, before the cold season. That matches the yearly interval most manufacturers publish, and it gives the engineer one walk of the high-bay floor to catch clearance problems as well as burner faults. For a wider look at yearly warehouse heater servicing, see our guide to warehouse heater servicing and yearly checks. For heaters that have already failed, see warm air and radiant heater repair, our space heater services, or industrial and warehouse heating. If plant is down now, 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 [email protected]
Frequently asked questions
How often should radiant tube heaters be serviced in a warehouse?
Follow the manufacturer's instructions for the heaters on your site. As a published commercial example, the AmbiRad Vision manual says the appliances should be serviced annually by a competent person, and that in exceptional dusty or polluted conditions more frequent servicing may be required. Your engineer can set the interval from the manual and site conditions.
Why do dusty reflectors matter on radiant tube heaters?
Radiant tube heaters rely on the tubes and overhead reflectors to direct heat onto the working floor. The AmbiRad Vision service instructions say reflector condition should be noted and that cleaning reflectors with a mild detergent can significantly improve the efficiency of the appliance. Dusty reflectors are a common reason a heater still fires but the aisle underneath feels cold.
What clearances do we need under radiant tube heaters?
Use the clearance-to-combustibles table in the manufacturer's instructions for your exact model. AmbiRad's Vision manual says those minimum distances must be adhered to at all times. Its U-tube table, for example, shows about 1,500–2,100 mm below the tubes depending on size, plus side and above-reflector clearances. Keep stock and racking out of that zone and ask your engineer if you are unsure.
Can our warehouse staff clean the reflectors between services?
The AmbiRad Vision user section allows limited reflector cleaning only when the heater is cold and the mains electricity is isolated, using a soft cloth and a mild detergent. On overhead warehouse heaters that still means working at height on a gas appliance. For most sites it is safer to leave reflector and tube cleaning to a Gas Safe registered commercial engineer at the planned service. Site staff should keep clearances clear, log faults and report lockouts rather than climbing to clean heaters.
Which standards cover radiant tube heater installation and maintenance?
BS 6896 specifies installation and maintenance of gas-fired overhead radiant heaters for industrial and commercial heating (not domestic dwellings). IGEM/UP/10 covers flued gas appliances in industrial and commercial premises, including radiant heaters, and includes servicing and maintenance; it aligns with BS 6896. Gas work must be carried out by a Gas Safe registered engineer under the Gas Safety (Installation and Use) Regulations 1998.
Why does my radiant tube heater keep locking out?
Repeated lockout usually means the heater is not completing its start-up order: the air pressure switch not proving, the ignition electrode or flame probe not working properly, or low gas pressure. Note the fault light, reset no more than once, and call a Gas Safe registered engineer if it locks out again.
Can one radiant tube heater be repaired while the others keep running?
Usually yes. Linear and U-tube heaters each have their own burner, so one can be isolated and repaired while the rest keep heating. On a multi-burner system with a shared exhaust fan, the whole run may need to be off for some repairs.
Is it worth repairing an old radiant tube heater?
A heater with sound tubes and a good burner is usually worth repairing. Replacement is worth considering when tubes are distorted or corroded along their length, parts are no longer available, or several heaters are failing the same way. We explain which applies before any work goes ahead.
Do you repair radiant tube heaters in homes or domestic garages?
No. Fast Commercial Boiler Help works on commercial premises only, such as warehouses, factories, workshops, depots and sports or leisure buildings.
How do you clean the inside of a radiant tube heater?
It is engineer work, done with the heater isolated and cool. Where the manufacturer's instructions allow, the engineer removes the end cap or tail section and the turbulator, brushes or vacuums the inside of the tube, checks the turbulator and seals, refits them and then runs a combustion check. Staff should never open the tube or flue path themselves.
Is radiant tube fouling dangerous?
It can be. Heavy internal deposits restrict the flue path, so the air pressure switch may fail to prove, the heater can lock out or run with poor combustion, and the tube can overheat in places. A heater with soot at the tube end, a smell or sagging tubes should be switched off and checked by a Gas Safe registered engineer.
How often do radiant tubes need cleaning inside?
There is no single interval. Many tubes on clean sites need little more than an inspection at the annual service, while heaters on dusty sites, or ones that have run with poor combustion, may need internal cleaning more often. The engineer should record the condition of the tube each year so you can see whether fouling is building up.
Sources and further reading
- AmbiRad Vision VS radiant tube heater installation manual (distributor-hosted copy)
- BS 6896:2011 Installation and maintenance of gas-fired overhead radiant heaters (BSI)
- IGEM/UP/10 Edition 4: Installation of flued gas appliances in industrial and commercial premises
- Gas Safety (Installation and Use) Regulations 1998, regulation 35 (legislation.gov.uk)
- HSE: Gas safety for employers
Call or WhatsApp 07947 578332 · [email protected]