This week we will focus on the importance of using safe and suitable LPG appliances, that include Flame Failure Devices, a key safety control feature.
All appliances used in mobile catering and street food must have flame failure devices fitted. For example, water heaters, boiling rings, cookers, fryers, grills and pizza ovens etc.
Flame Failure Devices (FFDs) are also known as Flame Supervision Devices (FSDs) or thermocouples.
The Gas Safety (Installation and Use) Regulations 1998 imposes a duty on the responsible person for any premises not to use or permit the use of any unsafe appliance. It defines an unsafe/dangerous appliance as:
The relevant engineering standards, the Code of Practice (CoP) 24 Part 3 (Use of LPG for Commercial Catering Events, Street Food and Mobile Catering) states “LPG appliances shall have all burners protected by flame supervision devises”.
A thermocouple fused at both ends
A standard universal thermocouple
Interrupter universal thermocouple
MAG valve – this sits inside the gas valve body
A flame failure device (FFD) is a safety mechanism that cuts off the gas supply if a flame is extinguished, preventing a buildup of flammable gas. It works by detecting the presence or absence of a flame, typically using a thermocouple or other flame sensing technology.
When the flame is present, the thermocouple produces a s mall electrical signal that is sent down to a magnet that is housed within the gas valve body. When the charge is sufficient the magnet remains closed allowing gas to pass through the control valve to the burner (where the probe sits) which keeps the valve open, supplying the appliance with gas.
When the flame goes out (e.g. it is accidentally blown out), the thermocouple cools down and it stops sending a signal, which causes the magnet within the gas valve body to lose its magnetism, automatically closing the valve, shutting off the supply of gas to the unlit burners.
It provides a crucial safety feature. This is especially important in open-air settings where wind or adverse weather conditions could cause a flame to go out.
Not all LPG appliances are suitable for commercial catering operations and will not have FFDs fitted as standard by the manufacturer. This is because they are instead designed for low level, infrequent domestic use. For example, domestic camping stoves have no flame failure devises.
Some low cost imported products are being sold into the UK without conformity standards (CE, UKCA/UKNI) and without FFDs fitted to the burners.
Always check before you buy. Confirm with the supplier or manufacturer that the appliance is fitted with FFDs to each of the burners and the appliance has a conformity standard (e.g. CE, UKNA, UKNI) and therefore meets the required safety and environmental standards. Avoid being tempted to purchase appliances where this cannot be verified.
Some appliance manufacturers’ may have retro fitted thermocouple kits available to upgrade the appliances for use in a commercial environment.
If in doubt ask a Gas Safe LPG engineer to check the suitability of an appliance for you. During a gas safety service, a gas engineer must check if the FFDs are working correctly and should be highlighting when an appliance is not suitable for use. They should not be installing appliances without FFDs for use in a commercial catering set up.
The following are examples of unsuitable appliances which should not be used in a commercial setting.
A brand new (2025) Three Burner Fryer – manufactured in China and unsuitable for the UK market. It has no CE standard, no temperature probes or safety devices and does not have FFDs fitted to the burners.
20m Paella Burner – suitable for domestic use only. No FFDs fitted to the burner.
A replica of a Foker burner without a FFD. The most common example of an unsuitable appliance for commercial use.
Some commercial grade BBQ’s may not require a flame failure device fitted per burner control providing that the burner is housed within its own compartment and has non- confusing controls (reference BS EN 498:2012).
Although outside the scope and recommendations set out in Liquid Gas UK Code of Practice 24 Part 3, appliances such as these are to be risk assessed and certified as safe to use following the guidance in BS EN 498:2012 and the Manufactures’ instructions.
Examples include: – Cinders BBQs are commercial grade appliances specifically designed for high output commercial catering and do not have FFDs. They are suitable for use in the open air following a suitable risk assessment.
Note: BBQs that have a carryover burner without flame failure devices are NOT suitable for commercial catering. These types of appliances will have 4-5 burners fitted in row or on bar at the back of the appliance.
The primary purpose of the carry-over bar is to continuously attempt to relight the burners that extinguish, for a small period allowing unburnt gas to escape into atmosphere, the burners relight adventurously through a process called explosive relighting.
Some manufacturers will have flame failure retro fit kits available. These must only be provided by the manufacturer of the intended appliance that is to be upgraded and fitted by a suitably qualified and competent Gas Safe Registered engineer. It is illegal to retro fit or amend an appliance outside the appliances CE standard so permission from the manufacturer must be sought.
For more useful advice and information check out all the previous features “LPG Safety in the Spotlight” on the NCASS Gas Hub.
Check out our free guides on the NCASS Gas Hub Free Resources area.
Also remember to refer to the NCASS Gas Safety Checklist which is included within the NCASS SMS. The checklist will allow you to comprehensively assess the safety of your LPG set up and details the open and close procedures.
Are you looking for a Gas Safe Registered LPG engineer? Find your nearest Gas Engineer Partner (GEP) – tried and trusted engineers competent in LPG. Log into the members only gas engineer page.
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