Gas Interlock System for Commercial Kitchens: What It Is and Do You Need One?
Gas Interlock System for Commercial Kitchens: What It Is and Do You Need One?
A gas interlock system for commercial kitchens is a legal safety requirement for most UK premises operating gas appliances under mechanical ventilation. If you are planning a new kitchen fit-out or refurbishment, this guide explains how the system works, what UK regulations require, and whether your kitchen needs one.
What Is a Gas Interlock System?
A gas interlock system is a safety device that automatically cuts the gas supply to kitchen appliances when the extraction ventilation stops or fails.
The system links your gas supply directly to your kitchen extraction and ventilation. When extraction is running, gas flows to your appliances. When extraction stops or fails, the interlock shuts the gas supply off automatically.
This prevents a dangerous build-up of combustion by-products — carbon monoxide, nitrogen dioxide, and heat — that accumulate whenever gas appliances run without active ventilation. The system also cuts the gas when staff switch extraction off at the end of service, so no appliance can run unattended without ventilation.
How It Works
When a chef lights a gas range, the extraction fan is already running. The interlock’s airflow sensor detects that air is moving through the duct and sends a signal to the control panel. The control panel confirms ventilation is active and holds the gas solenoid valve open. If the fan fails, a duct blockage reduces airflow, or staff switch the extraction off, the sensor no longer detects sufficient airflow. The interlock controller triggers and the solenoid valve closes, cutting gas to every appliance on that circuit.
The Four Key Components
Control panel (also called the interlock controller): wall-mounted near the extraction switch, it monitors all connected sensors and valves and displays the system status through indicator lights.
Gas solenoid valve: fitted to the gas supply line, it opens when ventilation is confirmed running and closes the moment airflow drops or a fault is detected.
Airflow sensor (also referred to as a ventilation proving device): mounted inside the extraction duct, it measures whether air is physically moving. If airflow falls below the set threshold, it signals the panel to close the valve.
Interlock wiring: the electrical connection between the fan, sensor, panel, and valve that ties the whole system together.
Some installations also integrate a carbon monoxide detector, which provides a separate alarm layer if CO levels rise regardless of ventilation status.
Is a Gas Interlock System a Legal Requirement in the UK?
Yes — under IGEM/UP/19 and BS 6173, a gas interlock system is a legal requirement for all new commercial kitchen installations and significant refurbishments in the UK.
Two standards set the specific obligations.
IGEM/UP/19
IGEM/UP/19 is the Institute of Gas Engineers and Managers standard for gas systems in catering premises. It is the primary technical reference Gas Safe engineers use for commercial kitchen installations in the UK. Under IGEM/UP/19, gas interlock systems are required in all new commercial kitchen installations and in any kitchen undergoing significant refurbishment.
BS 6173 and the Gas Safety Regulations
BS 6173 is the British Standard for gas-fired catering appliances. It requires that gas supplies to commercial catering equipment are interlocked with the ventilation system. The Gas Safety (Installation and Use) Regulations 1998 place a legal duty on building owners and operators to ensure gas installations are safe. The Health and Safety at Work Act 1974 adds further duties — failing to maintain a functioning interlock system in a kitchen that requires one is a clear breach.
The Health and Safety Executive publishes guidance on these obligations at HSE Gas Safety guidance. In practice, enforcement is triggered by insurance claims, Environmental Health Officer visits, and third-party fire safety inspections, not only by HSE action.
Which Commercial Kitchens Must Have One?
Planning a kitchen fit-out or refurbishment in Buckinghamshire? Brightwork includes gas interlock provision as standard on every commercial kitchen project. Get in touch to discuss your requirements.
Any premises using gas-fired catering appliances under a mechanical extraction canopy requires an interlock. This includes:
Restaurants, cafés, and pubs with kitchen cooking ranges
Hotel kitchens and event catering facilities
School and hospital canteens
Dark kitchens and delivery-only operations
Food manufacturing units with gas-fired processing equipment
Staff canteens in commercial and industrial premises
The requirement applies to new-build kitchens and to refurbishments. Replacing an extraction canopy or adding gas appliances in an existing kitchen triggers the same obligation as a full new installation.
Gas Safe registration is a legal requirement for any engineer working on gas fittings or appliances. Only a Gas Safe registered engineer can install, commission, or service a gas interlock system. Brightwork ensures all gas work on its projects is carried out by Gas Safe registered engineers. Verify any engineer at gassaferegister.co.uk before commissioning work.
Consequences of Operating Without a Gas Interlock System
Operating a commercial kitchen without a functioning interlock system exposes a business to three specific risks.
Enforcement Action
The HSE and local authority environmental health teams have powers to issue improvement notices, prohibition notices, and prosecute under the Health and Safety at Work Act 1974. A prohibition notice closes the kitchen immediately until the issue is resolved.
Insurance Voidance
Most commercial kitchen insurance policies require gas safety compliance as a condition of cover. An incident in a kitchen without a functioning interlock system is likely to result in a refused claim. Insurers increasingly request gas safety documentation, including commissioning certificates, at renewal.
Harm to Staff and Customers
Carbon monoxide poisoning, fire, and explosion are documented consequences of gas appliances operating without active ventilation. These are not theoretical. HSE enforcement records and UK coroner reports include cases directly linked to failed or absent catering gas safety systems.
How a Gas Interlock System Connects to Your Extraction Canopy
A gas interlock system and an extraction canopy are not two separate installations. The airflow sensor sits inside the canopy duct. The solenoid valve connects to the gas supply feeding the appliances below. Both are specified, wired, and commissioned together.
When Brightwork installs a commercial kitchen canopy and extraction system, gas interlock provision is included as standard on every project. No canopy leaves our site without the correct ventilation interlock system in place.
What the Installation Process Involves
Gas interlock installation takes place during the mechanical and electrical fit-out phase — after ductwork and canopy are positioned, before gas appliances are commissioned.
Installation Steps
The Gas Safe engineer fits the solenoid valve to the gas supply line, close to the main gas cock or manifold beneath the canopy.
The airflow sensor (ventilation proving device) is mounted inside the main extraction duct.
Control wiring runs from the sensor to the interlock controller panel and from the panel to the solenoid valve.
The control panel is wall-mounted in an accessible location for kitchen staff.
The engineer commissions the system: extraction is switched off to confirm gas cuts immediately, airflow thresholds are calibrated, and indicator lights are tested.
A commissioning certificate is issued on completion.
A straightforward single-canopy kitchen takes around half a day. Multi-zone sites take proportionally longer. The kitchen does not need to be closed for the full duration, only during the gas and electrical connection works.
Servicing and Maintenance
IGEM/UP/19 requires gas interlock systems to be inspected and tested at minimum once a year by a Gas Safe registered engineer. The annual service covers the solenoid valve, airflow sensor calibration, control panel diagnostics, full interlock sequence test, and an updated service record.
Between annual services, kitchen managers carry out periodic checks. Kitchen staff run a basic operational check at the start of each shift.
Maintenance Schedule
Gas Interlock System — Maintenance Schedule
Task
Frequency
Who Does It
Check extraction is on and control panel shows “gas on” status; confirm appliances light normally
Daily — start of shift
Kitchen staff
Visually inspect control panel for fault lights or error codes
Weekly
Kitchen manager
Check duct for visible blockages or grease build-up around the airflow sensor
Monthly
Kitchen manager
Test the interlock sequence: switch off extraction, confirm gas cuts immediately
Every 3 months
Kitchen manager or engineer
Full service: test solenoid valve, calibrate airflow sensor, inspect wiring and panel, test full interlock sequence, update service record
Annually
Gas Safe registered engineer
Full system inspection and recommissioning if extraction canopy or gas appliances are replaced or moved
After any significant works
Gas Safe registered engineer
How Much Does a Gas Interlock System Cost?
A single-canopy system, including components and installation by a Gas Safe engineer, typically costs between £400 and £900. Annual servicing runs to £100 to £200. Larger kitchens with multiple extraction zones cost proportionally more.
Kitchen / Scenario
Estimated Cost (Supply + Install)
Notes
Small café or takeaway (single gas hob, one canopy zone)
£400 – £600
Basic single-channel system, straightforward wiring run
Mid-size restaurant kitchen (2–3 gas appliances, one canopy zone)
£600 – £900
Standard system; may require additional solenoid if appliances are on separate supplies
Large restaurant or hotel kitchen (multiple zones, several gas appliances)
£900 – £1,800+
Multi-channel controller; price rises with number of zones and cable run length
Annual service visit (any size)
£100 – £200
Gas Safe engineer; includes test, calibration and updated service record
Recommissioning after refurbishment (existing system)
£150 – £350
Required when canopy or appliances are replaced — not optional under IGEM/UP/19
Figures are typical UK market estimates for 2026. Get three quotes from Gas Safe registered contractors. Costs vary by region, site access, and existing wiring condition.
Gas Interlocks in a Restaurant Refurbishment
Replacing an extraction canopy, adding gas appliances, or reconfiguring a kitchen layout during a restaurant refurbishment triggers the same obligations as a new installation. Under IGEM/UP/19, an existing interlock connected to a new canopy is not compliant. The two must be recommissioned together by a Gas Safe engineer and a new commissioning certificate issued before the kitchen returns to service.
Brightwork coordinates all gas and ventilation work as part of a single project scope. Gas and extraction are signed off together before the kitchen is handed back.
Conclusion
For most UK commercial kitchens using gas appliances under mechanical ventilation, a gas interlock system is a legal requirement under IGEM/UP/19 and BS 6173. It applies to new builds and to refurbishments. It takes around half a day to fit, costs from £400, and protects your staff, your insurance position, and your ability to trade.
If you are planning a new kitchen, replacing your extraction canopy, or carrying out a restaurant refurbishment in Buckinghamshire or the surrounding area, Brightwork manages the full extraction and gas safety specification as part of every project. Every installation is signed off by Gas Safe registered engineers and a commissioning certificate is issued as standard.
Planning a commercial kitchen fit-out or refurbishment in Buckinghamshire or the surrounding area? Brightwork manages the full extraction and gas safety specification — including gas interlock provision — as part of every project. Call us on +44 7405 271831 or get in touch to discuss your requirements: https://brightworkbuilders.co.uk/contact/
Frequently Asked Questions
Can I install a gas interlock system myself?
No. The Gas Safety (Installation and Use) Regulations 1998 require that any work on gas fittings is carried out by a Gas Safe registered engineer. The solenoid valve is a gas fitting. Self-installation is illegal and would void any associated insurance cover.
How much does a gas interlock system cost?
A basic single-canopy system typically costs between £400 and £900 including installation by a Gas Safe engineer. Annual servicing is typically £100–£200. See the cost breakdown table above for typical figures by kitchen type.
What is the difference between a gas interlock and a CO detector?
A gas interlock controls whether gas can flow, based on whether ventilation is physically running. A CO detector monitors the air for carbon monoxide and triggers an alarm if levels become dangerous. Both serve different purposes and both are recommended. The interlock prevents the conditions for CO to build up. The CO detector gives a warning if levels rise despite ventilation being in operation.
How do I reset a gas interlock system after it trips?
Switch the extraction system back on and wait for the airflow sensor to confirm adequate airflow is running. The interlock controller should display a “gas on” status within a few seconds and the solenoid valve will reopen automatically. If gas does not restore after extraction is confirmed running, there is a fault in the sensor, panel, or valve — call a Gas Safe engineer. Do not attempt to bridge or bypass the solenoid valve; bypassing a gas interlock is illegal under the Gas Safety Regulations.
My interlock keeps tripping the gas off — what should I do?
Do not bypass the interlock. The most common causes of nuisance tripping are a dirty airflow sensor, a partially blocked duct reducing airflow below the detection threshold, or a failing control panel component. Call a Gas Safe engineer to diagnose and fix the fault. The interlock is working correctly — it is detecting a ventilation issue that needs addressing.
Does a gas interlock system need a certificate?
Yes. A Gas Safe engineer issues a commissioning certificate when a system is installed or recommissioned. Keep it with your gas safety documentation. You may be required to produce it during an Environmental Health inspection or at insurance renewal. If you cannot locate a certificate for an existing system, have a Gas Safe engineer inspect, test, and reissue one.
Is a gas safety certificate the same as a commissioning certificate?
No. A gas safety certificate (CP12) covers annual safety checks on gas appliances. A commissioning certificate is specific to the gas interlock system and records that it has been installed, calibrated, and tested to the correct specification. Both are required — one for the appliances, one for the interlock system itself.
Gas Interlock System for Commercial Kitchens: What It Is and Do You Need One?
A gas interlock system for commercial kitchens is a legal safety requirement for most UK premises operating gas appliances under mechanical ventilation. If you are planning a new kitchen fit-out or refurbishment, this guide explains how the system works, what UK regulations require, and whether your kitchen needs one.
What Is a Gas Interlock System?
A gas interlock system is a safety device that automatically cuts the gas supply to kitchen appliances when the extraction ventilation stops or fails.
The system links your gas supply directly to your kitchen extraction and ventilation. When extraction is running, gas flows to your appliances. When extraction stops or fails, the interlock shuts the gas supply off automatically.
This prevents a dangerous build-up of combustion by-products — carbon monoxide, nitrogen dioxide, and heat — that accumulate whenever gas appliances run without active ventilation. The system also cuts the gas when staff switch extraction off at the end of service, so no appliance can run unattended without ventilation.
How It Works
When a chef lights a gas range, the extraction fan is already running. The interlock’s airflow sensor detects that air is moving through the duct and sends a signal to the control panel. The control panel confirms ventilation is active and holds the gas solenoid valve open. If the fan fails, a duct blockage reduces airflow, or staff switch the extraction off, the sensor no longer detects sufficient airflow. The interlock controller triggers and the solenoid valve closes, cutting gas to every appliance on that circuit.
The Four Key Components
Some installations also integrate a carbon monoxide detector, which provides a separate alarm layer if CO levels rise regardless of ventilation status.
Is a Gas Interlock System a Legal Requirement in the UK?
Yes — under IGEM/UP/19 and BS 6173, a gas interlock system is a legal requirement for all new commercial kitchen installations and significant refurbishments in the UK.
Two standards set the specific obligations.
IGEM/UP/19
IGEM/UP/19 is the Institute of Gas Engineers and Managers standard for gas systems in catering premises. It is the primary technical reference Gas Safe engineers use for commercial kitchen installations in the UK. Under IGEM/UP/19, gas interlock systems are required in all new commercial kitchen installations and in any kitchen undergoing significant refurbishment.
BS 6173 and the Gas Safety Regulations
BS 6173 is the British Standard for gas-fired catering appliances. It requires that gas supplies to commercial catering equipment are interlocked with the ventilation system. The Gas Safety (Installation and Use) Regulations 1998 place a legal duty on building owners and operators to ensure gas installations are safe. The Health and Safety at Work Act 1974 adds further duties — failing to maintain a functioning interlock system in a kitchen that requires one is a clear breach.
The Health and Safety Executive publishes guidance on these obligations at HSE Gas Safety guidance. In practice, enforcement is triggered by insurance claims, Environmental Health Officer visits, and third-party fire safety inspections, not only by HSE action.
Which Commercial Kitchens Must Have One?
Planning a kitchen fit-out or refurbishment in Buckinghamshire? Brightwork includes gas interlock provision as standard on every commercial kitchen project. Get in touch to discuss your requirements.
Any premises using gas-fired catering appliances under a mechanical extraction canopy requires an interlock. This includes:
The requirement applies to new-build kitchens and to refurbishments. Replacing an extraction canopy or adding gas appliances in an existing kitchen triggers the same obligation as a full new installation.
For a full breakdown of gas safety obligations in commercial kitchens — pipework, appliance connections, and engineer qualifications — read our related guide: Gas Safe commercial kitchen connections: 7 essential checks.
Gas Safe registration is a legal requirement for any engineer working on gas fittings or appliances. Only a Gas Safe registered engineer can install, commission, or service a gas interlock system. Brightwork ensures all gas work on its projects is carried out by Gas Safe registered engineers. Verify any engineer at gassaferegister.co.uk before commissioning work.
Consequences of Operating Without a Gas Interlock System
Operating a commercial kitchen without a functioning interlock system exposes a business to three specific risks.
Enforcement Action
The HSE and local authority environmental health teams have powers to issue improvement notices, prohibition notices, and prosecute under the Health and Safety at Work Act 1974. A prohibition notice closes the kitchen immediately until the issue is resolved.
Insurance Voidance
Most commercial kitchen insurance policies require gas safety compliance as a condition of cover. An incident in a kitchen without a functioning interlock system is likely to result in a refused claim. Insurers increasingly request gas safety documentation, including commissioning certificates, at renewal.
Harm to Staff and Customers
Carbon monoxide poisoning, fire, and explosion are documented consequences of gas appliances operating without active ventilation. These are not theoretical. HSE enforcement records and UK coroner reports include cases directly linked to failed or absent catering gas safety systems.
How a Gas Interlock System Connects to Your Extraction Canopy
A gas interlock system and an extraction canopy are not two separate installations. The airflow sensor sits inside the canopy duct. The solenoid valve connects to the gas supply feeding the appliances below. Both are specified, wired, and commissioned together.
When Brightwork installs a commercial kitchen canopy and extraction system, gas interlock provision is included as standard on every project. No canopy leaves our site without the correct ventilation interlock system in place.
What the Installation Process Involves
Gas interlock installation takes place during the mechanical and electrical fit-out phase — after ductwork and canopy are positioned, before gas appliances are commissioned.
Installation Steps
A straightforward single-canopy kitchen takes around half a day. Multi-zone sites take proportionally longer. The kitchen does not need to be closed for the full duration, only during the gas and electrical connection works.
Servicing and Maintenance
IGEM/UP/19 requires gas interlock systems to be inspected and tested at minimum once a year by a Gas Safe registered engineer. The annual service covers the solenoid valve, airflow sensor calibration, control panel diagnostics, full interlock sequence test, and an updated service record.
Between annual services, kitchen managers carry out periodic checks. Kitchen staff run a basic operational check at the start of each shift.
Maintenance Schedule
Gas Interlock System — Maintenance Schedule
How Much Does a Gas Interlock System Cost?
A single-canopy system, including components and installation by a Gas Safe engineer, typically costs between £400 and £900. Annual servicing runs to £100 to £200. Larger kitchens with multiple extraction zones cost proportionally more.
Figures are typical UK market estimates for 2026. Get three quotes from Gas Safe registered contractors. Costs vary by region, site access, and existing wiring condition.
Gas Interlocks in a Restaurant Refurbishment
Replacing an extraction canopy, adding gas appliances, or reconfiguring a kitchen layout during a restaurant refurbishment triggers the same obligations as a new installation. Under IGEM/UP/19, an existing interlock connected to a new canopy is not compliant. The two must be recommissioned together by a Gas Safe engineer and a new commissioning certificate issued before the kitchen returns to service.
Brightwork coordinates all gas and ventilation work as part of a single project scope. Gas and extraction are signed off together before the kitchen is handed back.
Conclusion
For most UK commercial kitchens using gas appliances under mechanical ventilation, a gas interlock system is a legal requirement under IGEM/UP/19 and BS 6173. It applies to new builds and to refurbishments. It takes around half a day to fit, costs from £400, and protects your staff, your insurance position, and your ability to trade.
If you are planning a new kitchen, replacing your extraction canopy, or carrying out a restaurant refurbishment in Buckinghamshire or the surrounding area, Brightwork manages the full extraction and gas safety specification as part of every project. Every installation is signed off by Gas Safe registered engineers and a commissioning certificate is issued as standard.
Planning a commercial kitchen fit-out or refurbishment in Buckinghamshire or the surrounding area? Brightwork manages the full extraction and gas safety specification — including gas interlock provision — as part of every project.
Call us on +44 7405 271831 or get in touch to discuss your requirements: https://brightworkbuilders.co.uk/contact/
Frequently Asked Questions
Can I install a gas interlock system myself?
No. The Gas Safety (Installation and Use) Regulations 1998 require that any work on gas fittings is carried out by a Gas Safe registered engineer. The solenoid valve is a gas fitting. Self-installation is illegal and would void any associated insurance cover.
How much does a gas interlock system cost?
A basic single-canopy system typically costs between £400 and £900 including installation by a Gas Safe engineer. Annual servicing is typically £100–£200. See the cost breakdown table above for typical figures by kitchen type.
What is the difference between a gas interlock and a CO detector?
A gas interlock controls whether gas can flow, based on whether ventilation is physically running. A CO detector monitors the air for carbon monoxide and triggers an alarm if levels become dangerous. Both serve different purposes and both are recommended. The interlock prevents the conditions for CO to build up. The CO detector gives a warning if levels rise despite ventilation being in operation.
How do I reset a gas interlock system after it trips?
Switch the extraction system back on and wait for the airflow sensor to confirm adequate airflow is running. The interlock controller should display a “gas on” status within a few seconds and the solenoid valve will reopen automatically. If gas does not restore after extraction is confirmed running, there is a fault in the sensor, panel, or valve — call a Gas Safe engineer. Do not attempt to bridge or bypass the solenoid valve; bypassing a gas interlock is illegal under the Gas Safety Regulations.
My interlock keeps tripping the gas off — what should I do?
Do not bypass the interlock. The most common causes of nuisance tripping are a dirty airflow sensor, a partially blocked duct reducing airflow below the detection threshold, or a failing control panel component. Call a Gas Safe engineer to diagnose and fix the fault. The interlock is working correctly — it is detecting a ventilation issue that needs addressing.
Does a gas interlock system need a certificate?
Yes. A Gas Safe engineer issues a commissioning certificate when a system is installed or recommissioned. Keep it with your gas safety documentation. You may be required to produce it during an Environmental Health inspection or at insurance renewal. If you cannot locate a certificate for an existing system, have a Gas Safe engineer inspect, test, and reissue one.
Is a gas safety certificate the same as a commissioning certificate?
No. A gas safety certificate (CP12) covers annual safety checks on gas appliances. A commissioning certificate is specific to the gas interlock system and records that it has been installed, calibrated, and tested to the correct specification. Both are required — one for the appliances, one for the interlock system itself.