Gas should only flow when your extraction is working. We supply, install and commission BS6173 gas interlocking for commercial kitchens across the UK.
A gas interlock stops gas reaching cooking equipment unless the extraction system is running with enough airflow. A sensor detects the airflow and only then lets a normally closed gas solenoid valve open; if the extraction fails or is switched off, the gas is cut automatically. BS6173 requires it on new installations.
All new installations, and some existing installations where modifications or new equipment is being installed, must have a gas interlocking system to comply with BS6173.
The interlock prevents the gas from being turned on until the ventilation system is fully operational. It uses an air pressure sensor or current monitoring to detect that the canopy is working with sufficient air flow, and only then allows a normally closed gas solenoid valve on the incoming gas supply to open. If the airflow falls below the required level, or the ventilation is switched off, the gas flow is switched off automatically.
HSE's catering information sheet CAIS10 explains that some gas appliances are a type (known as type B) that require a flue under the Gas Safety (Installation and Use) Regulations 1998. Where extraction serves as the flue, it is considered a flue and requires an appropriate interlocking system connecting the airflow to the gas supply. New installations, and some existing ones where equipment is modified or added, must comply with BS 6173. If you are not sure whether your kitchen is covered, ask us to check at survey.
A sensor, usually an air pressure switch or a current-monitoring device, detects that the extract fan is running and moving air. Only then is a normally closed gas solenoid valve on the incoming gas supply allowed to open. If airflow falls below the required level, or the ventilation is switched off, the valve closes and the gas flow stops. Our systems are also wired to the fresh-air fans where fitted, as on our Rosa's Soho project.
| Part | Job |
|---|---|
| Airflow sensor | Confirms the extract fan is actually moving air |
| Interlock control panel | Checks the signal and keeps the gas valve open only while it is good |
| Gas solenoid valve | Normally closed; shuts off the gas on failure |
| Reset | Allows gas back on once extraction is restored and checked |
An interlock is only as good as its commissioning. The sensor has to be set so it trips when airflow genuinely falls, without tripping every time a filter is slightly dirty. We test the interlock as part of commissioning, and it should be re-tested at maintenance visits. Repeated trips usually point to a real extraction problem, such as clogged filters, a slipping fan belt or missing make-up air, rather than a fault in the interlock itself. Never bypass an interlock. See the full guide, BS6173 gas interlock systems explained, and our wider kitchen extraction service.
A gas interlock stops gas reaching your cooking equipment unless the extraction system is running with enough airflow. If the airflow drops or the extraction is switched off, the gas supply is cut automatically.
All new installations, and some existing installations where modifications or new equipment is being installed, must have a gas interlocking system to comply with BS6173. Talk to us about your kitchen and we will advise.
We supply and install commercial gas kitchen systems that comply with BS6173, with all gas components and catering equipment approved by a commercially registered Gas Safe Register (previously Corgi) installation engineer.
No. A tripping interlock is telling you the extraction is not performing. The fix is to find the cause, such as blocked filters or lack of make-up air.
Gas work must be done by a Gas Safe registered engineer. All our gas components and catering equipment are approved by a commercially registered Gas Safe installation engineer.
No gas supply means no gas interlock, though extraction is still required for ventilation.
At commissioning and as part of regular maintenance. Ask us about a testing schedule that suits your kitchen.
It can be. We wire interlocks to the extract and fresh-air fans where fitted.
Wherever your site is, we survey, design, manufacture and install. Find your nearest area, or call 07759 696007.
