We supply and fit Gas Interlocking Systems (GIS) that are now legally required in commercial kitchens.

A Gas Interlock checks the kitchen extract fan is running before allowing gas in to the kitchen. If the fan stops, it will cut off the gas supply to prevent a build-up of dangerous fumes.

You will need a gas interlock in the following circumstances*:
  • On installation of a new extraction/ventilation canopy
  • On installation of a new gas pipework run
  • If you wish to sell the business or premises
  • On installation of a new cook line or layout
  • Fitting of any Category ‘B’ equipment e.g. combination ovens, deep fat fryers, grills, charcoal griddles, including replacements to an existing layout
* This is only general information and not a statement of law, always consult a COMCAT Gas Safe engineer. Most restaurants, takeaways, cafés and pubs need a gas interlock to comply with current standards, those that don’t will have this noted on their gas certificate and the local authority may insist on fitment as they have been a requirement on new installations since September 2001.


These are the key parts of a gas interlock system:
Gas interlock control panel for catering (automatic)
Control panel & emergency stop
Far East’s gas interlock control panel is fully automatic and includes the required emergency stop button. It current monitors two fans (can be expanded upto 4). Some panels can be complicated with many buttons, keys switches, displays and sensors.
Gas solenoid valve for gas interlock
Solenoid valve
This is an electric valve which turns the gas on and off, it is controlled by the aforementioned control panel. The price of the valve depends on how big the gas pipe is.
Fan current monitor sensor for gas interlock
Current monitoring gas interlock
Measures electricity being used by the fan; very reliable because there are no moving parts and nothing can get blocked. This is the type we supply.
Pressure sensor switch for gas interlock
Pressure sensing gas interlock
An air pressure switch detects when the fan is running. They are cheap but unreliable; the switches get blocked by grease and dirt, hoses are accidentally disconnected and the switch’s moving parts jam or break. We strongly advise against their use in commercial catering.
SNS Northern Merlin interlock panel with fan speed control. Medem CO2 Intelligas Ventam Trent
Additional sensors & connections
Some control panels have additional connections for fire alarms, Carbon Monoxide and CO2 detector sensors, remote emergency stops, fan speed control and so on. These are not normally required but we can provide them.
Proving assembly with solenoids (weep bypass) for gas interlock
Proving gas interlock
After checking the fan (by air pressure or electric current), this tests (pressure proves) the gas pipes for leaks and open valves before allowing gas to flow. They are more expensive but usually only required where there is pre-1997 equipment without Flame Safety Devices/thermocouples (FSDs) that cut the gas off if the flame is extinguished. With such old equipment it can be more cost effective to replace the appliance.


How much is a gas interlock?

Our gas interlock is simple to use, reliable and great value. The price depends on how big the gas pipe to your kitchen is. Below are typical prices for supply and simple install of gas interlock system:

  • £300 control panel supply only (excludes solenoid and installation, includes two induction current sensors)
  • £1150 28 mm copper (1” typical capacity U6 65 kW)
  • £1250 35 mm copper (1¼” typical capacity U16 150 kW)
  • £1350 42 mm copper (1½” typical capacity U16 170kW or U25 215 kW)
  • £1500 2” iron BMI (typical capacity U25 250kW)
  • £470 upgrade to gas pressure proving
Every installation is different so prices may differ from those above, please contact us for a quote.