Service
Gas Interlock System Installation
We supply and install complete commercial gas interlock systems — controller, air proving sensor, emergency stop and normally closed solenoid valve — then commission and certify the installation to BS 6173.
- Complete interlock kits fitted in one visit where pipework allows
- 28mm, 35mm and larger screwed or flanged solenoid valves sized to the gas rate
- Commissioned, tested and documented by Gas Safe registered commercial engineers
System architecture
What a full installation includes
- Site survey: gas rate, incoming pipe size, extract and make-up air arrangement, existing controls
- Interlock controller or panel mounted in an accessible position near the kitchen entrance
- Proof of ventilation device — differential air pressure switch across the extract fan, duct airflow sensor, or fan current monitor
- Normally closed gas solenoid valve installed in the correct flow direction, on a horizontal run with the coil upright wherever possible
- Latching emergency gas shut-off button in an escape route position
- Interconnecting wiring in appropriate containment, fused and labelled at the isolator
- Commissioning: fan fail test, e-stop test, valve closure timing, tightness test and gas soundness
- Certification, labelling and a handover walkthrough with the kitchen team
Choosing the right kit and valve size
The solenoid valve must match the incoming gas pipe size and the total appliance gas rate — undersizing causes pressure drop and appliance underperformance at full load. Most commercial kitchens fall between 28mm and 54mm (or RP 1" to RP 2" screwed valves).
| Typical pipe size | Valve | Common use |
|---|---|---|
| 22–28mm | RP 3/4"–1" normally closed | Small kitchens, single range, mobile catering bays |
| 35mm | RP 1 1/4" normally closed | Restaurant kitchens with range, fryers and grill |
| 42mm | RP 1 1/2" normally closed | Larger production kitchens, school and care home kitchens |
| 54mm+ | RP 2" or flanged | Hotel, hospital and multi-suite kitchens |
How long installation takes
A straightforward interlock retrofit onto existing accessible pipework is usually a half-day to a full day. Adding a new valve pocket, re-routing gas pipework, or installing air proving in a long duct run can extend this. We work outside service hours where a kitchen cannot close.
Frequently asked questions
How much does gas interlock installation cost?
Most commercial kitchen installations fall in a predictable range depending on valve size and cable routes. See our installation cost guide for a breakdown, or send photos of your gas entry point and fan for a fixed quote.
Can you install an interlock without closing the kitchen?
Usually yes. The gas needs isolating while the valve is fitted, so we normally do that before service or overnight, then commission and hand back the same visit.
Do I need a new panel or can the existing one be reused?
If the existing controller is a current model and the fault is only in a sensor or valve, we repair in place. Obsolete panels with no spares available are replaced with an equivalent Merlin, Medem or Intelligas system.
Related guides
Gas Interlock Systems
The pillar guide: how interlocks work, standards and fault-finding.
Installation Cost
What a gas interlock system costs to supply, fit and certify.
Wiring Diagrams
Merlin CT1250, Banico and generic interlock wiring explained.
Regulations & Law
BS 6173, IGEM/UP/19 and whether an interlock is a legal requirement.
Gas Solenoid Valves
Normally closed automatic shut-off valves and diagnostics.
Sensors & Controls
Air pressure switches, airflow sensors, current monitors, e-stops.
Parts in stock — ready to fit
Held in UK stock and carried on our vans, so most jobs are fixed in one visit.
Replacement gas interlock systems
Merlin, Medem, Intelligas, S&S Northern
In stock today
Air pressure switches
Fan & gas proving pressure switches
In stock today
Gas solenoid valves
Normally closed safety shut-off valves
In stock today
Quick release gas catering hoses
Commercial ranges, bays & mobile catering
In stock today
Super universal thermocouples
Fits most commercial gas appliances
In stock today
Need a part fitted?
Same-day engineer dispatch with these parts on the van.
Gas Safe Registered
Commercial catering & plant
24/7 UK Response
Same-day emergency dispatch
Vetted Engineers
DBS checked for schools & care
Transparent Pricing
Fixed callout, quoted parts
Areas we cover
Gas interlock installation, servicing and emergency repair across 34 areas of London, Surrey and the M25 towns — 372 postcode districts in total.
London
Central London →
EC1, EC2, EC3, EC4, WC1, WC2 +5 more
East London →
E1, E2, E3, E4, E5, E6 +14 more
North London →
N1, N2, N3, N4, N5, N6 +16 more
North West London →
NW1, NW2, NW3, NW4, NW5, NW6 +5 more
South East London →
SE1, SE2, SE3, SE4, SE5, SE6 +22 more
South West London →
SW1, SW2, SW3, SW4, SW5, SW6 +14 more
West London →
W1, W2, W3, W4, W5, W6 +8 more
Bromley & Beckenham →
BR1, BR2, BR3, BR4, BR5, BR6 +2 more
Croydon →
CR0, CR1, CR2, CR3, CR4, CR5 +4 more
Harrow & Wembley →
HA0, HA1, HA2, HA3, HA4, HA5 +4 more
Ilford, Romford & East Boroughs →
IG1, IG2, IG3, IG4, IG5, IG6 +25 more
Sutton & Morden →
SM1, SM2, SM3, SM4, SM5, SM6 +1 more
Hounslow, Twickenham & Staines →
TW1, TW2, TW3, TW4, TW5, TW6 +14 more
Uxbridge, Hayes & Southall →
UB1, UB2, UB3, UB4, UB5, UB6 +5 more
Enfield & Barnet →
EN1, EN2, EN3, EN4, EN5, EN6 +5 more
Bexley, Sidcup & Dartford →
DA1, DA2, DA3, DA4, DA5, DA6 +12 more
Surrey
Kingston upon Thames →
KT1, KT2, KT3, KT4, KT5, KT6 +1 more
Epsom & Ewell →
KT17, KT18, KT19, KT20, KT21
Esher, Walton & Weybridge →
KT7, KT8, KT10, KT11, KT12, KT13 +3 more
Leatherhead & Dorking →
KT22, KT23, KT24, RH3, RH4, RH5
Guildford →
GU1, GU2, GU3, GU4, GU5
Woking →
GU21, GU22, GU23, GU24
Camberley & Farnborough →
GU14, GU15, GU16, GU17, GU18, GU19 +3 more
Farnham & Godalming →
GU6, GU7, GU8, GU9, GU10, GU11 +4 more
Redhill & Reigate →
RH1, RH2, RH6, RH7, RH8, RH9 +2 more
Runnymede, Egham & Virginia Water →
TW20, GU25, KT16
M25 & Home Counties
Watford & Rickmansworth →
WD3, WD4, WD5, WD6, WD7, WD17 +5 more
St Albans & Hatfield →
AL1, AL2, AL3, AL4, AL5, AL6 +4 more
Hemel Hempstead & Amersham →
HP1, HP2, HP3, HP4, HP5, HP6 +5 more
Slough, Windsor & Maidenhead →
SL0, SL1, SL2, SL3, SL4, SL5 +4 more
Brentwood, Epping & Harlow →
CM1, CM2, CM11, CM12, CM13, CM14 +6 more
Sevenoaks & Swanley →
TN13, TN14, TN15, TN16, BR8
Grays, Thurrock & Lakeside →
RM15, RM16, RM17, RM18, RM19, RM20 +1 more
Orpington & the A20 Corridor →
BR5, BR6, BR7, DA3, DA4, DA13 +2 more