Fault guide
Gas Interlock Won't Reset
A gas interlock that will not reset is doing its job: it is holding the gas closed because one of its safety inputs is not satisfied. The reset button only latches once the panel sees mains power, a healthy emergency stop circuit, proven ventilation and (on proving systems) a sound pipework test.
- Most no-reset calls are an unlatched e-stop, a fan not running, or a pressure switch out of adjustment
- Never bypass, strap out or wedge an interlock input to get the kitchen cooking
- Same-day UK attendance to diagnose, repair and recertify
System architecture
Reset sequence — how it should work
- Extract fan (and make-up air fan where fitted) switched on at the panel or BMS
- Fan runs up and the air pressure switch or airflow sensor makes, proving ventilation
- All emergency stop buttons are out and latched in the healthy position
- Gas detection heads, where fitted, are in a clear, non-alarm state
- Press and hold reset — the panel energises the solenoid valve coil and the gas-on lamp lights
Why it won't latch
| Symptom at the panel | Likely cause | What is needed |
|---|---|---|
| Emergency stop lamp lit | A button pressed in somewhere in the kitchen or plant room | Find and twist-release every e-stop, including ones behind equipment |
| Fan fail lamp lit | Fan not running, belt slipping, isolator off, or pressure switch not making | Fan and airflow proving fault diagnosis |
| No lamps at all | Blown fuse, tripped supply, dead transformer or failed panel | Electrical supply test and panel repair or replacement |
| Resets then drops out seconds later | Marginal airflow proof, dirty filters, intermittent switch or loose terminal | Pressure switch setting and airflow measurement |
| Panel resets but no gas at appliances | Solenoid coil open circuit, valve stuck shut, or manual valve closed | Solenoid valve test and replacement |
| Proving lockout code | Pipework failed the pressure proof — possible leak or open appliance tap | Tightness test before any reset |
Safe checks a kitchen manager can make
- Check every emergency stop button is fully released
- Confirm the extract canopy fan is actually pulling air, not just switched on at the panel
- Check all appliance isolation taps are closed before attempting a reset on a proving system
- Check the kitchen ventilation isolator and the panel's fused supply have not been switched off by cleaners
- Record the exact lamps and codes showing — it speeds up the call-out
If you can smell gas
- Turn off the gas at the emergency control valve and press the emergency stop button
- Do not switch anything electrical on or off, and do not use naked flames
- Open doors and windows, evacuate and keep people clear
- Call the National Gas Emergency Service on 0800 111 999
- Only then call us to make the installation safe and return it to service
Frequently asked questions
Can I bypass the interlock to keep cooking?
No. Bypassing the interlock removes the ventilation safety and makes the installation immediately dangerous and non-compliant with BS 6173. An engineer must find and fix the fault.
Why does the interlock reset then trip again?
That usually means ventilation is only marginally proven — a pressure switch set too close to the actual duct pressure, blocked filters, a slipping fan belt, or a loose terminal breaking the safety circuit intermittently.
How quickly can you attend?
We run a 24/7 UK response desk and carry replacement panels, air pressure switches and solenoid valves in stock, so most no-reset faults are repaired on the first visit.
Will I get paperwork afterwards?
Yes. Every repair is followed by a full interlock test — fan fail, emergency stop and valve closure — and a certificate for your compliance file.
Related guides
Interlock Reset Service
Same-day attendance to reset, prove and recertify the system.
Interlock Fan Fault
Fan fail lamps, airflow switch faults and extract failures.
Solenoid Valve Faults
Valve won't open, keeps closing, buzzing or leaking by.
Emergency Interlock Engineer
24/7 UK call-out when the kitchen has no gas and service is on.
Gas Safety Control Panels
Interlock and proving panels, indicators and diagnostic codes.
Gas Interlock Systems
The pillar guide: how interlocks work, standards and fault-finding.
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