Isolating and safely reconnecting a gas appliance

Isolating an appliance for work

1. Choose the valve. Use the appliance isolation valve for the appliance you are working on, so the rest of the installation stays in supply. Closing the emergency control valve would shut every appliance off unnecessarily.
2. Isolate the gas, not just the controls. Turning the control knob off, setting it to pilot or cutting the electrical supply all leave gas at the appliance. Close a suitable isolation valve upstream of the connection you will open.
3. Prove it off. Confirm there is no gas at the appliance before you undo anything: valves stick and plugs pass.
4. Seal open ends. Cap or plug any open end with a fitting made for the pipe, and prove it gas-tight by test. Tape, or a closed valve with an open end beyond it, is not enough.
5. Prove the reconnection tight. Before the appliance is left in use, tightness-test under pressure, covering every joint you disturbed. Leak-detection fluid before the gas is back on, or a gas rate at the meter, does not prove a joint.
6. Recommission. Relight and check the appliance operates correctly, including its safety devices.

Taking an unsafe appliance out of use

1. Ask permission. Explain the danger to the responsible person and ask; you generally cannot turn off or disconnect a customer's appliance without consent.
2. Make it safe. Immediately Dangerous: disconnect and seal the supply to the appliance with an appropriate fitting; a user control switched off does not complete this. At Risk, where turning off removes the risk: turn off the gas supply.
3. Label and notify. Attach a clear DANGER DO NOT USE label and give the responsible person a written warning notice recording the defect, its classification, the action taken and the work needed. Keep your own record, and if the user is not the owner, tell the owner or managing agent in writing.
4. Handle refusals. Refusal to sign: record it and still leave the label and notice. At Risk turn-off refused: warn, label, advise against use and record the refusal. Immediately Dangerous disconnection refused: contact the natural-gas emergency contact centre at once (for LPG, the gas supplier) and record the reference and time.

Turning off an At Risk appliance

Turning off takes the appliance out of use. Use the first of these that you can:

1. Close the gas isolation valve to the appliance.
2. If you cannot, remove the appliance's electrical fuse.
3. If neither is possible, turn off the appliance control and fix the warning label to its gas control.

Turning a room thermostat down or a timer to off never counts, because anyone can turn it back without knowing why. Turning off is not isolation for work: before you open a joint, you still isolate the gas and prove it off.

A few At Risk situations, such as a building put up over a plastic gas service pipe, are not made safer by turning off. They get a warning notice saying who to contact, and no DANGER DO NOT USE label.

When an Immediately Dangerous disconnection is refused

You can only disconnect with the responsible person's permission. The gas transporter's emergency service has a legal right to enter and disconnect without consent where life or property is in danger, so a refused disconnection is passed to them at once; recording it is not enough.

1. Try to turn the appliance off, and explain again why it must not be used.
2. For natural gas, call the Gas Emergency Contact Centre on 0800 111 999 (in Northern Ireland, 0800 002 001), not the customer's energy supplier. For LPG, call the gas supplier's emergency number.
3. Say it is Immediately Dangerous, and give the address, the appliance and where it is, the fault, the responsible person's name, and your business registration and engineer ID numbers.
4. Write down the job reference number and the time of the call.
5. Where you reasonably can, stay nearby to explain the danger to their engineer.

The refusal does not change the classification. The appliance is still Immediately Dangerous and still gets the label and the warning notice.