Connections, flues and dampers, the rooms that need room-sealed appliances, and the checks required after installing or working on a gas appliance.
Part E of the Gas Safety (Installation and Use) Regulations covers the appliance itself: where it may go, how it is connected and flued, and what is checked before it is left in use. No appliance may be installed unless it can be used without danger.
Before and during installation
- Used appliances. A second-hand appliance may be installed only after the installer has verified it is in a safe condition for further use (regulation 26(3)). Paperwork from a previous home, or commissioning afterwards, does not replace that check.
- Flued appliances connect rigidly. A flued domestic appliance is connected by a permanently fixed rigid pipe, never a bayonet and hose (26(2)), whether it is room-sealed or open-flued. Flexible connections are for appliances such as freestanding cookers, designed to be pulled out and with no flue.
- Isolation, access and instructions. Provide a means of shutting off the gas at the appliance inlet where reasonably practicable, keep the appliance readily accessible for maintenance, and leave the manufacturer's instructions for the owner or occupier.
Flues and dampers
- The flue must be suitable and in a proper condition for the appliance.
- Where a flue pipe enters a brick or masonry chimney, the seal between them must be inspectable (27(2)). A joint that cannot be seen cannot be checked at commissioning or at any later service.
- A flue inside an enclosure needs the enclosure sealed so that any spillage cannot pass into any room other than the appliance's own (27(3)). Room-sealed flues can leak too, so this applies to them.
- A manually operated damper may not be fitted to serve a domestic appliance (32(2)); an existing one is fixed permanently open before a domestic appliance is connected (32(3)). Interlocking is only for automatic dampers.
Rooms that need room-sealed appliances
- Bathrooms and shower rooms: room-sealed only (30(1)).
- Rooms used for sleeping: a gas fire, other space heater or water heater over 14 kW gross input must be room-sealed. At 14 kW or less it must be room-sealed or have a safety control that shuts it down before combustion products build up to a dangerous level.
- Instantaneous water heaters, in any room: room-sealed, or fitted with that shut-down safety control (30(3)). An open-flued one in a kitchen needs the control; the 14 kW figure belongs to the sleeping-room rule. A CO alarm warns but shuts nothing down, so it cannot take the control's place.
- Cupboards count. A cupboard or compartment within one of those rooms, or next to it with an air vent into it, is treated as part of that room (30(4)). Keeping the door shut changes nothing; the vent is the connection.
After installing, and after any work
- After installation, test the connection for tightness and examine the appliance: it meets the regulations, runs at the manufacturer's operating pressure, is installed to the instructions and has all its gas safety controls working (33(1)). If it needs adjustment that cannot be made, disconnect it or seal it off with an appropriate fitting (33(2)). Turning it off and leaving a note leaves it connected.
- After work on an appliance, examine the effectiveness of any flue, the supply of combustion air, the operating pressure or heat input, and its operation so that it functions safely (26(9)). Where pressure or heat input cannot reasonably be examined, examine its combustion performance instead, using a suitable flue gas analyser. Report any defect to the responsible person.
- Spillage checks. Take the warm-up period, test conditions and any repeat from the appliance instructions: five minutes if that is what the manufacturer specifies, but no single time suits every appliance. A passed spillage check does not prove every flue joint sound.
- Suspected danger. If you know or suspect an appliance cannot be used safely, take all reasonably practicable steps to tell the responsible person, and the owner where different.