The Complete CKR1 Guide: Domestic Gas Cookers

CKR1 covers domestic gas cookers — freestanding, slide-in and built-in hobs and ovens. A cooker is usually a flueless (Type A) appliance: its products go into the room, so siting, ventilation and stability all matter. This guide maps the topic and links to a full guide on each part. You need CCN1 as well as CKR1 to work on cookers, and only a Gas Safe registered engineer may do so.

Siting and connection

A cooker must be sited away from anything that could catch fire and where it can be used safely. A freestanding cooker is usually connected with a flexible hose (BS EN 14800) to a self-sealing bayonet connector — push-and-twist, sealing automatically when the cooker is pulled out. The hose must not pass through walls or be kinked, and the cooker still needs a tightness-tested supply.

Stability — the anti-tip device

A freestanding cooker can tip if someone leans or sits on an open oven door, so it must be secured with a stability device — a chain or bracket. It's a required safety item, checked at commissioning. Read the full guide to cooker stability & anti-tip devices →

Flame supervision

A flame supervision device (FSD) shuts the gas off if a burner flame goes out — protecting against a hob being left on unlit or a flame being blown out. Modern hobs, grills and ovens have them; you test they operate correctly. Read the full guide to flame supervision devices →

Ventilation by room volume

Because a cooker is flueless, the room must be big enough and have an air supply. The rules step with room volume — a very small room needs purpose-provided ventilation, a larger one may need only an openable window. Read the full guide to cooker ventilation by room volume →

Clearances to combustibles

There must be safe space above and beside the hotplate, and care taken with nearby combustible surfaces and overhead cupboards or canopies. The figures come from BS 6172 and the manufacturer's instructions. Read the full guide to clearances to combustible surfaces →

Commissioning checks

Bringing a cooker into use pulls the topics together: tightness test the supply, check the gas rate and burner pressure, confirm each FSD operates, verify the stability device, check ventilation and clearances, and check combustion (a clean blue hob flame; yellow tipping warns of a problem). Hand over the instructions to the customer.

1. Standard: BS 6172 (ventilation via BS 5440-2); MIs take precedence.
2. Cooker = flueless (Type A): products enter the room.
3. Connection: BS EN 14800 hose to a self-sealing bayonet; no passing through walls.
4. Stability device (chain/bracket) is required and checked on commissioning.
5. FSD shuts off gas on flame loss — test it operates.
6. Ventilation steps with room volume; small rooms need a permanent vent.
7. Clearances per BS 6172/MIs; check combustion (blue flame, no yellow tipping).