Propane and butane are both LPG (liquefied petroleum gas). They are stored as a liquid under pressure and boil off into gas as you use them. The difference that matters is the temperature they stop boiling at.
| Propane | Butane | |
|---|---|---|
| Cylinder colour | Red (or composite patio bottles) | Yellow / blue (Campingaz) |
| Stops working below | About −42°C | About 0°C |
| Best for | Outdoors, all year: patio heaters, barbecues, catering, site heaters, home heating | Indoors: cabinet heaters, caravans in summer, gas fires |
| Regulator | 37mbar screw-on (or 27mm clip-on for patio gas) | 21mm clip-on, 28–29mbar |
The rule of thumb
If the cylinder lives outside, buy propane. If it lives inside and you use it in the warmer months, butane is cleaner and quieter.
Can I swap one for the other?
Not without changing the regulator, and only if the appliance is rated for both. Check the appliance plate or ask us before you switch.