How air, liquid and gas autonomous heaters work, what to consider when choosing one, and why the air conditioner needs a check after winter.
Autonomous heaters have become popular because they save fuel compared with running the vehicle’s own heating system all winter. Air heaters burn fuel in a chamber and blow warm air into the cabin; liquid heaters sit under the bonnet, warm both engine and interior and can be timer-controlled remotely. Gas systems are mainly suited to truck cabs.
Key points when choosing a heater:
- Vehicle size and design
- Capacity of the electrical system
- How often it will be used and the local climate
For passenger cars, air and liquid types are the usual choice: air heaters are simple and affordable, while liquid heaters also warm the engine. The air conditioner, idle over winter, should also be checked with service equipment in spring.