Heater
- Parking heater - heats the passenger compartment, if necessary, when the parking climate control's preconditioning is activated.
- Additional heater - heats the passenger compartment and engine, if necessary, during driving.
Either a fuel-driven heater or an electric heater is used, depending on the market1.
The heater is fitted in the front right-hand wheel housing.
Note
When the heater is running2, smoke may be emitted from the right-hand front wheel housing and a low hum may be heard. A ticking sound from the fuel pump may also be heard from the rear section of the car. This is perfectly normal.
Battery and charging
The heater is powered by the car's hybrid battery. If the charge level of the hybrid battery is too low, then the heater is switched off automatically and the driver display shows a message.
Note
Fuel and refuelling3
![P5-1507–Climate–Fuel cap heater warning](https://www.volvocars.com/images/support/imgebe460fef6202744c0a8015223b79e71_1_--_--_VOICEpnghigh.png?imwidth=1280)
The heater uses fuel from the car's normal fuel tank.
If the car is parked on a steep hill, the front of the car should point downhill to ensure that there is a supply of fuel to the heater.
If the level in the fuel tank is too low then the heater is switched off automatically and the driver display shows a message.
Note
Warning
Fuel which spills out could be ignited. Switch off the fuel-driven heater before starting to refuel.
![P6-1746-XC40-DIM tell tale symbol pre-heater](https://www.volvocars.com/images/support/img49d661dc0eac3d9cc0a801521e63ed04_1_--_--_VOICEpnghigh.png?imwidth=1280)
Check in the driver display that the heater is switched off. This symbol is lit when it is working as a parking heater.