20.2051.05.0000 | Genuine Eberspacher® S3 B5E CS Hydronic Heater 12V

• Passenger cars (from 2.0 L displacement)
• Emergency vehicles
• Vans, large taxis, minivans
• Commercial vehicles, incl. tandem setups with air heaters
• Construction and agricultural machinery
• Motorhomes; also suitable for boats (domestic hot water loops)

• Fuel: Gasoline (petrol)
• Voltage: 12 V
• Heat output: 17,000 BTU (≈ 5.0 kW)
• Fuel consumption: 0.06–0.17 gal/h (0.23–0.67 L/h)
• Power draw: 7–32 W
• Max operating altitude: 10,000 ft (3,048 m)
• Warranty: 2 years
• Dimensions (heater body): 8.4 × 3.5 × 5.6 in (215 × 91 × 144 mm)

• Warm the cabin quickly for driver and passenger comfort

• Preheat the engine coolant to reduce engine wear during cold starts

• Reduce idling time, saving fuel and lowering emissions

• Maintain engine and fluid temperatures in very cold environments

Heating problems

• Cabin stays cold even when the heater is on

• Engine or coolant doesn’t warm up properly

Unusual noises

• Knocking, rattling, or hissing from the heater unit

• Pump or fan noises that sound abnormal

Operational issues

• Heater won’t start or stops running unexpectedly

• Error codes or warning lights on the vehicle display

• DEF, fuel, or electrical supply issues affecting heater operation

Fluid or smoke problems

• Coolant or fuel leaks near the heater

• White or black smoke from the exhaust (if fuel is burned for heating)