Gasoline water heater for faster warm-ups and clear windows
Enjoy quick cabin comfort and reliable engine pre-heat with a compact 5 kW (17,000 BTU) gasoline water heater. The Espar Hydronic S3 B5E CS pairs with the EasyStart Pro controller for precise scheduling and effortless control.
Benefits & Use Cases
The Hydronic S3 B5E circulates heated coolant to warm your engine and HVAC core, delivering rapid defrost, easier cold starts, and reduced engine wear. Its compact body fits tight engine bays; separate fuel metering and coolant pumps simplify flexible mounting.
- Pre-heat engine and cabin for comfort and longevity
- Fast defrost/de-ice to keep visibility clear
- Programmable comfort via EasyStart Pro timer controller
- Ideal for daily drivers, emergency fleets, vans, and motorhomes
- Can support domestic hot water loops in boats and RVs
Technical Specifications
- 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)
- Weight: 4.4 lb (2 kg)
- Part numbers (heater): 202008050000 / 202051050000 / 20.2008.05.0000 / 20.2051.05.0000
Browse Eberspächer/Espar Manuals & Technical Documentation
Vehicle Compatibility
- 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)
Kit Includes
- Hydronic B5E 12V heater with mounting bracket
- EasyStart Pro Timer controller with extension and adapter
- Coolant pump with mounting bracket
- Fuel metering pump with mounting accessories
- Wiring harness
- Coolant pump harness
- Water connection sockets (x4)
- Fuel line
- Exhaust Hose - 900 mm / 35.4 and end cap
- Section of a coolant hose
- Mounting accessories - cable ties, clamps, screws, etc.
Optional accessories - RECOMMENDED
The optional accessory kit includes an intake silencer, exhaust silencer, and Z-shaped bracket with clamp — ideal for customers wanting a quieter, cleaner, and more professional heater installation. The silencers help reduce both intake and exhaust operating noise, improving comfort in enclosed spaces such as vehicles, cabins, or work equipment, while the bracket and clamp provide secure mounting, better routing, and added protection against vibration during operation.