Espar Hydronic S3 D5E CS Diesel 12V Water Heater kit with EasyStart Pro Controller

Hydronic engine preheater for faster cold starts & cabin comfort

Warm your engine and cabin efficiently with this compact espar hydronic heater. The Hydronic S3 D5E delivers steady 17,000 BTU (5 kW) diesel heating and pairs with the EasyStart Pro timer for precise schedules and diagnostics - perfect for winter reliability and off-grid use.

Benefits & Use Cases - espar coolant heater

Cut idling, reduce engine wear, and enjoy quiet hydronic warmth. Ideal as an espar engine heater for cold-start protection in passenger vehicles and commercial fleets, and as a compact boiler for RV water/air heat exchangers.

• Engine-off preheating for faster starts and lower emissions.
• Stable coolant loop heat for fan-coil or heat-exchanger cabin heating.
• EasyStart Pro controller adds timer programs and service prompts.
• Efficient diesel operation for long runtime with minimal fuel use.

Technical

• Fuel: Diesel
• Voltage: 12V
• Heat output: 17,000 BTU (5 kW)
• Fuel consumption: 0.03 - 0.15 gal/h (0.15–0.59 L/h)
• Power consumption: 5 - 32 W
• Max operating altitude: 9,900 ft (3,000 m)
• Heater body dimensions: 8.4 × 3.5 × 5.6 in (215 × 91 × 144 mm)
• Part numbers: 252934050000 / 252993050000 (also referenced as 25 2934 05 0000 / 25.2934.05.0000 / 25 2993 05 0000 / 25.2993.05.0000 and variants)
• Certifications: ECE-R122 (heater), ECE-R10 (EMC), type-approval marks 122R-000449; 10R-047330
• Warranty: 2 years

Vehicle Compatibility

• Cab and engine heater
• Passenger cars (from 2.0 L displacement)
• Emergency vehicles
• Vans, large taxis, minivans
• Commercial vehicles (incl. tandem configs with air heaters)
• Construction & agricultural machines
• Motor yachts up to ~25 ft
• Motor homes

Kit Includes

• Hydronic S3 D5E CS 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 (Silencers 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.

Manuals

• Technical Documentation
• Repair Instructions
• Spare Parts List