Efficient Espar diesel coolant heater for vehicles, equipment, and off-grid use
The Espar Hydronic D4WSC 12V diesel coolant heater is a first-generation, fuel-powered water heater delivering 13,650 BTU (4 kW) of reliable heating power. Designed for passenger cars, vans, trucks, and off-grid vehicles, it warms the cabin, preheats the engine, and even defrosts windows for safe and comfortable operation in cold weather. Its compact design - with an integrated water pump and fuel metering pump - simplifies installation and reduces setup time.
Benefits & Use Cases
This Eberspächer Hydronic D4WSC diesel coolant heater is ideal for anyone needing efficient engine preheating and cabin comfort without idling the motor. Its self-contained design makes it perfect for passenger vehicles, transporters, off-grid campers, and industrial or marine applications.
- Preheats engine and interior for quick, frost-free starts
- De-ices and defrosts vehicle windows in minutes
- Integrated water and fuel pumps simplify installation
- Low fuel and power consumption for off-grid efficiency
- Compact and quiet operation for daily and overnight use
Technical Specifications
- Fuel Type: Diesel
- Voltage:12 V
- Max Heat Output: 13,650 BTU (4 kW)
- Fuel Consumption: 0.05 - 0.18 gal/h (0.2 - 0.69 L/h)
- Power Consumption: 22 - 50 W (120 W at startup)
- Max Operating Altitude:5,000 ft (1,500 m)
- Warranty: 2 Years
- Dimensions (Heater body only): 8.7 × 3.6 × 6.3 in (222 × 91 × 160 mm)
- Part Numbers: 252257050000 / 25.2257.05.0000 / 25 2257 05 00 00
- Certifications: CE, E-Mark
Vehicle Compatibility
- Passenger cars and light commercial transporters
- Mercedes-Benz Sprinter, VW Crafter, Ford Transit, and Ram ProMaster vans
- Truck sleeper cabs and heavy-duty transport vehicles
- Marine cabins and small boats (with proper ventilation)
- Off-grid RVs, expedition rigs, and construction machinery
Kit Includes
- Espar / Eberspächer Hydronic D4WSC Heater 12 V
- Installation manual CD
- Warranty documentation
Manuals
Technical Specifications of the Espar Hydronic D4WSC Diesel 12V Heater
- Part Number:
- 252257050000 / 25.2257.05.0000 / 25.2257.05.00.00 25 2257 05 0000 / 25 2257 05 00 00
- Fuel:
- Diesel
- Voltage:
- 12V
- Max. Heat Output:
- 13,650 BTU (4 kW)
- Fuel consumption:
- 0.05 - 0.18 gal/h (0.2 - 0.69 l/h)
- Heater model:
- Hydronic D4WSC
- Max. Altitude:
- 5,000 ft (1,500 m)
Included in the kit:
Efficient Espar diesel coolant heater for vehicles, equipment, and off-grid use
The Espar Hydronic D4WSC 12V diesel coolant heater is a first-generation, fuel-powered water heater delivering 13,650 BTU (4 kW) of reliable heating power. Designed for passenger cars, vans, trucks, and off-grid vehicles, it warms the cabin, preheats the engine, and even defrosts windows for safe and comfortable operation in cold weather. Its compact design - with an integrated water pump and fuel metering pump - simplifies installation and reduces setup time.
Benefits & Use Cases
This Eberspächer Hydronic D4WSC diesel coolant heater is ideal for anyone needing efficient engine preheating and cabin comfort without idling the motor. Its self-contained design makes it perfect for passenger vehicles, transporters, off-grid campers, and industrial or marine applications.
- Preheats engine and interior for quick, frost-free starts
- De-ices and defrosts vehicle windows in minutes
- Integrated water and fuel pumps simplify installation
- Low fuel and power consumption for off-grid efficiency
- Compact and quiet operation for daily and overnight use
Technical Specifications
- Fuel Type: Diesel
- Voltage:12 V
- Max Heat Output: 13,650 BTU (4 kW)
- Fuel Consumption: 0.05 - 0.18 gal/h (0.2 - 0.69 L/h)
- Power Consumption: 22 - 50 W (120 W at startup)
- Max Operating Altitude:5,000 ft (1,500 m)
- Warranty: 2 Years
- Dimensions (Heater body only): 8.7 × 3.6 × 6.3 in (222 × 91 × 160 mm)
- Part Numbers: 252257050000 / 25.2257.05.0000 / 25 2257 05 00 00
- Certifications: CE, E-Mark
Vehicle Compatibility
- Passenger cars and light commercial transporters
- Mercedes-Benz Sprinter, VW Crafter, Ford Transit, and Ram ProMaster vans
- Truck sleeper cabs and heavy-duty transport vehicles
- Marine cabins and small boats (with proper ventilation)
- Off-grid RVs, expedition rigs, and construction machinery
Kit Includes
- Espar / Eberspächer Hydronic D4WSC Heater 12 V
- Installation manual CD
- Warranty documentation
Manuals
Choosing Guide
Option Choosing Guide for this product is coming soon, please contact support@heatso.com if you need help picking the right options or have any questions.
Shipping
- United States - 1-5 Working Days
- United Kingdom - 2-5 Working Days
- European Union - 2-7 Working Days
- Australia / New Zealand - 5-14 Working Days
- Rest of World - 5-14 Working Days
There may be a delay if the order is shipped to a PO or parcel shop address. Please note, some couriers do not offer shipping to PO boxes.
View full shipping & Delivery information
Returns
You can return or exchange goods within 14 days from the date of purchase if the item is unused and brand new in unopened packaging. You must contact us before returning any goods, though. Additional deductions might be applied as indicated in the Returns section of our Terms and Conditions.
Warranty Information
Most heaters come with 2 year warranty + optional 1 year extended Warranty available
- Parts - 1 Year Warranty
- Refrigerators - 2 Year Warranty
- AC Systems - 1 Year Warranty
- Heavy duty heating equipment (10 kW+) - 1 Year Warranty
- Other items - 1 Year Warranty
Installation, servicing and maintenance must be done in accordance with manufacturers guidelines. Failure to follow these guidelines will result in voiding your warranty.
We provide free technical and installation support via email or phone to all of our customers who purchase a heater, heater kit or other products from Heatso. We take pride in our customer service and want to ensure that your heater system is properly installed. As a result, if you have any difficulties, please do not hesitate to contact us.
If you require removing and/or refitting your item, please visit a local professional or authorized specialist, if you can not find one you can contact us and we will try to recommend a local partner to assist with the task. The cost of removing and/or refitting this item is not covered by the warranty.
Customer reviews
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stock
Not even open the box, was bought as a back unit for one already installed and rebuilt a few months ago.
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D4WSC
The new unit would not fit the 2003 base. Had to modify things. Would have nice if that possibility had been brought up when I bought the replacement unit
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perfect for my truck
shipping very fast