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 D5E 12V heater with mounting bracket
- EasyStart Pro Timer controller
- Coolant pump with mounting bracket
- Fuel metering pump with mounting accessories
- Wiring harness
- Coolant pump harness
- Water connection sockets (x2)
- Fuel Standpipe and fuel line
- Silencer / muffler with Z shape bracket
- Exhaust Hose - 900 mm / 35.4 in and 300 mm / 11.8 in with end cap
- Coolant hose
- Air intake silencer - 760 mm / 29.9 in
- Mounting accessories - cable ties, clamps, screws, etc.
Manuals
Technical Specifications of the Espar Hydronic S3 D5E CS Diesel 12V Water Heater kit with EasyStart Pro Controller
- Part Number:
- 252934050000 / 252993050000 25 2934 05 0000 / 25.2934.05.0000 / 25 2993 05 0000 / 25.2993.05.0000 25 2934 05 00 00 / 25.2934.05.00.00 / 25 2993 05 00 00 / 25.2993.05.00.00
- Fuel:
- Diesel
- Voltage:
- 12V
- Max. 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
- Dimensions (L x W x H):
- 8.4 x 3.5 x 5.6 in (215 x 91 x 144 mm)
- Weight:
- 4.4 lb (2 kg)
- Heater model:
- Hydronic S3
- Max. Altitude:
- 9,900 ft (3,000 m)
Included in the kit:
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 D5E 12V heater with mounting bracket
- EasyStart Pro Timer controller
- Coolant pump with mounting bracket
- Fuel metering pump with mounting accessories
- Wiring harness
- Coolant pump harness
- Water connection sockets (x2)
- Fuel Standpipe and fuel line
- Silencer / muffler with Z shape bracket
- Exhaust Hose - 900 mm / 35.4 in and 300 mm / 11.8 in with end cap
- Coolant hose
- Air intake silencer - 760 mm / 29.9 in
- Mounting accessories - cable ties, clamps, screws, etc.
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
Write a Review
Espar Hydronic S3 D5E CS Diesel 12V Water Heater kit with EasyStart Pro Controller
-
easy instal
This is the latest model I believe and it is super easy to install. No cable crimping - thank good. Super quiet also
-
Recommended
Everything as described in description. Though, I still had few questions and got in touch with Heatso. They were very professional and helpful. After talking with them I was confident in my purchase. Recommended!