Marine diesel heater for quiet, dry cabin warmth on every crossing
Stay comfortable and condensation-free with steady, fuel-sipping heat built for open water. The Espar Airtronic M3 D4L 12V delivers up to 13,600 BTU (4.0 kW) and pairs with the EasyStart Pro controller for precise temperature control and scheduling.
Benefits & Use Cases
This compact Espar marine heater warms cabins fast while keeping humidity down—ideal for overnighting, shoulder-season cruising, and protecting electronics from damp air. Designed for reliable starts and smooth output in changing conditions, it’s a great fit for coastal hops and extended passagemaking alike.
- Fast, even heat with high airflow for multi-cabin boats
- Dry, comfortable interior—reduces condensation and odors
- 12V diesel operation for efficient, independent heating underway or at anchor
- EasyStart Pro: set-and-forget timers, diagnostics, and fine temperature control
Technical
- Fuel: Diesel
- Voltage: 12V
- Heat Output: 13,600 BTU / 4.0 kW
- Max Operating Altitude: 5,500 m (18,000 ft)
- Warranty: 2 years
- Dimensions (heater body): 376 × 140 × 150 mm (14.8 × 5.5 × 5.9 in)
- Heater Part Number: 252955050000
- Installation Kit PN (universal Ø75/90): 252720800000
Vehicle Compatibility
- Motor yachts: ~19–29 ft
- Sailing yachts: ~26–36 ft
Kit Includes
- Espar Airtronic M3 D4L Diesel 12V heater
- Fuel metering pump (12v)
- EasyStart Pro Controller
- Additionally included: Pro controller extension included 9.8 ft/ 3m
- Marine Grade Fuel line - ISO7840 - 19.7 ft / 6 m
- Fuel tank standpipe
- Air Intake Silencer / Muffler
- Electrical harnesses - Plug n' Play
- Marine Grade exhaust system with silencer - approx. 6.6 ft / 2m!
- L-shaped exhaust adapter with a drain for condensation drip
- Aluminum sheet for floor protection
- Hull skin fitting
- Combustion intake pipe ~3.3ft / 1 meter
- Inlet / Outlet grills
- Additionally included: L-shaped marine grade mounting bracket
- Air outlet grill (90 mm. diameter)
- Screws, clips, and plastic straps are required for installation
- Installation manual CD (Scan QR code for installation manual download)
2 outlet options will have additionally:
- 2 meters of 75mm hot air tubing
- 3 meters of 90mm hot air tubing
- 1 x 90mm "Y" tube branch connection
- 1 x 75mm to 90mm hot air tube reducer
- 1 x 75mm hot air outlet
- 1 x 90mm hot air outlet
3 outlet options will have additionally:
- 4 meters of 75mm hot air tubing
- 3 meters of 90mm hot air tubing
- 2 x 90mm "Y" tube branch connection
- 2 x 75mm to 90mm hot air tube reducer
- 2 x 75mm hot air outlet
- 1 x 90mm hot air outlet
Technical Specifications of the Espar Airtronic M3 D4L Diesel 12V Marine Heater kit with EasyStart Pro Controller
- Fuel:
- Diesel
- Voltage:
- 12V
- Max. Heat Output:
- 13,650 BTU (4 kW)
- Number of Outlets:
- 2
- Fuel consumption:
- 0.02 - 0.13 gal/h (0.11 - 0.51 l/h)
- Heater model:
- Airtronic M3
- Max. Altitude:
- 9,900 ft (3,000 m)
Included in the kit:
Marine diesel heater for quiet, dry cabin warmth on every crossing
Stay comfortable and condensation-free with steady, fuel-sipping heat built for open water. The Espar Airtronic M3 D4L 12V delivers up to 13,600 BTU (4.0 kW) and pairs with the EasyStart Pro controller for precise temperature control and scheduling.
Benefits & Use Cases
This compact Espar marine heater warms cabins fast while keeping humidity down—ideal for overnighting, shoulder-season cruising, and protecting electronics from damp air. Designed for reliable starts and smooth output in changing conditions, it’s a great fit for coastal hops and extended passagemaking alike.
- Fast, even heat with high airflow for multi-cabin boats
- Dry, comfortable interior—reduces condensation and odors
- 12V diesel operation for efficient, independent heating underway or at anchor
- EasyStart Pro: set-and-forget timers, diagnostics, and fine temperature control
Technical
- Fuel: Diesel
- Voltage: 12V
- Heat Output: 13,600 BTU / 4.0 kW
- Max Operating Altitude: 5,500 m (18,000 ft)
- Warranty: 2 years
- Dimensions (heater body): 376 × 140 × 150 mm (14.8 × 5.5 × 5.9 in)
- Heater Part Number: 252955050000
- Installation Kit PN (universal Ø75/90): 252720800000
Vehicle Compatibility
- Motor yachts: ~19–29 ft
- Sailing yachts: ~26–36 ft
Kit Includes
- Espar Airtronic M3 D4L Diesel 12V heater
- Fuel metering pump (12v)
- EasyStart Pro Controller
- Additionally included: Pro controller extension included 9.8 ft/ 3m
- Marine Grade Fuel line - ISO7840 - 19.7 ft / 6 m
- Fuel tank standpipe
- Air Intake Silencer / Muffler
- Electrical harnesses - Plug n' Play
- Marine Grade exhaust system with silencer - approx. 6.6 ft / 2m!
- L-shaped exhaust adapter with a drain for condensation drip
- Aluminum sheet for floor protection
- Hull skin fitting
- Combustion intake pipe ~3.3ft / 1 meter
- Inlet / Outlet grills
- Additionally included: L-shaped marine grade mounting bracket
- Air outlet grill (90 mm. diameter)
- Screws, clips, and plastic straps are required for installation
- Installation manual CD (Scan QR code for installation manual download)
2 outlet options will have additionally:
- 2 meters of 75mm hot air tubing
- 3 meters of 90mm hot air tubing
- 1 x 90mm "Y" tube branch connection
- 1 x 75mm to 90mm hot air tube reducer
- 1 x 75mm hot air outlet
- 1 x 90mm hot air outlet
3 outlet options will have additionally:
- 4 meters of 75mm hot air tubing
- 3 meters of 90mm hot air tubing
- 2 x 90mm "Y" tube branch connection
- 2 x 75mm to 90mm hot air tube reducer
- 2 x 75mm hot air outlet
- 1 x 90mm hot air outlet
Choosing Guide
Option Choosing Guide for this product is coming soon, please contact [email protected] 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
