

1. Select Your Heater.
2. Select Your Controller.
3. Choose Your Ducting and Outlets by visiting the "Heater Installation Accessories" or click here.
The Eberspächer Airtronic D4L is the standard 4.0 kW diesel air heater, designed for the majority of vehicle and marine heating installations.
It provides efficient, reliable heating with lower electrical current draw, making it ideal for installations where airflow demands are moderate and battery capacity is more limited.
The D4L is best suited to applications where:
Ducting runs are short to medium length
There are fewer air outlets
Lower electrical power consumption is important
Quiet, efficient operation is preferred
Although it uses a standard airflow fan, the D4L produces the same 4.0 kW heat output as the higher-airflow D4R. It is simply optimised for typical, less demanding duct layouts.
Standard airflow configuration
Lower electrical current draw compared to the D4R
Same 4.0 kW heat output as the D4R
Optimised for standard ducting and outlet layouts
Quiet, efficient and proven performance
Marine Base Kit – 4.0 kW Diesel
The Eberspächer Airtronic AM3 D4L is a second-generation diesel air heater engineered for high efficiency, long service life, and modern vehicle integration.
This programmable heater operates independently of engine heat, making it suitable for campervans, motorhomes, commercial vehicles, and marine installations.
It is approved for installation inside passenger compartments and near hazardous materials, with adjustable heat output from 1.05 kW to 4.0 kW.
Automatic altitude adjustment as standard, up to 5,500 metres
Brushless motor for extended service life of up to 5,000 hours
Integrated CAN bus technology for modern vehicle systems
Acoustically improved metering pump for quieter operation
Optimised combustion process for reduced emissions and improved efficiency
Electrical consumption:
0.5 – 3.08 Amps
Hot air throughput without backpressure:
40 – 185 kg/h
This is a genuine Eberspächer product supplied with a 36-month manufacturer’s warranty.
Airtronic M3 Recreational D4L diesel heater
Selectable controller
Complete electrical harnesses and connections
Marine-grade stainless steel mounting bracket
90 / 75 mm hood (if selected)
1 metre combustion air intake pipe
25 mm ID combustion air intake silencer
2 metre marine exhaust silencer (24 mm ID)
Stainless steel hull skin fitting (24 mm)
Fuel T-piece
Air intake entry grille
All required clips and fixings
Marine standpipe
Installation manual on CD
6 metres of ISO 7840 marine fuel hose
Eberspächer 36-month warranty handbook
Replacement heater
Marine use
Campervans and motorhomes
Commercial and utility vehicles
Bespoke kits can be built to order to suit your installation requirements.
If you require additional 60 mm ID ducting or accessories, please contact our sales team or visit the Heater Installation Accessories tab above and we will be happy to assist.
Warranty Terms
Mellor Solutions Ltd trading as Mellor Online is an authorised distributor of heating parts and heater kits for the vehicle and marine markets.
Warranty Coverage:
Additional Services:
Returning a Heater:
Customer Responsibilities:
Exclusions and Important Notes:
Returns Policy
Our returns policy applies to consumer purchases only (not business or trade orders).
Our returns policy does not cover items that fall under manufacturer warranties. If you believe your item is eligible for warranty service or you wish to return an item for a refund, please contact our support team or email us at sales@melloronline.co.uk.
Refunds and Cancellation Rights
You have the right to cancel your order within a 14-day cooling-off period, starting the day after you receive your items. Refund requests can be submitted within 30 days of the invoice date. Refunds will be processed within 14 days of receiving the returned goods.
Notification of Intent to Cancel
To cancel an order or request a refund under the UK Consumer Contracts Regulations 2013, you must inform Mellor Solutions Ltd trading as Mellor Online of your intention by phone, email, WhatsApp, or post within the applicable period. This is 14 days for cancellations and 30 days for refunds.
Upon receiving your request, we will send you a confirmation and authorization to return the goods. Please include your original invoice number with your return. All items must be in a resaleable condition
Upon receiving your request, we will send you a confirmation and authorization to return the goods. Please include your original invoice number with your return. All items must be in a resaleable condition.
Return Shipping
You are responsible for returning goods using an insured and trackable shipping method at your expense. We will only consider refund requests if there is proof of delivery to Mellor Solutions Ltd trading as Mellor Online from your chosen courier. Once we receive the goods, we will issue a full refund minus any delivery charges.
If you cannot arrange a return, please contact us. We can arrange collection for you, but a fee will apply, which will be deducted from your refund.
Please note that delivery charges from the original purchase are non-refundable, as the service is completed once the order is placed.
Processed and Dispatched Orders
Orders that have already been processed or dispatched cannot be canceled; however, they can be returned for a refund once received by the customer.
We strive to facilitate a prompt refund process upon receiving returned items.
Return Address
FAO: RETURNS
Mellor Online
139 Manor Road
Ossett
West Yorkshire
WF5 0LQ
United Kingdom
Specific Terms
Your Statutory Rights
Your statutory rights are unaffected by the above terms. Consumers, excluding business trade customers, are further protected under the UK Consumer Contracts Regulations 2013.
For any questions, please contact our support department before returning any items.
Shipping Information: UK & Worldwide
UK Delivery:
International Delivery:
| Technical Description (PDF) |
| Repair Manual (PDF) |
| Download PDF 3 |
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