The Autoterm range (formerly known as Planar) has established itself as a leading provider of high-quality yet affordable diesel heating solutions for the marine industry. These heaters are engineered to withstand extreme sub-zero temperatures, making them exceptionally reliable for year-round cruising and narrowboat habitation.
Expertise and OFTEC-Trained Installation
Proper installation of a diesel heater is critical for both longevity and safety, particularly regarding exhaust routing and fuel line integrity. At Marine Heating Solutions, our OFTEC-trained engineers specialise in Autoterm diesel heater installations, ensuring every system meets Boat Safety Scheme (BSS) standards.
We provide a Boat Diesel & Oil Appliance Certificate with every installation, providing documented proof of a safe and compliant setup. For official technical documentation and software updates, you can access the Autoterm Global Support Center or consult the OFTEC guide for liquid fuel appliances.
Autoterm Liquid Heaters: Hydronic Warmth
For vessels utilising radiator systems or matrix blowers, the Autoterm Flow series (Flow 5 and Flow 14) provides powerful hydronic heating. These liquid heaters circulate warm coolant through a closed-loop system, which can also be used to pre-heat an engine or provide domestic hot water via a calorifier. The Flow 14 is specifically designed for larger marine applications, ensuring consistent warmth across extensive pipework runs.

Autoterm Flow 5: A compact 5kW hydronic (water) heater designed to pre-heat boat engines and provide domestic hot water and radiator heating.

Autoterm Flow 14: A powerful 14kW water heater suited for larger vessels, capable of supporting extensive radiator circuits and high hot water demands.
Autoterm Air Heaters: Robust Forced-Air Solutions
Autoterm’s air heater lineup—including the 2D (2kW), 4D (4kW), and 9D (8kW) models—provides rapid, dry heat for vessels of all sizes. These units are prized for their low fuel consumption and minimal noise levels, featuring a brushless motor and a “super quiet” fuel pump as standard.
- Autoterm 2D: Ideal for small to medium cabins, offering efficient heating with a compact footprint.
- Autoterm 4D: A versatile choice for larger saloon areas or multi-cabin narrowboats.
- Autoterm 9D: Designed for significant commercial or large leisure vessels requiring high-volume air movement.
Each heater is fully EN-certified and can be paired with advanced controllers like the Autoterm Comfort Controller, which features a user-friendly digital interface and programmable timers. For remote management, the QSTART modem allows users to activate their heating via a smartphone app—perfect for pre-warming a boat before arrival.

Autoterm Air 2D: The most popular 2kW diesel air heater. Efficient, quiet, and perfect for heating standard cabin spaces in small to medium boats.

Autoterm Air 4D: A high-output 4kW air heater designed for larger interior volumes, providing rapid warmth for bigger galleys and multi-cabin layouts.

Autoterm Air 9D: A heavy-duty 8kW/9kW air heater for large commercial vessels or luxury yachts requiring maximum thermal performance.
Autoterm Controllers
Autoterm controllers offer advanced options for managing the heating systems of your boat with precision and convenience. Designed for seamless integration with Autoterm diesel heaters, these controllers feature user-friendly interfaces and programmable settings that allow for easy temperature adjustments and monitoring.

Autoterm Comfort Controller: The latest digital interface featuring temperature sensors, timers, and specialized ‘High Altitude’ and ‘Ventilation’ modes.

Autoterm QStart Modem: An LTE modem that allows you to control your Autoterm heater remotely via a smartphone app—ideal for pre-warming your boat.


