Webasto Air Top Evo 40

ualified Boat Safety Scheme (BSS) examiner for inland waterway vessel inspections
Gas Safe Registered engineer for marine LPG gas installations and safety certificates
OFTEC certified technician for marine diesel heating and oil-fired appliance servicing


The Webasto Air Top Evo 40 is a high-capacity diesel air heater engineered for larger boats up to 45 feet. It represents a significant step up in power and sophistication from the 2000 STC model, making it the preferred choice for owners of medium-to-large yachts and narrowboats who require rapid heating and precise climate control.

Webasto Air Top Evo 40: Powerful and Intelligent Heating

The Air Top Evo 40 delivers a formidable 4kW of heat output while maintaining impressive fuel efficiency. It features intelligent blower control and a multi-mode operation system, allowing the heater to adjust its performance based on the specific needs of the cabin. This results in ultra-quiet operation and a highly stable interior temperature. The Evo 40 is also equipped with an automatic altitude adjustment feature, ensuring reliable performance across various geographic conditions.

A standout feature is the included Webasto MultiControl digital interface, which allows users to program heating schedules, adjust fan speeds, and toggle between heating, ventilation, and “boost” modes with ease.

Expert Installation and BSS Safety

Our OFTEC-trained engineers provide professional Webasto Air Top Evo 40 installations, utilising high-quality marine-grade components. This includes a room-sealed exhaust system and a stainless steel through-hull skin fitting to ensure full compliance with Boat Safety Scheme (BSS) standards. For additional technical resources, you can consult the Webasto Corporate Technical Portal and the OFTEC consumer guide.


Webasto Air Top Evo 40 marine diesel air heater unit showing the air intake and exhaust ports.
The compact and powerful Webasto Air Top Evo 40 diesel heater unit.

Webasto Air Top Evo 40 Narrowboat Kit Includes:

Webasto Air Top 4 kW Diesel Heater – 12 Volt
Fuel Pump
Webasto Controller with Timer
Fuel Pick-up Pipe
Electrical harness c/w fuse holders and fuses
1m Exhaust Pipe

Optional extras:

Webasto Room Thermostat

Webasto ThermoConnect TCON 2 

2m Marine Exhaust Pipe

24mm Exhaust Skin Fitting / Hull Fitting

Marine Fuel Filter With Stop Tap

Ducting and Vents

Diesel Appliance Safety Certificate


Get A Quote:

Installation Only

You source the appliance online to get the best market price, and we provide the expert, certified installation.

Full-Service Package

Want us to handle absolutely everything from sourcing to fitting?