Truma Combi D4E 4kW Diesel & Electric Air and Water Heater
Compact. Powerful. Energy Efficient.
Perfect for small to medium campervans, motorhomes, and RVs
The Truma Combi D4E is a 4kW combination air and water heater that delivers powerful, energy-efficient performance in a compact, lightweight design. Ideal for small to medium campervans, this all-in-one unit provides fast and even interior heating and hot water on demand—without needing a separate water boiler.
Core Features
- Dual fuel operation – Run on diesel, electric (230V), or mixed mode
- Built-in 10L water tank – Heats water and air simultaneously
- Space-saving design – No separate water heater needed
- Quiet performance – Minimal noise, ideal for peaceful nights
Performance Benefits
- Four air outlets – Ensures optimal heat distribution
- Energy efficient – Low power consumption, even in electric mode
- Year-round use – Can operate with empty water tank
- Rapid heating – Hot water ready in just 20 minutes
🌐 Truma iNet X Smart Operating System
The Truma iNet X System is Truma's comprehensive smart operating system that transforms how you control your vehicle's comfort systems. This complete system comprises the iNet X Panel with 4.3" touchscreen, the free smartphone app, and optional iNet X Connect for remote operation - providing intuitive control and maximum comfort that sets Truma apart.
Central control unit
One intuitive display controls your entire comfort system - heating, hot water, and diagnostics combined
Intuitive operation
Simple touch controls make complex heating functions feel effortless
Mobile networked
Can even be controlled on the move
What's Included in Your Kit
Truma Combi D4E Unit
Complete diesel / 230V electric combination heater with integrated 10L water tank
iNet X Digital Control Panel
4.3" touchscreen control panel for intuitive operation and system monitoring
Water Connections
John Guest 12mm push-fit connections for reliable, leak-free water system integration
Truma Combi Cowling
External cowling in sleek black finish for professional exterior installation
Additional Items for Complete Installation
For new installations, you'll also need:
- Blown air ducting (65mm) for heat distribution
- Heater outlet vents (4 recommended for optimal heat flow)
- Diesel connection kit if not already installed
Our expert team can help you select the right accessories for your specific vehicle.
Call: 01271 611 015
Flexible Heating Options
Technical Specifications
| Specification | Value |
|---|---|
| Energy sources | Diesel + electricity |
| Rated heat output in diesel mode | 1800 W / 2500 W / 4000 W |
| Rated heat output in electric mode | 900 W / 1800 W |
| Rated heat output in mixed mode | max. 4900 W |
| Fuel consumption | 0.18 – 0.45 l/h |
| Power consumption (at 12 V): operation | max. 5.5 A for short periods (average approx. 1.2 A) |
| Power consumption (at 12 V): water heating | max. 0.4 A |
| Power consumption (at 230 V) | 3.9 A / 7.8 A |
| Air flow rate (4 outlets) | max. 250 m³/h |
| Water capacity | 10 litres |
| Heating time: Water only (15°C to 60°C) | approx. 20 minutes |
| Heating time: Water + Air (15°C to 60°C) | approx. 70 minutes |
| Weight | approx. 15.0 kg |
| Dimensions (L x W x H) | 510 x 450 x 300 mm |
| Installation dimensions | 540 x 500 x 350 mm (min.) |
Frequently Asked Questions
Installation & Compatibility
While technically possible for experienced DIYers, we strongly recommend professional installation due to diesel and electrical connections. Installation typically takes 6-8 hours for a qualified technician.
The unit requires a minimum installation space of 540 x 500 x 350mm. It's specifically designed for small to medium campervans and motorhomes. Contact us with your vehicle details for specific compatibility.
Yes, the Combi D4E can replace a Combi 4, with the same mounting points and similar dimensions. You may need to add diesel fuel connections if upgrading from a gas-only model.
Operation & Performance
Water heats from 15°C to 60°C in approximately 20 minutes (water only) or 70 minutes when heating both water and air.
Yes! The Combi D4E operates on 230V electric (900W/1800W), diesel, or both combined for maximum 4900W output.
Fuel consumption ranges from 0.18-0.45 l/h depending on heat setting. This translates to excellent efficiency - roughly 45-110 hours of heating from a 20L diesel tank.
Absolutely! The D4E is specifically designed for small to medium campervans. Its 4kW output provides efficient heating without oversizing for compact spaces.
iNet X System
iNet X is Truma's smart control system included with this kit. It provides touchscreen control and optional smartphone app control.
Yes, the Truma D4E can be controlled from your phone using the free Truma app in two ways:
Bluetooth Control (included): Control your heating and hot water directly via Bluetooth when you're nearby - perfect for adjusting settings from the front cab without having to access the physical control panel. This built-in feature works within standard Bluetooth range (typically 30-50 feet).
Remote Control (optional): For control from anywhere with internet access - such as pre-heating before you arrive at your campervan - you'll need the optional iNet X Connect module (sold separately). This allows you to monitor and control your system remotely via Wi-Fi/mobile data connection.
Maintenance & Warranty
Truma products come with a 2-year manufacturer warranty from date of purchase, extended to 3 years with annual servicing.
Absolutely! The Combi D4E is designed for year-round use. The optional FrostControl prevents freezing, and it operates efficiently even in cold weather.
Customer Reviews
Thank you fot great service, and excellent price, Product is very good quality as expected from Truma.
As we discussed, the item has arrived on a pallet absolutely battered, I’ve opened it and inside it all looks in one piece but was scattered all over the box with smashed the packaging. I will be unable to check it fully for another couple of months.
Truma has designed the 6E to be relatively quiet, which is a big plus if you're sleeping close to the unit. Fan noise is minimal on lower settings.
It's one of the best all-in-one heating solutions currently available for campervans and motorhomes.