Truma Combi D4E diesel heater for motorhomes, campervans and caravans: diesel on the road and a 230 V mains hook-up on the campsite
The Truma Combi D4E diesel heater is the version of the Combi D4 with electric heating rods: it burns diesel when you travel and plugs into a 230 V mains hook-up when you park on a campsite. It also works as a combi boiler, with a built-in 10-litre water heater, and, as Truma puts it, quickly heats small and medium-sized vehicles.
You decide how to heat. Diesel mode is for stand-alone use, while electric mode is for stationary use and combined mode goes up to a maximum of 3.9 kW. Truma suggests electric mode in the shoulder season, diesel on cold days and combined mode when it is extremely cold. According to the brand, hybrid mode also heats faster.
This Truma Combi D4E is a next-generation model and comes with the iNet X Panel 2. Only a qualified technician can fit it. The box does not include the exhaust system, the water connection set with FrostControl or the tank connection kit, so it pays to plan the whole installation before you buy. If you want to see more from the brand, browse the Truma products in our shop.
Benefits of the Truma Combi D4E diesel heater
- Two energy sources in one unit: the diesel in the vehicle's tank for travelling and the campsite's 230 V mains hook-up for when you park.
- Three operating modes, diesel, electric and combined, selected from the control panel.
- In combined mode, electricity takes priority and the burner only comes on when you need more power, up to 3.9 kW.
- If the 230 V supply fails in combined mode, the control panel warns you and the unit switches to diesel operation by itself.
- You set the electric power at 900 W or 1800 W, depending on the campsite's fuse protection.
- According to Truma, the built-in heating rods shorten the heat-up time with hybrid heating.
- Truma permits diesel operation while driving, with EN 590 diesel or HVO to EN 15940.
- Built-in 10-litre water heater, which runs on diesel or electricity.
- 4.3" capacitive touchscreen on the iNet X Panel 2 and control from your mobile phone with the iNet X App.
Is it compatible with your motorhome, campervan or caravan?
Because Truma has designed it only for installation in motorhomes of vehicle class M1 and in caravans (trailers) of class O, a campervan needs motorhome approval, while a commercial vehicle (class N) does not qualify. The table also lists the requirements Truma publishes, including those on the electrical side.
| Requirement | What Truma says |
| Approved vehicles | Motorhomes of class M1 and caravans (trailers) of class O. |
| Prohibited uses | Coaches and buses (M2 and M3), commercial vehicles (class N), boats and other watercraft, hunting or forestry huts, weekend homes, canopies, and trailers or vehicles for dangerous goods. |
| Vehicle size | Small and medium-sized; Truma recommends the Combi D6 (E) for large ones. |
| Mains hook-up | Check that the campsite's fuses can handle the power set on the control panel, and fully unwind the extension cable reel. |
| Fuel | From the vehicle's tank, with the connection kit recommended for each model (see the tables below). |
| Room temperature sensor | External; the vehicle manufacturer determines the sensor position according to the vehicle type. |
| Window switch | Required with the wall cowl below a window that opens or within 30 cm of one (EN 1949). |
| Mains water | Pressure reducer and non-return valve if connected to a mains water supply. |
| Warm-air ducts | Essential: the unit does not work without them. |
As for space, the unit measures 510 x 450 x 300 mm, while Truma requires a minimum installation space of 540 x 500 x 350 mm, plus room for the connections and the drain valve. While the heater is running, keep the wall cowl 1 m or more from walls, buildings, tents and other vehicles.
Tank connection kit for the Truma Combi D4E diesel heater, by vehicle
Because the burner draws its fuel from the vehicle's tank, Truma assigns a connection kit to each model and warns that the list may change or grow. First come the Fiat, Citroën, Peugeot, Iveco and Renault chassis. If you want to know what the numbers in brackets mean, see the notes below.
| Vehicle and tank | Without prepared fuel take-off | With prepared take-off | Prepared take-off already in use (e.g. by an auxiliary heater) |
| Fiat Ducato 250 (1) / Citroën Jumper (1) / Peugeot Boxer (1), 90 l, up to Euro 5 | TAS 01 / 09 | with SAE: no kit, direct connection (4); without SAE: TAS 03 | TAS 10 (3) |
| Fiat Ducato 250 / Citroën Jumper / Peugeot Boxer, 90 l, from Euro 5 | TAS 01 / 09 / 11 | with SAE: no kit, direct connection (4); without SAE: TAS 03 | TAS 10 (3) |
| Fiat Ducato 250 / Citroën Jumper / Peugeot Boxer, 120 l | TAS 01 / 11 | with SAE: no kit, direct connection (4); without SAE: TAS 03 | TAS 10 (3) |
| Iveco Daily, from 2007 (identical with Euro chassis) | TAS 01 | with SAE: no kit, direct connection (4); without SAE: TAS 03 | TAS 06 |
| Renault Master up to 04/2010 | TAS 01 / 09 (2) | without SAE: TAS 03 | TAS 10 (3) |
| Renault Master from 05/2010, 80 / 100 l | TAS 06 (6) | – | TAS 10 (3) |
| Renault Trafic from 2014 | TAS 06 (6) | – | TAS 10 (3) |
If your Ducato already has the tank take-off with an SAE connector, you do not need a kit, because Truma's fuel line, which you order by the metre, will do. For the other vehicles in the tables, however, Truma assigns a specific connection kit.
Tank kit for Ford, Mercedes-Benz, Volkswagen and MAN
The assignment continues here for the Ford Transit, Mercedes-Benz Sprinter, Volkswagen Crafter, T5 and T6, as well as the MAN TGE. In several cases you may have to lower the vehicle's tank, as note (2) states, and the middle column only applies if the vehicle has the prepared fuel take-off.
| Vehicle and tank | Without prepared fuel take-off | With prepared take-off | Prepared take-off already in use (e.g. by an auxiliary heater) |
| Ford Transit, 80 l | – | TAS 05 (5) | TAS 06 |
| Mercedes-Benz Sprinter 906 / 907 (2), 75 l | TAS 01 (2) | TAS 05 (2) | TAS 06 |
| Mercedes-Benz Sprinter 906 / 907 (2), 100 l | TAS 01 (2) | TAS 05 (2) | TAS 06 |
| Volkswagen Crafter up to 2016 (2), 75 l | TAS 01 (2) | TAS 07 (2) | TAS 06 |
| Volkswagen Crafter up to 2016 (2), 100 l | – | TAS 07 (2) | TAS 06 |
| Volkswagen Crafter from 2017 (2), 63 / 75 l | TAS 01 (2) | TAS 07 (2) | TAS 10 (3) |
| Volkswagen T5 | TAS 01 (2) | TAS 07 (2) | TAS 06 |
| Volkswagen T6 | TAS 01 (2) | TAS 07 (2) | TAS 06 |
| MAN TGE | TAS 01 (2) | TAS 07 (2) | TAS 06 |
Truma does not publish any other list of vehicles, so treat this one as a kit recommendation for each model.
Notes and kit codes
These notes complete the rows above, while the codes link each TAS to its part number.
| Note | What Truma says |
| (1) | From Euro chassis. |
| (2) | It may be necessary to lower the vehicle's tank to fit the connection kit. |
| (3) | For connection to fuel lines fitted as standard on the vehicle, Ø 5 x 1.5 mm. |
| (4) | Direct connection of the Truma fuel line to the SAE connector fitted as standard on the vehicle. |
| (5) | If the vehicle has the ‘Camper package’ option (from August 2009). |
| (6) | Approval for fitting to the vehicle's return line covers only the chassis listed; you must fit the kit to that line following Renault's fitting guidelines. |
Each kit also comes with detailed fitting instructions.
| Truma part number | Tank connection kit |
| 34601-01 | TAS 01: you have to remove the level sensor. |
| 34601-03 | TAS 03. |
| 34601-05 | TAS 05. |
| 34601-06 | TAS 06. |
| 34601-07 | TAS 07. |
| 34601-09 | TAS 09: 280 mm pick-up lance; you do not need to remove the level sensor. |
| 34601-10 | TAS 10. |
| 34601-11 | TAS 11: 330 mm pick-up lance; you do not need to remove the level sensor. |
Technical specifications of the Truma Combi D4E diesel heater
The Combi D4E differs from the D4 only in its electrical elements, so most figures are the same, but there are extra figures for electrical power, combined power and 230 V consumption. All figures are those Truma publishes for the next generation.
| Specification | Value |
| Manufacturer and official name | Truma, Combi D 4 E (next generation) |
| Fuel | diesel to EN 590 and diesel to EN 15940 (HVO); it does not accept more than 7% biodiesel |
| Rated heat output on diesel (automatic stages) | 1000 W / 2000 W / 3000 W / 4000 W (max. 4.4 kW) |
| Power in electric mode (230 V) | 900 W / 1800 W |
| Power in combined mode (diesel + electric) | max. 3.9 kW |
| Consumption at 230 V | 3.9 A (900 W) or 7.8 A (1800 W) |
| Fuel consumption | 0.1 – 0.4 l/h (0.1 l/h at an average output of 1000 W) |
| Water capacity | 10 litres |
| Water heating time from approx. 15 °C to approx. 60 °C | hot water only: approx. 24 min (EN 15033); heating and hot water: approx. 80 min |
So electric mode depends on the campsite's fuse protection: 900 W corresponds to 3.9 A and 1800 W to 7.8 A. The next table also covers pressures, air flow, 12 V consumption, dimensions and weight.
Pressures, 12 V consumption, dimensions and weight
In addition to the 230 V consumption, Truma publishes these 12 V consumption figures, together with pressures, air flow, dimensions and weight.
| Specification | Value |
| Pump pressure / system pressure | max. 2.8 bar / max. 4.5 bar |
| Air flow | max. 287 m³/h with 4 warm-air outlets |
| 12 V consumption, heating + water tank | 0.4 – 8.1 A |
| Heating the water tank only, at 12 V | 0.5 A |
| Consumption during 2 minutes when switching on and off | typical continuous current of 20 A, with possible peaks of up to 80 A |
| Quiescent current | approx. 0.001 A |
| FrostControl heating element (optional) | max. 0.4 A |
| Dimensions (L x W x H) | 510 x 450 x 300 mm |
| Minimum installation dimensions | 540 x 500 x 350 mm |
| Type approval | E1 122R–00 0232 and E1 10R–06 5277 |
| Weight | 15.6 kg (with peripherals: 16.8 kg) |
| Truma part number and EAN | iNet X Panel 2: 33417-20, EAN 4052816050768 |
The Combi D4E weighs 15.6 kg, which is more than the 14.8 kg of the Combi D4, because of its electrical elements. The peripherals are the control panel, the FrostControl, the diesel pump with its bracket, the flexible hoses, the cables and the fixings.
How the Truma Combi D4E diesel heater works
The unit heats the interior air with the diesel burner, the electric rods or both, according to the mode you pick. A circulation fan collects the cold air from the living area, passes it through the heat exchanger and then distributes it to the four outlets. The unit also picks the power stage according to the difference between the temperature set on the control panel and the ambient temperature.
The three modes of the Truma Combi D4E diesel heater
Because you can use all three modes to heat the living area, the table summarises when each one is the right choice.
| Mode | What it is for | How it works |
| Diesel | Stand-alone use, on the road or without electricity | The burner takes diesel from the vehicle's tank and the unit selects the power stage. |
| Electric 230 V | Stationary use on a campsite | 900 W or 1800 W is set by hand, depending on the fuse protection available. |
| Combined | Maximum performance for stationary use | With low demand, electricity takes the lead; the diesel burner only comes on when the demand for power is higher. |
If demand is high, for example when heating up the vehicle or at very low outside temperatures, Truma advises choosing diesel or combined mode so that enough power is always available. Also avoid the lowest setting for prolonged periods.
Hot water and looking after combustion
For hot water, use diesel or electric mode, but not combined mode: if you preselect it, the unit chooses electric and the burner does not switch on. With the water tank empty, you can also heat the living area in all three modes.
Truma also asks you to avoid continuous diesel operation with low demand for more than 10 days; in that case, use electric mode. If you cannot switch, heat the unit briefly once a day so that condensed water evaporates and combustion stays clean. During long stops, drain the water and switch it off, especially in frosty weather.
On the road and with HVO
According to Truma, the burner is high quality and fan-assisted so that it works well on the move, and the brand lets you use it while driving. For this, use diesel mode, since it is the stand-alone one. Do not run the vehicle's tank down to reserve, though, because the unit draws in air and the fuel arrives irregularly, with thick smoke and odours.
EN 590 diesel and EN 15940 synthetic diesel work as fuels, and Truma states that the heater is approved for pure HVO as well as for blends of it with fossil diesel and B7. It does not accept blends with more than 7% biodiesel, nor used oil, rapeseed oil, alcohol or petrol. According to Truma, the built-in pressure sensor also lets it heat at any altitude.
iNet X Panel 2 control panel
Because the Truma Combi D4E diesel heater comes with the iNet X Panel 2, according to Truma, this panel provides central control of the heating, the air-conditioning system and the Truma LevelControl. You can operate it from its capacitive touchscreen or from the free iNet X App, and also programme up to 6 timers.
| Item | Value |
| Display | 4.3" TFT-LCD touchscreen (capacitive) |
| Power supply and consumption | 12 V DC (8 V DC – 16 V DC), 1.5 W |
| Interfaces | TIN bus, CI bus, CAN bus and Bluetooth Low Energy (BLE) |
| Operating and storage temperature | -30 °C to 60 °C |
| Battery | CR 2032, service life of about 8 years; the app warns you when it needs replacing |
| Weight | approx. 190 g |
| Dimensions (L x W x H) | 89 x 118 x 31 mm |
| Protection | class III; front IP20, rear IP00 |
| Physical buttons | Home and Back |
| Mobile phones connected at the same time (iNet X App via Bluetooth) | up to 3 |
| Timers | up to 6 |
| Remote control | with the iNet X Connect module (optional, not included) |
| Manufacturer's warranty | 24 months |
Truma also describes an automatic climate control that adjusts the heating and the air-conditioning system to keep the temperature comfortable. It also shows the outside and inside temperature and, if there is a fault, clear error messages with suggested solutions. Updates arrive through the app via internet and Bluetooth and can take up to 15 minutes.
Remote control needs the iNet X Connect module, which is optional and not included; according to Truma, it does not work in Andorra, Bosnia and Herzegovina, Kazakhstan, Moldova, Ukraine, Turkey, Belarus or Russia. The screen goes to the lock menu after 60 seconds and to standby after another 60; in standby, other mobile phones can still control the appliances.
Installation and fitting
As Truma states, only qualified technical personnel carry out fitting, repair and functional testing. To complete the installation, the technician must also provide for:
- The exhaust system, with the Combi D pipe kit and its silencer, and the ZR 80 cowl.
- The water connection set with the FrostControl valve, in the FC TB or FC JG version.
- The fuel tank connection kit that suits the vehicle.
- The warm-air ducts, without which the unit cannot work.
- The connection of the 230 V mains cable for electric and combined mode.
- The yellow warning stickers, in a clearly visible place in the vehicle.
Anyone who is not a technician must not open the unit, fit it to another vehicle, modify it or repair it. Only a specialist technician may replace the 230 V fuse and the mains cables, and then only with an original Truma part.
Frost and the FrostControl
The FrostControl opens by itself below about 3 °C and empties the tank; you can only close it by hand, and then fill the tank, at about 7 °C or more. Because Truma excludes frost damage from the warranty, empty the tank if there is a risk of frost. An optional heating element also brings the valve up to about 10 °C so you can fill sooner.
What's in the box and the accessories you need
This is what the box contains for this variant with the iNet X Panel 2:
- Heater with room temperature sensor.
- iNet X Panel 2 control panel.
- Control panel cable.
- Fuel line.
- Metering pump.
- Fixings.
The following items do not come with the heater, so you must buy them separately:
- Combi D pipe kit with exhaust silencer and ZR 80 wall cowl, with inner and outer parts.
- Water connection set FC TB (36100-01) or FC JG (36100-02), the one that includes the FrostControl valve.
- Fuel tank connection kit.
- FrostControl heating element, optional.
- iNet X Connect remote module, also optional.
- Warm-air ducts and air outlets, which the box contents do not list.
Official Truma part numbers: exhaust and water
Truma's accessory list for the next-generation Combi D starts with these exhaust and water part numbers.
| Truma part number | Official accessory |
| 34502-01 / -02 / -03 / -04 | Complete Combi D pipe kit, with exhaust silencer 600 and Ø 80 mm combustion-air pipe, in lengths of 0.6 / 0.7 / 1.0 / 1.5 m. If you have to shorten it, you need the 35 mm locking-washer tool to fit the replacement washer (34020-45200). |
| 36140-01 | Inner part of the ZR 80 cowl with clamps (without outer part). |
| 36151-09 / 36151-10 | Outer part of the ZR 80 cowl, black or anthracite; Truma recommends these two heat-resistant variants for the Combi D (E). |
| 36100-01 | FC TB water connection set: FrostControl TB power-free drain valve, TB elbows for Ø 10 mm flexible water hoses and black flexible PVC hose (TB = barbed connection). |
| 36100-02 | FC JG water connection set: FrostControl JG power-free drain valve, JG elbows for Ø 12 mm rigid pipe and clear flexible PVC hose (JG = John Guest system). |
The fuel, cowl and extras part numbers then follow below.
Official Truma part numbers: fuel, cowl and extras
These are the remaining part numbers, which serve as a guide for your installer.
| Truma part number | Official accessory |
| 34020-01315 | 5 x 1.5 mm fuel line for the next-generation Combi D, sold by the metre. With it and the unit's own components, you can connect a vehicle such as a Fiat Ducato with a factory-prepared tank take-off and SAE connector, without further adaptations. |
| 34020-01669 | Wall cowl conversion kit for the Combi D (E): converts from the Combi D to the next generation and lets you keep using the old side-wall cut-out. |
| 34092-01 | Black BGC elbow for connecting directly to the warm-air outlets (outlet for Ø 65 mm or Ø 72 mm pipes). |
| 70070-01 | FrostControl heating element with 1.5 m cable, to fill the water tank faster regardless of the ambient temperature. |
| 47000-00140 | Alternative iNet X room temperature sensor (e.g. FFC2), for direct connection to the iNet X Panel control panel. |
| 34030-34700 / 34020-01581 | Window switches (the second one narrow) for automatic switch-off of the heating; the 34030-34700 suits common hinged caravan windows. |
These are official Truma part numbers, which we quote here as guidance, although they are not part of the box contents.
Who is the Truma Combi D4E diesel heater for?
The Truma Combi D4E diesel heater suits people who use a small or medium-sized leisure vehicle of class M1 or O and spend time both on the road and plugged in. For example, it suits:
- Travellers who alternate between the road and campsites and want a single heater for both.
- Anyone who prefers to use the campsite's electricity on long stops, instead of diesel.
- Anyone who travels in the shoulder season, when electric power is enough.
- Anyone facing extreme cold who wants maximum power from combined mode.
- Anyone who wants hot water on board, without a separate water heater, from diesel or from electricity.
If you need other equipment for your water system, have a look at the water heaters section.
Maintenance, cleaning and warranty for the Truma Combi D4E diesel heater
If the tank contains water, heat it for about 30 minutes at least once a month, and operate the FrostControl at least twice a year to release limescale. Check the exhaust system at regular intervals, at least every 2 years, and check the double pipe, the unit's mounting and the cowl, especially after long journeys.
The cowl must also stay free of snow, ice, leaves, tarpaulins and nests, and you should not spray it with pressurised water. A soft sponge and an outdoor plastic cleaner are enough when you clean the outside. If smoke comes out for more than 1 minute, switch the unit off.
If you park in an enclosed space, such as a garage, switch the heating off, deactivate the timer and do not switch it on remotely with the app: exhaust gases can cause poisoning.
Water tank and electrical protection
Firstly, sterilise and descale the tank regularly, using camping products, vinegar essence or citric acid. So that micro-organisms do not settle, Truma advises heating the water to 70 °C from time to time: choose diesel mode, set the water to 60 °C and leave the unit on for at least 30 minutes without drawing off hot water; the residual heat takes it up to 70 °C.
On the electrical side, the tank has a mechanical overheating switch that cuts the 230 V if the water gets too hot. If it trips, it is reset with the heater cold and disconnected from the mains, by pressing a red button under the connection cover; leave this to a specialist technician. Replace 12 V fuses only with original parts, and only while the battery is disconnected.
After a long stop, charge the batteries, then rinse the unit and the hoses with drinking water and check that the cowl has no damage or nests. Finally, any repair is a job for a specialist technician or Truma's after-sales service.
Manufacturer's warranty
Truma offers a 24-month voluntary warranty against material or manufacturing defects in the European Union, the United Kingdom, Iceland, Norway, Switzerland and Turkey. This warranty does not, however, affect the consumer's statutory rights against the seller.
Frequently asked questions
What is the difference between the Truma Combi D4E diesel heater and the Combi D4?
As Truma states, the Combi D4E is identical in construction to the Combi D4 but differs only in the integrated electric heating elements. That adds 230 V electric mode and combined mode, up to 3.9 kW, and it weighs 15.6 kg rather than 14.8 kg. The Truma Combi D4E diesel heater also keeps the 10-litre water tank.
Does the Combi D4E work on the move or only when plugged in on a campsite?
It works in both cases. Truma allows operation while driving in diesel mode, the stand-alone one. On a campsite, plugged into the mains, you can switch to 230 V electric mode or to combined mode if you need more power.
What happens if the 230 V supply cuts out in combined mode?
The control panel gives a warning, and then the unit switches to diesel operation. So the Truma Combi D4E diesel heater keeps heating even if the campsite power fails, as long as there is diesel in the vehicle's tank.
Which tank connection kit does my Renault Master or Ford Transit need?
On a Renault Master up to 04/2010, Truma recommends the TAS 01 or 09, or the TAS 03 if the take-off is prepared without an SAE connector; from 05/2010, the TAS 06. If your Ford Transit has an 80 l tank and the Camper package option, it is the TAS 05. Check the table and its notes before you decide.
What do I need to buy separately to install the Truma Combi D4E diesel heater?
The box does not include the exhaust system, the water connection set with FrostControl (36100-01 or 36100-02) or the tank connection kit, so you must add them. Nor does it include the warm-air ducts, without which it does not work. A qualified technician must also carry out the installation.
