Truma Combi (E) Operating Instructions

Introduction and Overview

The Truma Combi (E) is a liquid gas heater with an integrated hot water boiler, designed for caravans and motorhomes. It provides both warm air heating and hot water.

Key Features:

• Warm air heating
• Hot water boiler (10 litre capacity)
• Fan-assisted burner for operation while moving
• Multiple operating modes (gas, electric, mixed)
• Optional FrostControl for automatic draining in freezing temperatures

Diagram of Truma Combi Unit (Figure 1)

The Truma Combi unit features the following numbered components:

• 1: Control panel, digital or analogue (no picture)
• 2: Room temperature sensor
• 3: Cold water connection
• 4: Hot water connection
• 5: Gas connection
• 6: Warm air outlets
• 7: Circulated air intake
• 8: Exhaust gas discharge
• 9: Combustion air infeed
• 10: Electronic control unit
• 11: Water container (10 litres)
• 12: Burner
• 13: Heat exchanger
• 14: Power electronics
• 15: Heating rods 230 V ~ (Combi E only)
• 16: Overheating switch 230 V ~
• 17: FrostControl (safety / drain valve – UK version optional)
• 18: Drain valve (UK version)

Symbols Used

The following symbols are used in this document:

• ⚠️ [Hazard Symbol]: Indicates possible hazards.
• ℹ️ [Information Symbol]: Note containing important information and tips.

Always observe ESD regulations when working with the electronics.

Intended Use and Proper Use

The appliance is approved solely for installation and operation in caravans (Vehicle Class O) and motor caravans (Vehicle Class M1), provided the gas system is installed according to EN 1949. National legislation and testing regulations for gas installations must be observed.

It is intended for heating drinking water and the vehicle interior. Operation while the vehicle is in motion requires specific safety features to prevent uncontrolled gas escape in accidents (UN-ECE Regulation 122). For commercial use, ensure compliance with local statutory and insurance regulations.

Improper Use

Prohibited uses include installation and operation in motor buses, commercial vehicles, boats, hunting lodges, weekend homes, or awnings. Heating liquids other than drinking water is also prohibited. Defective appliances must not be used.

Safety Instructions

Carefully read, follow, and keep these operating instructions. Failure to comply can result in serious material damage and risk to health or life. The operator is responsible for any such damage.

Working on the appliance: Only competent and trained staff are permitted to install, repair, and perform function tests. Always disconnect power and gas supply before working.

Gas Leaks: If you smell gas, avoid ignition sources, open windows/doors, evacuate the vehicle, shut off gas supply, and have the system inspected by experts.

Safe Operating Environment: Operate only with appropriate Truma control panels. Do not operate without a warm air duct. Be aware of toxic exhaust fumes in enclosed spaces. Keep the appliance and its air intakes clear of obstructions to prevent overheating. Do not place heat-sensitive items near the appliance or warm air outlets.

Children's Safety: Children under 3 must be supervised. Children aged 3-8 may operate the appliance only under supervision and with instruction. Children from 8 years old, and persons with reduced capabilities, may use the appliance if supervised and instructed. Children must not play with the appliance.

Operation while driving: Directive UN ECE R 122 mandates safety shut-off devices for operation while driving. If not installed, close the gas cylinder and attach information signs.

General Safety: Never use LP gas appliances when refuelling, in multi-storey car parks, garages, or on ferries. Do not spray water directly into the cowl.

Obligations of the Operator / Vehicle Owner

The operator is responsible for the water quality. The vehicle owner is responsible for correct operation. The Combi lacks built-in frost protection; use Truma FrostControl or drain the water if frost is a risk. No warranty claims for frost damage.

Pressure regulating devices and hoses must be replaced every 10 years (8 years for commercial use). Inspect hose lines regularly.

Liquid gas systems must comply with national regulations (e.g., EN 1949, DVGW Work Sheet G 607). Gas systems require expert inspection every 2 years.

Safe Operation

The exhaust cowl must not be blocked. Connection covers must be fitted. Use upright gas cylinders for gas phase extraction. Ensure operating pressure matches the appliance's rating (typically 30 mbar).

Recommended regulators: Truma MonoControl CS or DuoControl CS. Consider the EisEx regulator heater for temperatures around 0°C.

Maintenance / Repairs / Cleaning

Only experts may repair or clean the appliance. Maintenance, repairs, and cleaning must not be done by children. If the power supply line is damaged, it must be replaced by the manufacturer or a qualified person.

Warranty claims are void if modifications are made, non-original parts are used, or instructions are not followed. Thoroughly rinse water hoses before first use or after long periods of non-use.

The safety/drain valve should be operated twice annually to prevent blockages.

For cleaning, use suitable commercial products; avoid chlorine-based products. Heating the water to 70°C periodically can improve the effectiveness of cleaning chemicals.

Function Description (Combi / Combi E)

The Combi is a warm-air heater with an integrated 10-litre hot water boiler. It operates via fan-assisted burner, allowing problem-free use even while moving.

Heating Mode: Heats room and water simultaneously. The appliance automatically selects the operating level based on room temperature and set temperature. Water is also heated.

Hot Water Mode: Heats only the water, typically at the lowest burner setting. The burner switches off once the set temperature is reached.

Combi E Specifics: Includes heating elements for electrical operation. Offers three operating options: gas only, electric only (230V for stationary use), or mixed mode (gas and electric, only in heating mode).

FrostControl: At approximately 3°C, the FrostControl safety/drain valve automatically opens to drain the boiler, preventing frost damage.

Operating Instructions

Read safety and operating instructions before use. Instructions can be viewed offline via the Truma App.

Before initial use, flush the entire water supply with clear water. Materials in contact with water are safe for drinking water (see Manufacturer's Declaration on www.truma.com).

Control Panels: Described in separate instructions. Temperature settings are vehicle-dependent.

Room Temperature Sensor: Located in the vehicle to measure room temperature.

Safety / Drain Valve (FrostControl): Acts as a safety/drain valve. Drains water if frost is detected or if pressure is too high. Figure 3 shows its operation: rotary switch (a) for 'On'/'Operation', pushbutton (b) for 'Closed', pushbutton (c) for 'Drain', and drainage socket (d).

Opening/Closing the Safety/Drain Valve: Follow specific instructions for turning the switch or pressing the pushbutton. Ensure the drainage socket is clear. The valve can only be manually closed above approx. 7°C.

Heating Element for FrostControl: An optional accessory that heats FrostControl to approx. 10°C, allowing the boiler to be filled sooner.

Automatic Opening: FrostControl opens automatically below approx. 3°C.

Drain Valve (UK Version): Standard drain valve without frost protection. Equalizes pressure and drains water intermittently.

Filling the Water

Ensure the safety/drain valve is closed. If below 7°C, warm the compartment first. Switch on the pump. Open hot water taps until water flows without interruption, displacing air.

The boiler fills even if only cold water is used. Drain via the safety/drain valve if frost is a risk, even if not operated. Frozen lines can be thawed by heating the interior.

If connected to a central water supply, use a pressure reducer (max. 2.8 bar).

Draining the Water Container

If the vehicle is not used during frosty periods, drain the boiler. Switch off the pump. Open hot water taps. Place a container under the drainage socket and open the safety/drain valve. Ensure all water is drained.

Start-up

Combi: Heats interior with or without water.

Combi E: Heats interior in gas, electric, or mixed mode, with or without water. Ensure campsite power supply is adequate for selected wattage (900W/1800W). Unwind cable drums fully.

Check that the cowl is unobstructed. Open gas cylinder and supply valve. Fill water container if necessary. Switch on the appliance via the control panel.

Switching Off

Switch off the heater via the control panel. The switch-off procedure may take several minutes due to internal operations. Always drain water if there is a risk of frost. For long periods of non-use, close the gas supply valve and cylinder.

Maintenance

Fuses: Electrostatic discharge can damage electronics. Ensure potential compensation before touching. Disconnect 12V supply before opening covers. Always replace fuses with identical types (e.g., 10A quick-acting for 12V). Ensure covers are replaced to protect electronics from water.

230V Fuse (Combi E): For changing fuses or power lines, disconnect the appliance from mains at all poles. The fuse is in the power electronics. Use only 10A quick-acting fuses with interrupting capacity "H".

Work by Experts: Have an expert check and clean the appliance annually.

Work by User: Clean the installation compartment annually. Operate the safety/drain valve regularly to remove limescale.

Solar Systems: A battery or voltage regulator must be connected between the solar system and heater to prevent damage from irregular voltage. Disconnect charge regulator first when disconnecting battery, and connect it last when connecting battery.

Technical Data

Gas Type: Liquefied gas (propane / butane)

Operating Pressure: 30 mbar (see type plate)

Water Capacity: 10 litres

Heating Time (15°C to 60°C): Boiler approx. 23 minutes; Heater + Boiler approx. 80 minutes.

Pump Pressure: max. 2.8 bar (280 kPa)

System Pressure: max. 4.5 bar (450 kPa)

Rated Heat Output (Gas Mode): Combi 2 E UK: 2000 W; Combi 4(E): 2000 W/4000 W; Combi 6(E): 2000 W/4000 W/6000 W.

Rated Heat Output (Electric Mode): Combi 2 E UK/4E/6E: 900 W/1800 W.

Rated Heat Output (Mixed Mode): Combi 2 E UK/4E: max. 3800 W; Combi 6E: max. 6900 W.

Gas Consumption: Combi 2 E UK: 160 g/h; Combi 4(E): 160-335 g/h; Combi 6(E): 160-460 g/h.

Standby Heat Requirement (Gas Mode): 8.6 g/h.

Air Flow Rate (free-blowing): Max. 249 m³/h (3 outlets), Max. 287 m³/h (4 outlets).

Power Consumption (12V): Heater + Boiler: 1.2-6.5 A (Combi 2/4 E UK), 1.4-6.5 A (Combi 6 E). Boiler heating max 0.5 A. Quiescent current approx. 0.001 A. Heating element – FrostControl (optional): max 0.4 A.

Power Consumption (230V): 3.9 A (900 W) or 7.8 A (1800 W).

Protection Type: IP 21

Weight (without water): Combi 2 E UK: 15.5 kg (Heater), 16.0 kg (Heater with periphery); Combi 4 E: 14.4 kg (Heater), 14.9 kg (Heater with periphery); Combi 6 E: 14.4 kg (Heater), 14.9 kg (Heater with periphery).

Dimensions: Approx. 450 mm (width) x 510 mm (height) x 300 mm (depth).

Disposal

Dispose of the appliance according to administrative regulations and national laws (e.g., End-of-Life Vehicle Regulation in Germany).

Faults and Troubleshooting

Heater Faults: Refer to control panel operating instructions.

Water Supply Faults:

• Slow heating: Water container furred; descale system.
• Water not filling: Safety/drain valve open; close it.
• Boiler not draining: Drainage socket blocked; clear it.
• Water dripping from socket: Water pressure too high; check pump pressure (max. 2.8 bar) or use a pressure reducer for central water supply.
• FrostControl opens after shutdown: Ambient temperature below approx. 3°C. Switch on heater or use FrostControl heating element.
• FrostControl cannot be closed: Temperature below approx. 7°C or rotary switch not in 'Operation' position.

If problems persist, contact Truma Service.

Accessories

• Truma CP plus: Digital control panel with automatic climate control. Can be extended with Truma iNet Box.
• Truma iNet Box: For networking Truma appliances and control via smartphone/tablet app.
• Truma CP classic: Analogue control panel (not for Combi E).
• FrostControl Heating Element: Accessory to heat FrostControl.
• Control panel cables (various lengths).

Manufacturer's Warranty (European Union)

Truma provides a 24-month warranty against material and manufacturing defects for appliances purchased in EU member states, Iceland, Norway, Switzerland, and Turkey. The warranty covers repair or replacement at Truma's discretion. Defective parts become Truma's property.

Warranty Exclusions: Improper use, installation, operation, unauthorized repairs, wear and tear, non-original parts, foreign substances, unsuitable operating conditions, force majeure, or customer modifications.

Making a Warranty Claim: Contact an authorized service partner or the Truma Service Centre. Provide defect description, serial number, and date of purchase. Addresses are available at www.truma.com.

Contact Information

For service and support, contact Truma Service Centre or authorized partners:

Truma Gerätetechnik GmbH & Co. KG
Truma Servicezentrum
Wernher-von-Braun-Straße 12
85640 Putzbrunn, Germany

Phone: +49 (0)89 4617-2020
Telefax: +49 (0)89 4617-2159
Email: service@truma.com
Website: www.truma.com

Have unit model and serial number ready when contacting.