Warm Shower Kit 2.0 – Heating & Hot Water for Your Camper
The Warm Shower Kit is an easy way to equip expedition vehicles, campers, boats and yachts with both a hot air heater and a hot water system. It combines an Autoterm air heater with the specially developed combiBOIL water heater. The result is a flexible system that is easy to install and maintain.
The key advantage of the Warm Shower Kit is the complete separation of the heater and the boiler. A fault in one component does not automatically affect the other. Thanks to the high-quality materials, robust construction and excellent pressure resistance, a boiler failure is unlikely. However, should a fault occur for any reason, the heater continues to operate completely independently. And that matters: not being able to take a hot shower is inconvenient. Spending a night at −20 °C in an unheated vehicle is a much bigger problem.
Hot water can be generated using the air heater, an electric heating element or engine waste heat, depending on the selected configuration. This means you can always use the most suitable energy source, whether you are staying at a campsite, travelling off-grid or have just finished a drive.
Key Benefits at a Glance
- Includes Autoterm air heater
- combiBOIL water heater with stainless steel tank
- Hot water via heater, electricity or engine heat
- Integrated frost protection function
- Supports a second water circuit
- Not a combined appliance – improved operational reliability
How Does the Warm Shower Kit 2.0 Work?
The Warm Shower Kit 2.0 can generate hot water in three different ways:
Using the Air Heater
The heat already produced by the heater is also used for water heating without requiring additional energy.
Electric Heating Element
Ideal when connected to shore power, when sufficient battery capacity is available or when your solar system is producing excess energy.
Using the Engine Cooling System
While driving, waste heat from the engine is used to heat the domestic water. This method also requires no additional energy input.
Depending on the situation, the most suitable energy source is always available. After several hot summer days, you may not want to run the heater, while after a long drive there may already be enough heat stored in the engine cooling circuit. If plenty of solar power is available, the water can simply be heated electrically.
Integration into the Engine Cooling Circuit – Flexible Possibilities
By integrating the boiler into the engine cooling circuit, a variety of applications become possible.
Use Engine Heat for Hot Water
While driving, the engine cooling circuit heats the domestic water stored in the boiler.
Preheat the Engine
Conversely, the boiler can be used to preheat the engine cooling circuit. The required energy is supplied either by the electric heating element or by the air heater.
Operate a Second Water Circuit
The heat stored in the boiler can be transferred to a second water circuit using a circulation pump.
Underfloor Heating or Towel Radiator via a Second Heating Circuit
The combiBOIL makes it possible to create a second water circuit. This can be used, for example, to supply an underfloor heating system or heated towel rail, increasing comfort inside the vehicle and helping damp clothing dry more quickly.
Depending on the application, an expansion vessel and a circulation pump may be required.
About the Term “Underfloor Heating”
The underfloor heating system is not intended to heat the entire interior in the same way as a residential building. Instead, it provides pleasantly warm floor surfaces and significantly improves comfort. Even a few square metres of heated floor area around the seating area can noticeably reduce cold feet and the typical chill associated with vehicle floors.
Example setup of a pressurized water system with a hot shower kit in a camper. The items included in the delivery are circled—you can also get (almost) everything else you need from us.
What Is Included in the Warm Shower Kit 2.0?
The Warm Shower Kit 2.0 combines an Autoterm air heater with the combiBOIL water heater into a coordinated heating and hot water system. In addition to the main components, the kit already includes numerous accessories for both the warm air and water installation.
The Heater
The kit includes the proven Autoterm Air 2D or Air 4D air heaters. These heaters have been used in expedition vehicles, campers, boats and yachts for many years and have established an excellent reputation thanks to their robust construction and reliable operation.
Particularly interesting for DIY installers: according to the manufacturer's specifications, the heaters may be self-installed without affecting the warranty. They are also supplied with E-mark certification, meaning no additional vehicle inspection or registration is required in many countries.
Autoterm heaters are fuel-efficient and comparatively quiet in operation. Additional silencers are available as an option for even further noise reduction.
Important Note
All heater functions – such as operating modes, altitude compensation and control options – correspond to those of the individually available units. Detailed information can be found in the product descriptions for the Autoterm Air 2D and Air 4D.
Please select the appropriate heating output and onboard voltage from the drop-down menu.
The Boiler – tigerexped x Autoterm combiBOIL
The combiBOIL has been specifically developed for use with air heaters. The boiler features a stainless steel tank with a stainless steel heat exchanger and is available in 7, 9 and 12 litre versions.
For versions equipped with a 110 V or 230 V electric heating element, the thermostat is integrated directly into the unit. Due to limited installation space, the 12 V and 24 V versions are supplied with an external thermostat module.
Fully Integrated System
The combiBOIL communicates directly with the Autoterm heater. Both the heater and the boiler can be monitored and controlled via the control panel.
The heater can automatically monitor the water temperature and regulate heating output as required. In most installations, this eliminates the need for a manually operated flap to redirect the warm airflow. At the same time, overheating of the water is effectively prevented.
An integrated frost protection function is also available. If the water temperature drops to 2 °C, the system automatically heats the water to 15 °C and maintains the surrounding air at approximately 7 °C. For extended periods of winter storage, however, the system should still be fully drained. The boiler is equipped with an integrated drain valve for this purpose.
Which Boiler Size Is Right for You?
The combiBOIL is available with capacities of 7, 9 or 12 litres.
Our recommendation:
- 7 litres: 2 people
- 9 litres: 3 people
- 12 litres: 4 people or more
As the water inside the boiler can be heated to temperatures of up to 80 °C, cold water is mixed in during use. This means significantly more usable hot water is available than the nominal boiler volume might suggest.
Please note that larger boilers require more installation space, take longer to heat up and consume more energy.
Scope of Supply
Heater
- Autoterm Air 2D, Air 4D or Twin Kit (depending on selection)
- for 12 V or 24 V onboard electrical systems (depending on selection)
- Pre-assembled wiring harness with AMP SuperSeal connectors
- Stainless steel exhaust silencer
- Fuel pump
- Intake silencer
- Fuel line
- Mounting hardware
- Autoterm Comfort Boiler Control panel
Boiler
- 1 × combiBOIL water heater with 7, 9 or 12 litre capacity
- Mounting hardware
Warm Air Installation
- 2 × adjustable warm air outlets
- 2 × adapters for the boiler connections
- 1 × asymmetrical Y-piece
Water Connection Kit
- 0.5 m silicone drinking water hose (blue)
- 1.0 m silicone drinking water hose (red)
- 1 × adjustable thermostatic mixing valve / anti-scald valve
- 3 brass hose tails with male thread
- 2 brass hose tails with female thread (one included exclusively with the Warm Shower Kit)
- 1 × liquid thread sealant
- 1 × straight hose connector
- 1 × T-piece for integration into the cold water line
- 6 × stainless steel hose clamps with smooth inner band
- 2 × smaller stainless steel hose clamps
What Else Do You Need?
Depending on the vehicle and installation layout, additional components may be required to complete the water system.
Heater Mounting Bracket or Installation Flange
For a straightforward and professional installation, we recommend using a suitable mounting bracket or installation flange. These components simplify installation, provide effective thermal isolation and help reduce the risk of installation errors.
The brackets are available in different versions for various floor thicknesses or, for example, for mounting the heater inside a storage locker. For the Warm Shower Kit, one of these mounting brackets is typically used. In our heater accessories section, you will also find mounting solutions for many other installation scenarios.
Water Hoses
The situation is similar with the water hoses. Every vehicle is different, and installation layouts vary from project to project. For this reason, the Warm Shower Kit 2.0 is not supplied with hoses in predefined lengths.
Important: If you intend to use the water for drinking or cooking, we strongly recommend choosing hoses with the appropriate drinking water certifications. This helps ensure that no harmful substances migrate into the water and that taste and composition are not affected by the hose material.
You can find drinking water certified hose for both hot and cold water systems here.
Our product range also includes water filters for disinfection and safe drinking water wherever you travel. To help you choose the right filter, we have published a comprehensive guide in our online magazine.
Pressure Reducer
Our boiler tank is manufactured from high-quality stainless steel and built to tight tolerances. Nevertheless, the inlet pressure should be limited to 1.5 bar.
In all pressurised water systems, as well as systems using submersible pumps with integrated or external non-return valves, a pressure reducer should always be installed upstream of the boiler and adjusted to between 1.0 and 1.5 bar. Here you can find pressure reducers with pressure gauge and without pressure gauge.
Water Pump
A high-quality water pump provides the required pressure and circulation for the system. It should be powerful enough to maintain a good and consistent flow rate, even when water filtration is installed, while also ensuring smooth and quiet operation. Durability and serviceability are equally important considerations. You can find a suitable pump together with a matching accumulator tank, which further improves system smoothness and reduces pump cycling, in this bundle at a special price.
The Autoterm Comfort Boiler Control (ACBC) control panel only controls operation via the air auxiliary heater.
Electric heating and the cooling circuit are controlled and monitored separately, see the following FAQ.
Depending on the heating method -electric, air heater, water circuit- the boiler temperature is monitored and controlled independently of each other.
This means the Boiler Control heater panel does not control the electric heating element or the cooling circuit. That is what thermostat relays are for -or, with the 110/230V boilers, the integrated control of the electric heating element.
Please follow the instructions of all devices -boiler and relays- for controlling and monitoring your combiBOIL!
For general information in advance, however:
If the combiBOIL is combined with the Autoterm Comfort Boiler Control (ACBC), the ACBC temperature sensor constantly measures the boiler water temperature while the auxiliary heater is running. If the measured boiler temperature rises above 85°C, the ACBC interrupts the heater's combustion and switches to fan mode until the boiler temperature has dropped to 75°C. After that, combustion continues. This function applies exclusively to heating the water with the Autoterm air auxiliary heater.
Electric heatingIf you heat the water electrically, the 12V and 24V versions of the boiler come with an external thermostat relay (TSR) in the scope of delivery (boilers from 11/23), which measures and controls the boiler temperature for electric operation, independently of the ACBC. The switch-on and switch-off temperature must be set in the TSR relay beforehand (see its instructions!). If the water temperature rises above 65°C (recommended setting), the relay switches the heating element off. If it falls to 60°C (recommended setting), the relay switches the heating element back on. The thermostat relay's instructions must be followed, and a switch must be installed upstream.
For the 110V and 230V (9L and 12L only) versions of the combiBOIL, the temperature control is integrated in the boiler. The heating element switches off at a fixed 65°C and back on at 56°C. We recommend connecting the heating element to the 230V mains via an illuminated switch for better control.
Cooling circuitIf you connect the boiler to the vehicle's cooling circuit ( Coolant circuit kit ), you also need to integrate a temperature control. For this you use another TSR temperature sensitive relay, which also measures the water temperature in the boiler and, by means of a switchable bypass, routes the coolant through the boiler or past it depending on temperature.
Here, too, follow the instructions of the temperature sensitive relay! At a temperature of 75°C (recommended setting) the relay should switch the bypass and pump the coolant past the boiler. At 70°C (recommended setting) the relay switches back and the coolant flows through the boiler again.
Heating via air auxiliary heater: approx. 1 hour, regardless of boiler and heater size).
When operating via the coolant of the engine cooling circuit, a heating time of approx. 20 min is realistic if the engine is running at operating temperature.
With electricity, the time depends on the power of the heating element. For example, heating a 7-liter boiler with 300W from 15°C to 65°C takes approx. 84 minutes. You can easily calculate the heating time yourself.
Calculate:
(target temperature in °C – starting temperature in °C) x boiler volume in L x 1.2 / boiler heating power in watts x 60 = heating time in minutes.
If you want to learn more about the heating times required, take a look at our comprehensive magazine article on this topic.
You should choose a heating element with on-board voltage (12 or 24V),
If an inverter is present, you can feed more electrical power into the boiler via a 230V heating element, which heats the water faster as a result.
Caution: The towel dryer must not have more output than the heater / heating element feeds into the boiler.
Note that the system should be installed as straight as possible to work efficiently. The smallest Hot Shower Kit (2kW heater + 7l boiler) needs at least 108cm of space before you can continue with individual air ducting/distribution.
For all other setups, heater and boiler sizes, you can roughly add up the lengths of the following components:
Everything that is needed equally for every installation -in a vehicle or boat- and is not individual, we have put into the Hot Shower Kit, so that it is in principle ready and functional.
Depending on your starting situation, you might still need the following:
Of course, our range also includes all other components for building the complete pressure water system, such as certified drinking water hoses, pumps and accumulator tanks, installation material such as clamp jaw clips etc.
In our online magazine there is a detailed article on what is included in which kit and what you might still need.
combiBOIL has a check valve that prevents pressure that builds up from expanding "back". To protect hoses and faucets or shower heads from damage caused by excessive (heat) pressure, an accumulator tank should therefore be used.
With long pipe runs, the accumulator tank is not strictly necessary if the pressure can distribute itself in the piping system.
In a vehicle, long standing times, changing water sources, warming and biofilm formation act together. Controlled water care improves hygiene and protects the entire system. The service life of drinking water point-of-use filters is extended by inhibiting bioactivity.
Chlorine-based products (e.g. Micropur Forte) may only be used strictly according to the manufacturer's dosage, in the cold water system and with limited contact time. Afterwards the system must be flushed thoroughly.
Not permitted:
These applications can cause irreversible damage.
Typical damage patterns are:
This damage is not caused by a lack of material, but by chemical misapplication.
Different disinfectants should not be used in parallel or alternately without flushing in between. This increases the chemical load and brings no hygienic benefit.
Recommended are high-quality plastics (e.g. PEX, PA, PPSU), gunmetal fittings and stainless steel fittings.
Brass is only suitable as dezincification-resistant DZR brass.
Not recommended are copper, galvanized steel and aluminum in water-carrying areas.
Overaged or wrong coolant primarily damages aluminum components and can impair heat transfer. The stainless steel heat exchanger is usually not the first component affected.
These notes apply to all our 316L stainless steel boilers, regardless of size or version.
Our boilers are made of high-quality 316L stainless steel (1.4404) and are designed for drinking water and hot water applications in vehicles. They are robot-welded and pickled and passivated inside and out to achieve a very high level of corrosion protection.
However, the service life of a stainless steel boiler depends not only on the material and manufacturing, but significantly on the way it is operated and on water care.
PERMITTED USE
Use of drinking-water-suitable disinfectants according to the manufacturer's instructions
IMPROPER USE
LIABILITY NOTICE
Damage caused by chemical misapplication, unsuitable disinfectants, overdosing, incorrect material pairings or deviation from this usage specification does not constitute proper use and can considerably shorten the service life of the boiler.
SUMMARY
Our boilers are designed for drinking water.The use of unsuitable chemicals or incorrect disinfection methods can lead to material damage and does not count as proper use.
manufacturer information:
tigerexped GmbH & Co. KG
Weseler Str. 82
Alpen, 46519
NRW, DE
info@tigerexped.de
responsible person:
tigerexped GmbH & Co. KG
Weseler Str. 82
Alpen, 46519
NRW, DE
info@tigerexped.de
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user manuals
- PDF User’s manual Autoterm Comfort Boiler Control (German, 07/2024) 1,8 MB (opens in a new tab)
- PDF User manual tigerexped combiBOIL (V3.2, production date from 10/24) 1,2 MB (opens in a new tab)
- PDF User’s manual with installation instructions Autoterm Air 2D / 4D / 8D / 9D (09/2026) 3,1 MB (opens in a new tab)
- PDF Error codes Autoterm Air heaters (German, V2.0) 78 KB (opens in a new tab)
- PDF Manual tigerexped hot shower kit 2.0 EVO (German, V8.0, 10/2026) 2,2 MB (opens in a new tab)
- PDF Installation and operating instructions Caleffi thermostatic mixing valves series 520/522 (58806.05, 05/2026) 413 KB (opens in a new tab)
