Wherever your adventures take you, enjoy the creature comforts of warm water, for washing up or a quick wash down.

Pundmann campervan water heaters provide hot water on the go. The options for power are flexible and are offered in a range of combinations , including a hot air heat exchanger from an additional  diesel heater, and 12v or 230v heating elements. 

We offer the choice of size and style to suit your space, needs and budget. 

The Pundmann campervan water heater is designed for off road, on the road and off shore adventure. Perfect for boats, campervans, motorhomes , caravans, mountain top cabins, sandy shored beach huts, long distance lorry drivers, even the shed at the end of your garden.

The stainless-steel water tanks are all fully insulated, water is heated to 65°-70° in round an hour.

We recommend you install a thermostatically controlled mixer tap to dispense your water at a safe 40°- 45°C allowing even a modest tank of warmed water to go a long way. Water can be heating up whilst your underway and with the benefits of solar or wind charging of your 12v battery warm water can keep on flowing.

The Pundmann range of campervan water heaters are built so that you can stay wild, in off grid creature comfort.

£1.60 inc VAT

2024 Upgraded Units

Soft Shell:

The new EPP soft shell still provides all the benefits of the EPS shell.

EPP – expanded polypropylene foam is a high-performance superior insulation with exceptionally high strength to weight ratio and superior chemical, oil and heat resistance.
We have remained loyal to the soft shell however, as this has provided our installers so many benefits when fitting into tight spots.



We have modified the design of the stainless steel spigots to more easily enable our installers to convert their installation between 10mm internal diameter with hose clips to push fit connectors.

The 22mm extended smooth wall sits behind the barbed section that can be removed with a high quality pipe cutter or hacksaw.




Pundmann water heater wiring handy tips
plumbing guidelines for Pundmann water heaters
pundmann inside wardrobe of vw

Simple Installation Visual for the Hybrid & Diesel model

Combi diesel Pundmann


3 ways depending on the heater

  • 12v – Has a 180w (3L) or 200w (6L& 9L) immersion heater
  • 230v (240v compatible) has a 500w immersion heater

Air Model – uses the hot air flow from a diesel heater, efficiently through the cylinder heat exchanger


DC 12V     180W = 15.00 A
DC 12V     200W = 16.67 A

AC 24V     200W =   8.33 A


AC 240V    200W =   1.04 A

AC 240V    500W =   2.08 A

3 or 6 litre – Consider the availability of cold water and the space you have available

A modest shower uses around 5litres of water so our 6L model would provide more than enough water for a couple of showers

A 3L unit will provide adequate hot water for washing up and a quick wash down.

3l – (WxDxH): 228 x 217 x 200 mm

6l – (WxDxH): 228 x 360 x 200 mm

9l – (WxDxH): 228 x 520 x 220 mm

The units require approximately 85mm allowance to the depth for the pipes and pressure release valve

The working operating pressure for the water heater is 2.3 bar. The setting for the safety valve is 3.0 bar, if the pressure inside the cylinder increases to 3.0bard the safety valve will open and pressure will be released above. 


A hose should be attached to this and directed to a safe place in case of pressure release.


The safety valve is dual purpose and can be used to empty the tank of water for longer storage or winterising of you unit.



The units are all tested to above 4bar and are fitted with a 3.0 bar pressure release valve.



Heating times will vary according to the ambient temperature of the water, the size of the tank and the type of power you are using.


The 12V 3l tank has a 180W heating rod which takes approximately 60 minutes to achieve 70°C. 

The 230V heating rod is 250W and will be faster.


You can have both and use both at the same time for faster heating.


The built-in heating elements heat the water to 70°C and are controlled by an internal thermostat. The water heater must be full of water before turning any supply of heat on. The heating elements are 230V-500W, 12V200W depending on which heater you have chosen. You can have both and use both at the same time for faster heating.

If the temperature of the water falls below 65°C the heating rods will switch back on (and if there is a power supply.)



Warm water can create an environment for bacterial growth.


Legionella bacteria is commonly found in water. The bacteria multiply where temperatures are between 20-45°C and nutrients are available. The bacteria are dormant below 20°C and do not survive above 60°C.


There is no automatic cut off when using the air flow from your diesel heater so water can become very hot.

For safety against scalding, it is essential that you install a thermostatic mixing valve when installing an air heater.


A blender valve blends the hot and cold water before the water arrives at the tap controlling the maximum hot water temperature safely from the tap.


This is usually restricted to 43°C. It will shut off water supply if there is no cold water.


As well as being safe it increases the amount of hot water available.

Yes, the unit has an insulated jacket which will slow down the cooling of the warm water.

An easy option is to install a relay so the 12v water heater is only powered when the vehicle engine is running. 

If the boiler is not going to be used for a long time or winterising, the water must be drained from the boiler. Before emptying the boiler, it must be disconnected from all power supplies The boiler is easily emptied by

Opening the safety valve once the water has been drained from the rest of the circuit.

You might choose to add a release nut to make this easier.

Most 12v water pumps with a maximum 2.0bar / 30 psi with a flow rate of 10 litres per minute

A lower rated pump with 1.1bar/20psi and 7litres per minute is ideal. 

We are developing a solution for this presently so please check back with us soon.

No, this is not necessary as we install a pressure release valve.


We recommend all valves should be installed with a PTF or similar tape.  The use of Loctite 45 as ideal.


When wiring in the 12v unit you might consider a couple of options to minimise the risk of draining your battery.

·       An illuminated on / off switch

·       Wire the unit into your ignition loom

·       Wire into a suitable control panel

·       Install a Voltage controller (such as Solaris) which will turn on the electric element when the battery voltage hits a programmable threshold and turns it off when it drops below a separate threshold.

The AC units are designed to be hooked up directly to the mains power supply with a 5amp fused plug

Do not connect the 12VDC and 230V AC circuits together

Our water heaters have a 3-year return to base warranty

The Autoterm diesel heaters have a 2-year return to base warranty 


There are many Campervan / Motorhome installers across the UK who are technically capable of installing Pundmann Water Heaters.  For a list of Approved installers CLICK HERE .


For any further information on Pundmann Water Heaters in the UK please contact [email protected]