Elgena KB 3 water heater, 3 l, 12 V / 200 W - low-pressure boiler for caravans, motorhomes and boats
- Low-pressure Elgena KB 3, 3 l, 12 V / 200 W water heater for caravans, motorhomes and boats. Thermostat 30-80 °C, frost protection, PP tank for drinking water. For submersible, foot or hand pumps.
The Elgena KB 3, 3 l, 12 V / 200 W is a small low-pressure water heater with a capacity of 3 litres, designed for caravans, motorhomes, boats and food trucks. It works wherever space is tight and the power hook-up has a low fuse rating. Hot water is handy for washing hands and dishes, brushing teeth and a short shower, in summer and in winter. You set the water temperature steplessly between 30 and 80 °C, and in position F the thermostat keeps the water above freezing and protects the heater from frost. The tank is made of PP approved for drinking water and the heating element is V4A stainless steel / Incoloy. The heater is made in Germany by Elgena of Munich.
Key features
- capacity 3 l, dimensions 30 x 16 x 19 cm
- power supply 12 V / 200 W
- thermostat with stepless control 30-80 °C and indicator lamp
- frost protection (position F) and overheating protection
- PP tank for drinking water, V4A / Incoloy heating element
- for a submersible pump without check valve, foot or hand pump, max. 0.8 bar
- wall mounting with brackets included, Ø 10 mm hose connections
Power supply and heat-up time
The 12 V / 200 W heating element is designed for the battery system of a motorhome, caravan or boat. The manufacturer states a current draw of about 16 A, so the 12 V wiring and fuse must be sized for this load. The heater has a 1 m cable, 2 x 2.5 mm², without a plug. While driving you can use surplus power from the alternator. The manufacturer states about 15 min to 55 °C for the 660 W element, and the 200 W element has less than a third of that power, so heating takes correspondingly longer.
How to connect the water
The KB 3 is a low-pressure appliance. The simplest way is to connect it to a submersible, foot or hand pump. In this setup the heater can supply one or several taps. There must be no check valve in the pump or the lines, because the water expanding during heating needs a way out. To a pressure pump, an automatic pump or the mains you may connect it only through a low-pressure mixer tap and only to one tap, and the spout must stay open. Run the hoses by the shortest route, without kinks and on a steady rise, so that no water pockets form, and secure all connections with hose clamps.
Installation
The heater is mounted horizontally on a wall with the supplied brackets, fixing screws facing down. You can fit it on the right or left or on the back panel of a cabinet, so that the temperature knob is visible and easy to reach. The heater must be filled with water before you switch on the power. Open the hot tap and start the pump. The heater is full only when water flows from the tap in both the hot and the cold position.
Everyday use
- set the required temperature with the knob, the thermostat switches the element on and off by itself
- the indicator lamp lights up while heating
- when you do not use the heater, turn the knob to 0
- slight dripping from the spout during heating is normal and is caused by the water expanding
- mixed with cold water at the tap you get more warm water than the tank holds
In winter: frost protection
You have two options. First: leave the heater connected and turn the knob to F. The thermostat keeps the water above freezing and uses very little power. Second: disconnect the power, switch off the pump, empty the water tank and open the drain screw of the heater. Then open the tap so that air can enter the lines. Make sure the heater is completely empty, because even a little water left inside can burst the tank in frost. Fill the heater with water before using it again.
Protection against dry running
If the element is switched on without water in the tank, the temperature fuse in the element trips and disconnects the appliance. The fuse must then be replaced with an original Elgena fuse. So always fill the heater first and only then connect the power, and always disconnect the power before draining.
Related Elgena products
- Elgena KB 3 water heater, 3 l, 230 V / 660 W - version for a 230 V socket
- Elgena KB 3 Kombi water heater, 230 V / 660 W + 12 V / 200 W - two elements: for the campsite and the road
- Elgena KB 6 water heater, 6 l, 230 V / 660 W - larger 6 l tank, floor mounting
- Elgena replacement tank for the KB 3 heater - after frost or pressure damage, for the KB 3 with one element
- Elgena temperature fuse - spare part after dry running
Technical data
| Parameter | Value |
|---|---|
| Manufacturer | Elgena |
| Model | KB 3 |
| Type | low-pressure water heater |
| Capacity | 3 l |
| Power supply / output | 12 V / 200 W (approx. 16 A) |
| Power cable | 1 m, 2 x 2.5 mm², no plug |
| Dimensions (L x W x H) | 30 x 16 x 19 cm |
| Weight | 1.2 kg |
| Mounting | horizontal, on a wall, brackets included |
| Water pressure | max. 0.8 bar |
| Water temperature | 30-80 °C, stepless |
| Frost protection | thermostat position F |
| Heat-up time | longer than the 660 W version (approx. 15 min to 55 °C) |
| Heating element | V4A stainless steel / Incoloy |
| Tank | PP, suitable for drinking water |
| Insulation | PU foam with protective skin |
| Water connections | Ø 10 mm hose |
| Drain | manual, drain screw |
| Equipment | thermostat, indicator lamp, frost protection, overheating protection |
Frequently asked questions
Can I connect the heater to a pressure pump?
Only through a low-pressure mixer tap and only to one tap, with an open spout. The KB 3 cannot withstand the full pressure of a pump or the mains.
What water pressure is allowed?
The manufacturer states a maximum of 0.8 bar.
Do I need a safety valve?
No. The Elgena 3 bar safety valve set is designed for Nautic heaters and does not fit the KB 3.
How hot does the water get?
You set the temperature steplessly between 30 and 80 °C.
What should I do with the heater in winter?
Leave it connected with the knob on F, or disconnect the power and drain it completely through the drain screw.
Why does the tap drip while heating?
This is water pushed out as it expands during heating. It is normal.
Manufacturer
Elgena, Margaretenplatz 2a, 81373 München, Germany.