Frequently Asked Questions (FAQ) - Water heaters

1. How should the water heater be installed?
The water heater must always be mounted horizontally on the floor . Wall mounting or vertical placement is not possible.

2. Why are two drain taps included?
The water heater is supplied with two drain taps:

  • One for the vent

  • One to allow the water to drain completely (e.g. in case of frost or maintenance)

3. Is the heating element always on?
No. The element automatically switches off at 70°C. It switches back on again as soon as the water has cooled down to 55°C. This saves energy and prevents bacterial growth.

4. Can the water heater be used on 12V and 230V at the same time?
The Combi models are equipped with both a 12V and a 230V heating element, 12V for use while driving and 230V when on a campsite, connected to shore power or an inverter. It is possible to activate both elements simultaneously to reduce the heating time.

5. How long does it take to heat the water?
On average, it takes 20–30 minutes to fully heat the water, depending on the ambient temperature and the amount of water.

6. How do I best maintain the water heater?

  • Drain the boiler if there is a risk of frost.

  • Flush the boiler regularly.

  • Check the connections and drain valves a few times a year.

7. Is the water heater energy efficient?
Yes. Thanks to the automatic temperature control and insulated casing, the water heater remains energy-efficient. It only heats when needed and keeps the water safely at the right temperature.

8. How does the water heater work?
The water is heated up to 70 °C. Once this temperature is reached, the heating element switches off automatically. The water heater is well insulated and keeps the water warm for a long time. Only when the temperature inside the water heater drops to around 55 °C does the heating element switch on again. This cooling process takes on average about 12 hours, depending on the ambient temperature. Heating the water from 55 °C back up to 70 °C takes just about 15 minutes. This way, you always have hot water available quickly, without the water heater consuming energy continuously.

9. Are the SANYMO electric water heaters instant water heaters?
No, SANYMO water heaters are storage water heaters, not instant heaters.
An instant heater requires a very high power supply (3,000–6,000 watts), which makes it impractical for caravans, motorhomes and boats, they usually run on gas. We deliberately avoid gas and focus on a clean, electric future.
SANYMO storage water heaters operate with low power (e.g. 300 watts), heat 3, 6 or 10 liters of water, and keep it warm for a long time, ideal for mobile use, especially with solar and battery systems.

10. What happens if the water heater is switched on while there is no water inside?
Our water heaters are equipped with an integrated overheating protection that automatically switches off the heating element if there is no water in the tank and the temperature rises too high. This prevents burnout. However, it is important to always fill the boiler with water before use, as the protection is intended only as a safety backup.

11. Can the SANYMO water heater be used while driving?
No. Our electric water heaters are designed and certified as household appliances for use when the caravan or motorhome is stationary, for example at a campsite connected to mains power. The water heater must not be used while driving, as this application does not fall under the ECE R10 regulation (R10 only applies to equipment powered by the vehicle’s electrical system while driving). The water heater carries the CE marking and complies with all requirements for safe household use when stationary.

12. Which water pump can I use with my SANYMO water heater?
The SANYMO water heaters are pressure-resistant and compatible with all common water pumps used in caravans and motorhomes.
This includes both submersible pumps (installed inside the water tank) and pressure pumps (mounted outside the tank). For optimal performance, we recommend water pumps specifically designed for recreational vehicles.