Rex Nordic

FAQ - Rexener Bio Water Heater


Heater Consumption:

How much does the heater consume?

Advanced burner

The device has a patented oil burner with an electric fuel pump that circulates the combustion gases through pipelines with ceramic coating and create heat as infrared radiation.


Complete combustion

The triple combustion process ensures complete and clean combustion. Normal ventilation is sufficient.


Effective sound attention

The silencing system inside the exhaust pipe that compresses and expands the exhaust makes AIRREX very quiet – only 48dB.


Touch control

Simple soft-touch control panel with LED display and remote control.


Can I use the heater with seawater?

Rexener Bioheater should not be used with seawater as it can cause problems due to the high salinity and the warranty does not cover any damage that may occur.

It is strictly forbidden to use pool salt, for example to clean the pool. Pool salt can’t be added to water heated with Rexener Bioheaters.

Can I install the heater in an old hot tub?

Yes you can! Rexener Bioheater is suitable for all types of hot tubs

Can I heat my pool with this heater?

Yes you can! Rexener Bioheater heats up even larger swimming pools, up to 50 000 liters

Can I use biofuel?

Yes you can! Rexener works well with biodiesel.

Spare Parts:

Where can I find spare parts for the heater?

Our service covers the whole country. Our service car is constantly stocked with a comprehensive selection of spare parts. All Rexener spare parts are available from our warehouse.


Does the heater need a circulation pump?

Yes. The Rexener heater is so efficient that the heater does not operate optimally when in free circulation. If your pool (hot tub / pool) already has a circulation pump or sand filter system, you can take advantage of it with Rexener. If you do not already have a circulation pump or sand filter, you can easily order them from our online store while ordering a heater.

How do I install the circulation pump and filter?

Check our Download-page to find the installation diagram

What kind of circulation pump can be used with the heater?

Recommended circulation pump characteristics

Operating voltage 230V ~, 50Hz

Flow rate 6100 L / h 6 m.c.H2O

Highest flow rate 9.6 m.c.H2O

Minimum flow rate 2 m.c.H2O

You can also purchase a circulation pump from our online store.

Installation and Maintenance:

Where can I install the heater?

Rexener Bioheater can be installed up to 10 meters from a swimming pool or a hot tub. So it doesn’t have to be right next to the pool. The circulation pump handles water recycling.

It is good to place the heater in a place where it can be easily adjusted. It should be installed on a stable surface that is free of water. The heater feet are adjustable. The fuel tank requires a safe platform. Make sure the tank is located where it is easy to refuel.

Do I need to move the heater indoors in the winter?

It is not necessary to move the heater indoors in winter, especially if it is in use. If the heater is drained of water, it can also be stored outdoors.  Of course, it is always better to keep the device in a warm, sheltered place when not in use.

Does the heater have to be drained in winter (water / fuel)?

Water must not freeze inside the heater. If you wish, you can keep the water so warm that it does not freeze, so you do not need to drain the appliance. If the heater is not used (or the heat is not maintained), the unit must be emptied before frost.

The fuel remains in a weatherproof tank, so you don’t need to empty the tank even in frost. It is always advisable to change the fuel if the fuel stops for a long time.

In the frost, make sure that the heater uses winter grade fuel.

How do I drain the heater?

Behind the heater there is a drain plug for draining the water. So does the Rexener circulation pump.